"Its true that servicing a diesel is slighty dearer than a petrol model"
Have you got any actual instances of this?. Does your local dealer/garage charge more for a diesel service than they do for a Petrol service?. If they do that may just be down to them charging more because they can, not because it actually costs more.
Diesels and Petrols both have air, oil and fuel filters that need to be changed at a service. They use the same oil, coolant and brake and transmission fluid so that can't be it. Brakes and suspension bits are the same, on the same model car of course, so where is this extra diesel serving cost coming from if not from the service manager's imagination and knowledge of what their customers will pay.
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Diesels used to need far more frequent oil changes, also with a heavy engine at the front tyres and suspension will inevitably wear quicker.
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I didn't state it, but I was refering to the costs of servicing the car now, not what it may have cost years ago. The service intervals are the same for petrols and diesels now, though we all now that they are too long, regardless of fuel type.
Which diesel models do you know of that wear front tyres and suspensions quicker than their petrol counterparts?.
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My 306.
It even says so in the CBCB.
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All this low mileage stuff justifying a petrol car is imo a load of rubbish.
Ever seen what happens to a petrol car driven low mileages in short journeys?
Been there done it.
Diesels last much longer in my experience.
(Exhausts/engines die on petrol cars driven short distances all the time. Diesels stand up far better imo to frequent stop start motoring. Having said that, you do need a good battery to withstand partial charging in winter)
madf
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It's ok Snaily - I'm one of the few who dislike diesels too.
No soul!
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It's ok Snaily - I'm one of the few who dislike diesels too. No soul!
We're kindred spirits then. Petrolheads united against the diesel foe. Diesel? ~ bleugh!
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L\'escargot.
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Its thee, me and the snail against the dieselheads then, Adam.
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Count me in as well, I just do not like diesel. I have driven modern cars with them in, including Passat 1,8T and BMW 2,0 tdsigcr(or whatever) and I prefer petrol. The Xantia 2,0 petrol engine purrs nicely at low revs and goes well at higher. Nothing to do with the engine but I also thought that the Passat and BMW interiors were bland and boring compared to the Citroen. It seems to me that the basic diesel concept of simplicity and long life has been abandoned in the quest for performance. I have always used a personal yardstick of 30mpg, if it does that then I am happy.
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Count me in as well, I just do not like diesel. I have driven modern cars with them in, including Passat 1,8T and BMW 2,0 tdsigcr(or whatever) and I prefer petrol.
>>
Er, the Passat 1.8T is actually a petrol. Which sort of says it all really.
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Looks that way Al!
Adam, I seem to recall you enthusing about my diesel Accord when you saw it at the North West meet. hmmm.
Anyway, this was my first diesel and I certainly wouldn't go back to petrol. I've never had diesel on my hands, carpets, feet etc., and the fuel consumption is brilliant. Performance is not that much down on my former six cylinder Omega, and that could move. Certainly, it's as quiet, and the Omega was a very refined motor.
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>.Adam, I seem to recall you enthusing about my diesel Accord when you saw it at the North West meet. hmmm.<<
You get special dispensation Robbie for having a) One of the nicest looking estates ever built aand b) It having a completely electric boot!
And c) For having a great dog in the back!
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1.7 corsa diesel will wear tyres and suspension parts quicker than petrol engine.yes i would say diesel cars cost more to maintane.
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"Its true that servicing a diesel is slighty dearer than a petrol model" Have you got any actual instances of this?. Does your local dealer/garage charge more for a diesel service than they do
I agree with your logic, but the petrol version of my car ie the 1.8T is about £80 cheaper on the interim service than the 1.9TDi. This is just a rip off, but it is also a fact.
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"Its true that servicing a diesel is slighty dearer than a petrol model" Have you got any actual instances of this?.
From What Car? magazine:-
2.0 diesel Focus £798 cf 2.0 petrol Focus £732, over 3 years.
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L\'escargot.
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Fact is, we need to find an acceptable substitute for BOTH petrol and diesel - and damned quick! The cost is going through the roof and lunatic regimes or politically vulnerable ones in the Middle East control most of the supply. Sooner we can dump the stuff completely the better.
In the meantime.......
It's diesel for me every time.
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Last year I traded in my 11 year old citroen zx 1.9d for a 10 month old c-max 1.6tdci. The old diesel was noisy and a bit sluggish, but gave 50+ mpg and was 100% reliable, cheap to buy and maintain. The new car had numerous faults which I wont bore you with but the engine itself was I thought disappointing. Even more sluggish than the zx until the turbo kicked it and it returned an mpg in the low 40s, well short of the advertised figure. I then began to read of more and more problems with these Ford/PSA diesels including dual mass flywheel replacements and many EGR valve failures. The c-max was eventually replaced by another which was worse - rattly and really rough sounding and within days a major oil leak at 12000 miles. I got rid and have reluctantly turned my back on diesel for now and bought a petrol Mazda. Mpg down in the mid 30s but I dont worry about how much the engine will cost when the warranty expires. Is any manufacturer out there working on a modern, less complex, non turbo diesel which will last as long as diesels of old even if it does take an extra few seconds 0-60 ?
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"Its true that servicing a diesel is slighty dearer than a petrol model". Have you got any actual instances of this?.
It may not be comparing like with like but I recently had identical main dealer services carried out on my Mazda 323TD and my wife's VX Astra 1.6 petrol (timing belts replaced and full service/MOT prep). The Mazda cost £600, the Astra £400. Apart from the more expensive fuel filter in the diesel, I can only assume the labour costs are higher for the Mazda eg it must have taken longer to replace the belt.
I too will be thinking seriously about switching back to petrol for cars where the service intervals are less than 18k. The Renault diesels have 18k intervals but is this too long to go without an oil change on a diesel never mind the synthetic oils that are used?
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Looks like I've kicked off a bit of a heated discussion! Please bear in mind though my original post, from which you may have gathered I've got a budget of less than 3 grand, so while I would dearly love to own a more modern performance diesel, and probably will do in the future, for now getting another diesel means limiting myself to 95bhp max and tractor-land acoustics...! Plus the short service intervals
Rock on...
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"2.0 diesel Focus £798 cf 2.0 petrol Focus £732, over 3 years."
Can't argue with that, and clearly, a 43p per week savings is nothing to be sniffed at!. Would be nice if they also provided a breakdown of what thoses costs were.
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" It's ok Snaily - I'm one of the few who dislike diesels too.
No soul!"
I would like to formally invite Adam to have test drive of my car and then hear what he has to say about it "lacking soul" afterwards. 8-)
Only stipulation is that the traction control has to stay on!!!.
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And I would like to formally accept that invitation.
Saturday good for you? ;-)
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And I thought it was only me who was standing out against the dirty, smelly, slippery advance of diesel...
Yes I do get the filthy stuff all over my shoes then the car carpets when I am trying innocently to fill with unleaded.
France has a deep love affair with derv, possibly because they tend to be very careful with a euro and politics here is slanted to make sure that the price of diesel is kept low. Presumably diesel drivers would be protesting in the streets if they had to pay a fair price for the stuff - if they couldn't think of anything else to protest about, that is. The end result is that every beautiful French town and village centre stinks of diesel exhaust. If anything will ever end the delightful French culture of sitting outside to eat and drink it must be that.
No matter how much the diesel brigade will deny it, their cars are noisy and only give an impression of performance because all the torque comes in so low down the rev range - it's a bit like having a hi-fi with a volume control that makes no difference after '3' or '4' although the knob is marked all the way up to 10.
And, no matter how much the fans will deny it, every diesel car I have ever experienced smells ineradicably of guess what when it is only a couple of years old and done only a few 10s of ks. I think it's a bit like being a smoker - you don't notice the horrible smell if you are one who lives with it.
Some time ago I spotted a magazine called just 'Diesel Car'. To have to have a magazine that defends why you are polluting the planet and spreading deadly diseases because you want to save 20 quid a year - how sad is that?
Rant over - for now...
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Peugeot/Citroen Hdis could need a new particle filter @ 72K miles. £700 at todays's prices so that skews the economics pretty badly! Mike H my car puts out less pollution than a petrol car, so I pay less road fund, and it has an expensive particle filter to protect the environment. (see first part of this post). I bet a year's motorsport plays h*ll with the environment but I don't see any copmplaints about that! Vehicles doing less than 10mpg, a fleet of jumbo jets flying them all over the world. Loads if pollution and none of it necessary.
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And I thought it was only me who was standing out against the dirty, smelly, slippery advance of diesel...
I actually agree with what you said. But have you ever taken a lungful of what comes out of a cold petrol car exhaust?
Give me some soot anyday.
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I have two catalysed Hondas, 2.0 and 2.2vti and the smell from both of them, when cold, is a bit like marzipan - quite nice really...
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I have two catalysed Hondas, 2.0 and 2.2vti and the smell from both of them, when cold, is a bit like marzipan - quite nice really...
Is the windscreen rose tinted too ;-)
I'll bet you start them up and leave them idling whilst you watch your garden grow :-)
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How did you find out where I live?
Unfortunately it's a bit hard to find because of all the black smoke from diesels under hard acceleration...
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Some time ago I spotted a magazine called just 'Diesel Car'. To have to have a magazine that defends why you are polluting the planet and spreading deadly diseases because you want to save 20 quid a year - how sad is that? Rant over - for now...
IMHO what is sad, or rather just comical, is that you can get so wound up about what fuel some people choose to use. "Spreading deadly diseases" - yeah when I go for a service I always make sure they top up the botulism canister. I agree diesel is smelly oily stuff, but dont try to pretend that petrol by comparison is mountain spring water. As a liquid its more volatile and gives off more fumes. I personally love the smell of petrol vapour, it has that highly toxic zing to it, on a par with permanent marker pens. Ive not been to France lately so have not experienced the choking diesel smogs. What IMO we all ought to be doing is start using bioethanol and biodiesel as a cleaner alternative, but the UK public at large doesnt seem to give a damn about that... Give it 5 years.
I always said I would never buy a diesel, because in the early '90's they were too slow and economy was irrelevant to me; but recently my annual mileage tripled and I 'took the plunge'. So now I spend £40 per month less on fuel, which might not sound like a lot but I'm saving up for a house deposit so every penny (or tenner) counts.
My car sounds and rattles like a tractor but with a tuning box fitted it has quite satisfactory performance, or can average 50mpg when I try hard.
To get back on topic, for me it comes down to mileage; if I went back to doing 8k per year I would switch back to petrol and buy something petrol with a turbo, or 6 cylinder 2.5 litres plus. If the petrol/ diesel price differential went up over 10p/litre, I would look at switching back to petrol. But for now I'm sticking with diesel.
;o)
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yeah when I go for a service I always make sure they top up the botulism canister.
Thanks for that - I now have half chewed flapjack stuck in my keyboard!
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No matter how much the diesel brigade will deny it, their cars are noisy and only give an impression of performance because all the torque comes in so low down the rev range - it's a bit like having a hi-fi with a volume control that makes no difference after '3' or '4' although the knob is marked all the way up to 10.
Good analogy. I don't know whether it's true or not, my driving experience of different cars is limited. I find that on the motorway though, the diesel would win.
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>> No matter how much the diesel brigade will deny it, their >> cars are noisy and only give an impression of performance because >> all the torque comes in so low down the rev range >> - it's a bit like having a hi-fi with a volume >> control that makes no difference after '3' or '4' although the >> knob is marked all the way up to 10.
Why then are many police forces using 530 diesels as pursuit cars ?
Why did Top Gear (an anti-diesel gang) find the 535D only a tiny fraction slower than the 540 V8 petrol around the track ?
Why did Top Gear find the 535D quieter internally than the 540 petrol ?
Its true that the characteristics of a diesel engine are different to that of a petrol, but in this case different doesn't neccesarily mean worse.
Basically as a rule of thumb, if you like hearing revs, dont buy a diesel, but if you like easy mid-range overtaking, get a diesel.
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Diesel vs petrol is very much a personal thing.
I know what you mean by getting a newer petrol for the money, as I did just that, but only for about 9-10 months before going back to diesel, but deliberately avoiding common-rail (Focus tddi).
The petrol I had was an Ibiza 1.2 12v, nice car, 47mpg, great heater, but no good on hills/fully loaded/over-taking.
I'd say test drive the petrol, see how the mid-range flexibility compares to what you're used to, and then decide if you could cope with maybe 10-15mpg less.
Your present Mondy 1.8td should go on for ever, if you should decide to keep it, and the Mondy Enthusists Group have a few tips for free extra oomph!
You pays your money, and you makes your choice...
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What do you drive now Andy?
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What do you drive now Andy?
'02 Focus tddi. The tdci is the common-rail Focus.
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My 1/3 million mile Maestro van, 2.0 turbo diesel, was swapped for 2.5 v6 Omega CDX estate 1997, some 15 months ago, as reported back then.
If one had been still made in 1997 & had been available, when the Omega came along, I'd have loved to have had a Montego Countryman diesel, instead.
But value for £$£$ the Omega is excellent , can't complain about 25-27 normal mpg, 33 best we got 'on a run'. With Optimax, of course!!
VB
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Demon, I made a similar switch a few years ago now, having run diesels for the first four years of driving in my student days but buying a petrol on getting my first job after uni. I did relatively few miles, not using the car to commute, so there was probably no cost saving by going diesel. Diesel vs petrol didn't really come into it - I just picked the car I wanted.
As you have found out, diesels have strong demand used that holds the prices up, in many cases more than offsetting the higher purchase price new. For your £3k budget, you will get a petrol that's newer/lower mileage/better spec/better condition when comparing the otherwise identical diesel. For something such as a VW group car it's particularly noticeable, less so on on the less desirable pre-TDCI Mondeo.
Aside from cost, there is the different driving experience but it sounds as though you may prefer the petrol. How much do you really have to trim costs down? Even if the petrol costs a bit more to run, if you can justify it for your extra driving enjoyment as you could well be spending at least an hour a day behind the wheel, then go for it.
I now run both a petrol and a diesel but the latter isn't for economy as I do so few miles. They're both great in different ways.
James
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I now run both a petrol and a diesel but the latter isn't for economy as I do so few miles. They're both great in different ways. James
My situation too, and I agree, it's your own choice. Life's too short! ;o)
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" And I would like to formally accept that invitation.
Saturday good for you? ;-)"
Monday would be much better, whereabouts are you?.
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Find yourself a really tidy, one trilby-wearing owner Cavalier - I had an earlier G-reg 2.0CD which gave 40 mpg so long as it wasn't being thrashed on short runs. Plenty of push if I wanted it, long-legged cruising on the m-way, handling adequate. Image low...
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It does also depend on your journey mix. I do a lot of very short trips, 2-10 miles, and a few 60-100 milers, all dual/mway, at busy times. I can't drive like a lunatic on the narrow, poorly maintained country roads on the short trips, and the long trips are usually in the day when anything over the limit is neither possible or sensible.
Hence a 90bhp TD Peugeot lump in the 405 makes sense - 40-45 mpg, and my local filling station is clean, with no diesel puddles. I like high milers, so I'd be changing oil at 6k whether it was petrol or diesel. The oil out of the diesel is far better for treating fences, posts, barn doors etc anyway, so I don't have to buy expensive creosote-replacement any more....
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>>Monday would be much better, whereabouts are you?.<<
You seem to be seriously considering this! Much as I appreciate (and question your sanity for trusting me!) I don't think I'll be able to because
a) I live about 15 minutes away from Liverpool and Manchester
b) I'm a 20 year old with only TPFT cover on his car and I'd be getting into a very fast, not very old, RWD 3 series. I don't think there'd be an insurance company in the world who'd touch me!
c) I wouldn't want to die if anything happened to the car ;-)
Needless to say I do appreciate it! I'm 21 in August so ask me again then!
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Well, I've read all the posts praising the quietness of diesels and, in view of such a large body of opinion against me, I was about to concede that I might just possibly be mistaken in thinking they were noisy.
And then I happened to walk through the supermarket car park. I had no trouble whatsoever distinguishing the clattering diesels from the purring petrols. The only way a petrol could be as noisy would be if all it's big ends were knackered!
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L\'escargot.
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I was 20 too Adam, no reason why your age should suggest you cannot drive. You are probably a better driver than I am.
I am 30 mins from Manchester, no excuse there.
If you would rather wait until you are 21, fine by me.
Why so worried about insurance, I wasn't trying to sell you the car. 8-)
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"I happened to walk through the supermarket car park."
If you are buying a car (petrol or diesel) and intend to park it in a supermarket car park and walk around it listening to the engine from the outside, then don't bother with either one!!. 8-)
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I'm beginning to really like you. A lot.
I don't know why I thought didn't live anywhere near me. Probably mixing you up with someone else.
You are probably a better driver than I am.<<
I'd at least be a passenger of mine before making a claim as bold as that ;-)
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" I'm beginning to really like you. A lot."
Ummmm...I'm married, and the only test drive I was offering was of the car!!!.
8-)
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Diesel may be noiser than petrol when doing 0 mph in a car park, but do 70 mph on a motorway and I'll guarantee the diesel is quiter. What's more, do that for 2 hours and compare how you feel at the end of the journey - Diesel wins hands-down in this test. Quiter and more relaxed. Thas was true 10 years ago when I test drove a Peugeot 306, even more so now. Personally, I think small petrol engines in small cars make sense for around the town - but big diesel engines in larger cars designed for eating the miles also make more sense.
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This is what AutoTrader says in it's "Buying Advice" section.
"What's so great about petrol?
Petrol engines are quieter, more responsive and faster revving than diesel engines.
They're generally cheaper to service.
They're catching up with diesels in the economy stakes."
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L\'escargot.
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>> Petrol engines are quieter, >>
Not at motorway speeds.
>>more responsive>>
Simply untrue.
and faster revving than diesel>>
True though not a benefit.
They're generally cheaper to service.>>
Again untrue.
They're catching up with diesels in the economy stakes."
With a long way to go, in the mean time diesels have caught up in the performance stakes.
I am not anti petrol, far from it, though lets give credit where credit is due.
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I just assume that AutoTrader's statement was well-considered and was based on authoratitive statistics.
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L\'escargot.
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I'm trying to be unbiased and to quote authoratitive sources.
Here's what the Department for Transport says.
"Based on current technologies diesel vehicles tend to be more fuel efficient and emit less carbon dioxide, the main greenhouse gas, than their petrol counterparts but produce greater emissions of particles and nitrogen oxides - the two air pollutants of most concern.
In urban areas, for instance, where the health effects of air pollution are most acute, the use of petrol would be preferable to diesel."
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L\'escargot.
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with some different spin:
"Based on current technologies diesel vehicles tend to be more fuel efficient and emit less carbon dioxide, the main greenhouse gas, than their petrol counterparts but produce greater emissions of particles and nitrogen oxides.
So whats more important? the life of the planet does not seem to be.
------------------------------
TourVanMan TM < Ex RF >
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>>In urban areas, for instance, where the health effects of air pollution are most acute, the use of petrol would be preferable to diesel.">>
A nice diesel would be lovely for the weekend run down to Sandbanks however one would have to leave it in Weybridge and still use the Bentley around town you know.
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A nice diesel would be lovely for the weekend run down to Sandbanks however one would have to leave it in Weybridge and still use the Bentley around town you know.
I bet you love Sullivans. ;o)
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I admit that I'm more concerned with the health of me and my family than the health of the planet. And if most other people are honest, so are they. The planet will still be here long after we've gone. In any case, I firmly believe that us mere mortals cannot significantly affect the life of the planet. Nature always finds a long-term solution to anything we do to the planet in the short-term.
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L\'escargot.
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It would be a mistake to assume that petrol engines don't produce particulates. They do. Very small ones. Very small particulates work their way into the lungs much more easily than big visible ones; they are also much more likely to remain airborne.
Then there is the unburnt benzine that emerges in quantity (several kilos in every tank of unleaded) from those petrol-engined exhausts. Carcinogenic? Let's just say you wouldn't want it on your food.
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I did of course mean benzEne.
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I've been driving Peugeot XUD diesels since I first started driving nearly 6 years ago and I have no intention of switching to a petrol, especially given the rocketing fuel prices. My 1994 vintage 306 1.9TD is on 176,000 miles and shows no sign of giving up just yet. It's a joy to drive and went from Leicester to St Ives and back last August- 600 miles on a tank of fuel. That would be unacheivable in most, if not all petrol engined cars. When my 306 gives up the ghost, I'll be looking at a 206, 306 or 307 HDI or a VW Golf TDi for a replacement.
Diesel do nicely!
Martin
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And the reason more fuss is made about diesel particulates is a) they are visible, b) they are measured by mass, missing the point about the potential for deep flow into the lungs and blood which is related to particle size c) the measurement techniques for ultrafines are more difficult than for mass alone, and therefore less used as it costs much more, d) the amount of ultrafines from (particlarly DI) petrols might be as much as diesel at high loads. However, the facts are sparse for the reasons above at c. and d. Finally, given that no-one is actually sure what are the effects of particulates (other than industrial exposure to other substances) there is no evidence of excess mortality that can be reasonably attributed to diesel, AFAIK. At the moment its more of a "well it ought to" type of argument. As for NoX: the leaner the mixture, whatever the engine, the more Nox is produced. As petrol gets more reliable at leaner mixtures to reduce fuel wastage, the tend is to higher Nox production. The alternative of course is to remain with richer mixtures and greater HC emissions, a failing of petro; engines where one of the substances emitted in greater quantities than diesel, during fuelling and whether the engine is running or not, is a known, proven, carcinogen.
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Chrysler sell two identically priced cars in the 300C range.
The 3.5Lt V6 petrol and the 3.0 Lt V6 Diesel.
The diesel is quicker 0-60
The diesel has a higher top end
The diesel has lower CO2 emissions
The diesel uses 38% less fuel on the conmbined cycle than the petrol (from Chrysler website)
The diesel has 50% more torque
I own a 300C diesel - both petrol & diesel look great !!
MTC
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The diesel has 50% more torque
Engine torque is only half the story. The thing that matters is torque at the driving wheels and of course this figure is never quoted in engine characteristics. It depends on the gear ratio of the wheels to the crankshaft. The torque at the wheels (ignoring drivetrain friction) is the engine torque multiplied by the engine speed divided by the wheel speed. With diesels engine speed divided by wheel speed is much lower. This is immediately apparent if you compare the maximum engine speed of a diesel with that of a petrol.
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L\'escargot.
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The diesel has 50% more torqueEngine torque is only half the story. The thing that matters is torque at the driving wheels and of course this figure is never quoted in engine characteristics. It depends on the gear ratio of the wheels to the crankshaft. The torque at the wheels (ignoring drivetrain friction) is the engine torque multiplied by the engine speed divided by the wheel speed. With diesels engine speed divided by wheel speed is much lower. This is immediately apparent if you compare the maximum engine speed of a diesel with that of a petrol. -- L\'escargot.
yes - I think
In MTC laymans speak
At 1500 RPM MTC gently leans on the go go pedal and the car takes off at a handy pace (due to the large amount of torque low down ?)
However at 1500 RPM, if MTC buries the go go go go go pedal the car kicks down a gear (or 2) and disappears rapidly into the sunset (due to the large amount of torue avaialable, allied to a decent gearbox and also because of a thumping big V6 30 lt engine).
at 4200 rpm it's all over and mr auto gearbox changes up for me.
So I've been told by a man in the pub (naturally I would never break any speed limit), at the 4200 rpm chnage up point in 3rd gear the 300C CRD is doing 90 mph - sweet.
& relax
MTC >> >>
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I just wish that motoring jounalists would refer to torque at the driving wheels instead of just engine torque. I blame them for propagating the idea that the be all and end all of acceleration is engine torque.
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L\'escargot.
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When I put my foot down in my 2.0 TDCi 130 at 50mph it takes off, it is pulling about 1650 rpm so torque is high and rising making over 250lb/ft by the time it hits 1800 rpm.
If I put my foot down in a 2.0 petrol Mondeo at 50mph it would be more leisurly and would require a change down to keep up, at 50mph it would be pulling iro 2000 rpm well over 1000rpm short of its max torque revs at which it produces over 100lb/ft less than the diesel.
Diesel torque at the flywheel is much, much, much, much, much, much, much, much higher, diesel torque at the wheels is only much, much, much, much, higher.
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Diesel torque at the flywheel is much, much, much, much, much, much, much, much higher, diesel torque at the wheels is only much, much, much, much, higher.
Less BHP though means the gearbox turns all that torque into forward motion though.
It's at a much handier place in the rev range in a diesel though.
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HOW many times did I need to say though, though?
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What we need is comparative data (petrol vs diesel) of torque at the wheels against road speed, in the various gears. Until we have that we are really just aimlessly chewing the fat. At the moment the diesel freaks are insisting that they're right and the petrolheads are insisting that they're right.
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L\'escargot.
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Not just question of torque, but also an ability to use it. Diesels tend to have narrower power/torque ranges, so more gear changing needed to keep the engine at peak. 16v petrol engines need to be revved/thrashed to produce their best, also not a very relaxing way to drive.
For pure driving comfort I'd rather have a bigger petrol lump. Only problem is that I'm not prepared to do only 15-25 mpg any more.
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Not just question of torque, but also an ability to use it. Diesels tend to have narrower power/torque ranges, so more gear changing needed to keep the engine at peak. 16v petrol engines need to be revved/thrashed to produce their best, also not a very relaxing way to drive. For pure driving comfort I'd rather have a bigger petrol lump. Only problem is that I'm not prepared to do only 15-25 mpg any more.
Problem is you need a relatively big petrol to get the same punch as a decent TD.
If I was considering a petrol I would look at the new Golf 1.4 which (apparently) has a turbocharger and supercharger. The super charger should kick in earlier and more quickly. Yet you should also be able to hang to the gears for longer.
But I just like the character of modern diesels, even the sound they make. Can't explain it. It's like having a Mini with a truck engine up front.
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What we need is comparative data (petrol vs diesel) of torque at the wheels against road speed, in the various gears. Until we have that we are really just aimlessly chewing the fat. At the moment the diesel freaks are insisting that they're right and the petrolheads are insisting that they're right. -- L\'escargot.
to be honest, I'm struggling to understand what your point is.
In laymans terms, a diesel engine gives a lot more grunt, a lot lower down the rev range.
After driving a selection of petrol and diesel cars over the last decade, I can't ever see myself buying a petrol powered car again.
MTC
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There is more, and less to it than torque. I have no idea what torque my engine produces, and at what revs.I don't really care, either. To get maximum torque the throttle needs to be wide open. It is not possible to drive too far in this state and remain on the road!
I prefere petrol, my car will pull away nicely in 5th on the level from about 30mph. If I want to pull away quicker, I can drop down a gear or two depending on my mood and the prevailing conditions.It's torque is adequate for my wants. It is also as quiet as the modern diesels I have been in at motorway speeds.
Each to his own, neither is right or wrong.
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>To get maximum torque the throttle needs to be wide open. It is not possible to drive too far in this state and remain on the road!
As I understand it diesels don't have a throttle as such; the air supply is always "wide open." I guess that's the reason for the low down torque with diesels.
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You still need to make use of the "unresticted" air supply by supplying enough fuel to use all the oxygen. Perhaps I should have said foot to the floor.
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I prefere petrol, my car will pull away nicely in 5th on the level from about 30mph.
So will my Renault master van. Long wheelbase high roof loaded with minimum 15 cwt at all times.................love it!
VBR..........................MD.
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I have just changed from a diesel Mondeo TDCi130, to a petrol Astra 1.6
For what it's worth, my thoughts are that for most of the journeys I do the smaller, petrol engined car is ideal. I have done two motorway trips this week, and the Mondeo would have been in its natural habitat, however I don't think any car would have been much better on the M25 and M11 yesterday evening. A lot of my driving is by myself, and I don't have a caravan to tow, so it seemed pointless to run a car whose overall costs were that bit higher. For most of MY travelling, the more flexible Vauxhall petrol engine is easier to use than the better grunt of the bigger diesel.
As far as fuel consumption goes, the Astra is about 4 mpg worse, with slightly cheaper fuel.
You pay your money, and take your choice, as someone said.
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>> What we need is comparative data (petrol vs diesel) of torque >> at the wheels against road speed, in the various gears. Until >> we have that we are really just aimlessly chewing the fat. >> At the moment the diesel freaks are insisting that they're right >> and the petrolheads are insisting that they're right. >> -- >> L\'escargot. >> to be honest, I'm struggling to understand what your point is.
The point is that (1) acceleration is proportional to torque at the wheels not engine torque. (2) Torque at the wheels (ignoring drivetrain friction) is engine torque multiplied by the engine rotational speed and divided by the wheel rotational speed. Diesel cars are lowered geared than petrol, i.e. for a given road speed (and hence wheel speed) the engine speed of a diesel car is less than that of a petrol car. This means that, going back to point (2), a diesel car loses out proportionally on torque at the wheels compared to a petrol car. Unfortunately, without actual data of engine torque against engine speed, and gear ratios, (which I don't have and which nobody seems to be able to give me), I can't give mathematical proof.
And without mathematical proof this discussion is going nowhere.
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L\'escargot.
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We should forget torque all together. It justs confuses people talking about a static force.
The easiest way to compare is to see the power versus revs (the full curve). Or torque versus revs as one directly implies the other. Or compare the total area under the graph...
Or instead of x lb-ft at y revs, they should say x BHP at y revs.
The problem with diesels is they are non-linear - and this is exaggerated by higher gearing. E.g. to get same power at 1000rpm as 2000rpm requires double the torque. But the torque curve falls of the cliff. OTOH it climbs the cliff pretty quickly in the other direction.
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We should forget torque all together. It justs confuses people talking about a static force. The easiest way to compare is to see the power versus revs (the full curve). Or torque versus revs as one directly implies the other. Or compare the total area under the graph... Or instead of x lb-ft at y revs, they should say x BHP at y revs. The problem with diesels is they are non-linear - and this is exaggerated by higher gearing. E.g. to get same power at 1000rpm as 2000rpm requires double the torque. But the torque curve falls of the cliff. OTOH it climbs the cliff pretty quickly in the other direction.
Ziggy, I think that this is clearer
Chrysler 300C 3.5Lt V6 Petrol £25750 0-60 9.2,topend 136,25.7mpg
Chrysler 300C 3.0Lt V6 Diesel £25750 0-60 7.3,topend 143,34.4mpg
Hmm, I think I'll have the petrol (for half a nanosecond before I slap myself)
MTC
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35mpg?? For something the size of Surbiton on wheels, that's very impressivem, especially an auto.
Makes you think twice about 'Yank tanks' (Nearly ;o)
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35mpg?? For something the size of Surbiton on wheels, that's very impressivem, especially an auto. Makes you think twice about 'Yank tanks' (Nearly ;o)
whoops my typo.
the official figure for combined cycle is actually 34.9 mpg for the diesel.
On a recent 110 mile round trip on A roads I got 37 mpg, the best I've managed on a speed limit abiding (aren't they all ?) 120 m ile trip was 42 mpg.
It's a piece of kit alright. The engine, chassis & gearbox come from Uncle Mercedes, the looks are Pure American.
MTC
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Who really cares about torque when we all accelerate at about the same rate overall - certainly from 0 to the legal limit.
I'm more concerned about the filthy, greasy, smelly stuff that gets on my shoes, then into my car, and stinks up the place when I am entitled (I believe anyway) to breathe (relatively) fresh air.
I really can't believe that a few extra mpg is worth the bother of having to put on rubber gloves to stay clean during a simple job like putting in fuel.
Of course, I drive a Honda - a firm that has only recently had to succumb to pressure from the penny savers and their politicians to produce a (class-leading) diesel engine after leading the field in producing economical petrol motors.
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Fourtunately, as a diesel driver, I use the same pump island as yourself so I ensure that there is plenty of greasy filthy smelly stuff to get on your shoes and into your car.
I havent found a way to get it on your hands yet but I will.
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TourVanMan TM < Ex RF >
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I havent found a way to get it on your hands yet but I will.
No way will you find a way to get it on mine!
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L\'escargot.
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mike hannon, you're a man after my own heart. (That doesn't sound right somehow, but I'm sure it's the right expression.)
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L\'escargot.
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I'm more concerned about the filthy, greasy, smelly stuff that gets on my shoes
Plays hell with my Guccis. I suppose it wouldn't be so bad if you wore industrial footware.
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L\'escargot.
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Honda - a firm that has only recently had to succumb to pressure from the penny savers and their politicians to produce a (class-leading) diesel engine after leading the field in producing economical petrol motors.
Class leading, in what? Power, torque, refinement or economy, no! The refinement is ok though it is not a class leading diesel engine.
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Ziggy, I think that this is clearer Chrysler 300C 3.5Lt V6 Petrol £25750 0-60 9.2,topend 136,25.7mpg Chrysler 300C 3.0Lt V6 Diesel £25750 0-60 7.3,topend 143,34.4mpg
If only things were that simple.
If only.
A 0-60mph time is a good starting point for comparing performances, but even this has it's limitations. For a start the time is obtained using brutal take-off and gear-change techniques that only a nutter would use on his own car. And, as with engine torque figures, it is not the whole story. A car with a quicker 0-60 time will not necessarily have travelled a greater distance by the time it reaches 60. The reason? It depends on how the torque (and hence the acceleration) varies over the time and distance. A far better criterion would be to quote a standing start quarter mile (or whatever) time. As for top speed, this criterion is virtually of no value whatsoever except for academic purposes. The distance (and time) taken to reach the maximum speed is enormous ~ we're talking literally miles ~ even for a Chrysler 300C 3.0 V6 diesel! And if the wind speed or gradient alters during the run the maximum speed will vary from one run to another. And a car with a lower top speed could conceivably reach, say, 90% of the maximum speed of a faster car in a shorter time and distance. I could mention a lot more anomalies, but in the final analysis you'd be better off just reading No FM2R's post!
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L\'escargot.
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If only things were that simple. -- L'escargot.
L'escagot
I'm stumped as to how obtaining a 0-60 mph time would be different in a diesel car to a petrol one. In the case of the 300C's (that I have used to make my point), both are automatics si it is a simple task of planting your right foot and letting the engine & gearbox do the work. I've tried, I've really tried to get some 1/4 mile times but I've come up with a blank.
So back to my original point (& one which you seem to be struggling to accept), Chrysler market 2 x identically equipped cars for the same price - the only differnce being that one has a smaller diesel engine which outperforms the larger petrol engine.
It's quite simple.
Or you could have a look at any of the multiple roadtests that have benn made of the diesel that come to the conclusion that - yep it's a really good car & the pick of the range.
Here's a road test for you that you may find interesting.
www.honestjohn.co.uk/road_tests/index.htm?id=193
particularly this line about 1/2 way down
"The astonishing thing about the 300C CRD auto is it?s also the best of the range to drive"
MTC
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Ziggy, I think that this is clearer Chrysler 300C 3.5Lt V6 Petrol £25750 0-60 9.2,topend 136,25.7mpg Chrysler 300C 3.0Lt V6 Diesel £25750 0-60 7.3,topend 143,34.4mpg
<>
>A 0-60mph time is a good starting point for comparing >performances, but even this has it's limitations.
I think maybe we should all agree that 0-60 is actually a very poor performance metric (!) OK, maybe we are not going to agree, but if a diesel can match a petrol for 0-60 that is really impressive because it typically requires 1-2 more gear changes.
I would look at 30-50 in 4th gear as a metric, factoring in the gearing (too low = 'cheating'), as this makes the most difference to most people in the real world. Another rule of thumb: can I get decent acceleration in town without exceeding 2000rpm...?
Recently I drove a new Astra 1.6. Initial throttle response very crisp. Then, nothing. Sure you could rev it for longer but it was just more noise. Compared with an old Mk IV Golf with very long legs (was not even the highest powered version) was much, much more lively pulling from 1500rpm.
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>> Ziggy, I think that this is clearer >> >> Chrysler 300C 3.5Lt V6 Petrol £25750 0-60 9.2,topend 136,25.7mpg >> Chrysler 300C 3.0Lt V6 Diesel £25750 0-60 7.3,topend 143,34.4mpg <> >A 0-60mph time is a good starting point for comparing >performances, but even this has it's limitations. I think maybe we should all agree that 0-60 is actually a very poor performance metric (!) OK, maybe we are not going to agree, but if a diesel can match a petrol for 0-60 that is really impressive because it typically requires 1-2 more gear changes.
Hi ziggy
from the above figures you can see that the diesel doesn't just match the performace figures for the (larger) petrol engined 300C, it destroys them !!
perhaps the 300C isn't a fair example (for petrol enthusiasts) because the endine that is in the car is an absolute belter.
As for the gearchange suggestion, I'm afraid that is a bit of a non-starter, my car clears 60 mph in second.
I've tried to get 30-50 mph in 4th figures, but nowt doing - I don't know if that really matters as both cars are autos and it would kickdown any way.
MTC
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<< Or compare the total area underthe graph...
Now you're talking.
But unfortunately this concept is even harder to explain than torque at the wheels, and I don't seem to have got anywhere with my line of reasoning. You stand no chance with yours!
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L\'escargot.
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L'escargot.
You are quite correct regading the torque at wheels, it is a sound point well made however while a TDs torque advantage at crank speeds is reduced at the wheels it is still a substantial advantage.
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while a TDs torque advantage at crank speeds is reduced at the wheels it is still a substantial advantage.
cheddar, you may be right, and I may be wrong.
Unfortunately I don't have sufficient data to be able to present the true facts, and I prefer to have facts rather than impressions. I can't change the way I am because I had a working lifetime of having to be that way ~ my job demanded it.
Regarding impressions of acceleration, I remember an experiment being carried out many years ago at work. A group of people were presented with two cars that were identical except that one had a stronger accelerator pedal return spring than the other. They weren't told what the difference was, or even whether there was a difference, and they were asked to drive each car in turn on a test track and to say which had the better acceleration. They all said that the car with the stronger pedal return spring accelerated better. The springs were then swapped and the experiment repeated. Again, the opininion was that the car with the stronger spring accelerated better. Strange but true.
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L\'escargot.
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In the absence of other means to prove the point, examination of comparitive 30-50, 50-70 in-gear times will show how feeble similar displacement petrol engines are until doing 4000 rpm, by which time the diesel of similar size will be well ahead. I think it was in Autocar that someone was complaining slightly that his Porsche could not get past a diesel Accord on a twisting road, pulling from a corner. He could get alongside, but not past! Then time for the bends. How frustrating that must be:)
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