I must admit I have been a staunch anti-diesel man all my car owning life but I will be very tempted come the time to change my current car.
My cousins 320d simply blows my car away when it come to 3rd gear and above acceleration.
I'm a loser, baby....so why don't you kill me?!
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I can't understand the obsession people seem to have about how slow they can go in the higher gears. All that loading on the major engine and transmission components does the car no good at all. The engine likes to breath and stretch itself, reving the thing (Within reason) is far better than labouring it with regard to long term reliability.
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Tom - let alone the massively reduced safety margin by deliberately being in the wrong gear.
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Leatherpatches - if my car only gave me 30 mpg, with fuel at its current exhorbitant price, I'd be suicidal. I do 500 miles a week for goodness sake!!
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My dad is thoroughly obessessed with being able to be in 5th gear at 30 something miles an hour. Having a car pick up with gentle acceleration at low speeds is a sign of flexibility but not something I do on a regular basis. I think it is an old man thing :-)Diesel suits him because he drives in a very narrow rev range whereas I like to use more of mine so a diesel (unless a very petrol like one) would irritate. I have tried to tell him that being in the wrong gear doesn't do things any good but he thinks that if you keep the revs low as possible you will get the best fuel economy. Trying to persuade him that is not necessarily the case (I wish there was proof!) is an impossible struggle. He does about 15k a year and changes cars every 5-8 years , usually buying something about 2-3 years old and so far nothing that could be attributed to staying in higher gears has actually failed.
teabelly
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"..an old man thing"
I think it's to do with times past, when (petrol) engines had longer strokes and too many revs were to be avoided at all costs, because things would break. As you say, diesels suit people who drive in this mode, but whether you regard it as easier is a moot point. Horses for courses, really, but I've always found petrol more entertaining...
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My experience of diesels has been that I often stall them when at junctions - why? - because in my petrol car I was always taught, and spookily enough it has stuck, to approach a junction in second and if you don't actually need to stop then pull away in second. I have found with VW 130PD, Renault 1.9CDi and Mondeo TDCi amongst others I have stalled by trying to pull away in second. As always I guess practice will make better.
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"approach a junction in second and if you don't actually need to stop then pull away in second."
The reason for this was that (in the bad old days) cars did not have synchromesh on first. First was only used from standing start. To compensate, they had a low second.
Now, first should be used in all cars for driving at walking speed - e.g in Tesco's car park.
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TrevP and AlanGowdy: both fair enough points.
I was only getting 38mpg out of my old 306 Dturbo, however. This is not a great increase on 32mpg out of current car. Certainly not enough to offset the additional costs involved.
I have done nearly 4k miles since the 9 May when I got the car. This is with measures taken to ensure my mileage is kept down! (lift sharing etc.)
When objective figures are produced on fuel economy (i.e. independant tests and not owners or manufacturers figures), even low consumption cars that quote 50+mpg like the TDi golfs only get 40/41 mpg.
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I think pulling away at idling has more to do with the engine management system than whether it's petrol or diesel.
My 93 Volvo 240 has an electronically-controlled idle set at 800rpm.
If I simply let the clutch up slowly the car pulls away and continues to idle at 800, travelling at about 3mph. The engine speed hardly varies as the clutch bites. The same if I change into 2nd. I assumed this was normal on all modern cars.
It is on old models that you need the skill of 'adjusting the revs' as you let the clutch in.
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I think pulling away at idling has more to do with the engine management system than whether it's petrol or diesel.
Exactly right. Try letting a modern ford diesel pull the car along at idle in second gear+. Most of the time it won't, especially the new transit. Its the same thing that causes the TDCi starting/cutting-out problems.
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Yes, the ECU intervenes at low speeds and when decelerating in my Focus TDCi. Pulling at idle in second gear, the revs surge and the car lurches forward - not good in a queue of slow moving traffic! Also stalls when slowing down approaching junctions etc. Apparently parts of the engine (the flywheel?) can shatter at low revs and the ECU speeds up or cuts the engine before that can happen, or so say the experts on the owners club forum.
Never had these problems with my 1987 309 XL 1300.
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Personally, I find petrol cars much easier to drive than diesel cars. If you want to pull away from stationary in any gear other than 1st, get an auto.
I find that 'hitting the sweet spot' in a diesel much more difficult, you need to know the right rev band, you need a gearbox that has the right ratios.
Without that, diesel are very difficult to master for safe overtaking and good progress. I was in Cornwall last week and stuck on the A39 for a long time with a car full behind a car and caravan doing 40 down a national (Grrr).
When it came to overtake, I had to check revs (not enough, only 1300), work out where the gear lower sits at that speed (at 1700), so changed down, had revs, mirror, signal, hit the pedal, turbo and torque at peak, made progress, near hitting top of the powerband, had to think about revs in top at 60mph (2000), so changed up and got more out, mirror, signal, pulled it, checked speed at 70, eased off. Phew!
Overtaking complete.
With a petrol, it's much easier. They have much wider power band making this an easier affair.
As for riding on the clutch, you can do that with most large engined petrol, in fact with the choke out on my 3500S and impressive 15mph is possible in second without any throttle at all.
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After driving my mum's petrol fiesta for three years before recently getting my own car, a 1995 306 DTurbo, i can definitely say that IMO diesels are certainly no harder to drive, as in my daily queueing to work i no longer spend the whole time changing between 1st and 3rd, and on the motorways rush hour joining is made much easier by the punch of the turbo helping to pick out a space. Plus the TD is SOOOO much more fun to drive when you get nice open roads to play on!
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I think 3500 has hit the nail on the head there. Overtaking in my Focus TDCi was always a hairy business. Not so in the Civic though, 2nd gear, into the VTEC and your gone!
As for holding high gears, my SD1 would happily climb up Holliwell Hill in St. Albans in 5th at well under 1000 rpm!
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My Clio dci is not so nice in stop-go traffic as her indoors Ka.
For sure, the Clio won't stall on idle but it tends to "launch" forward slightly as the electronic injection compensates for the revs trying to drop, then after the inital launch the engine then brakes sending you forward in your seat a bit. Slightly exaggerated, but you get the idea. Then if you decide to use the "throttle" at these slow speeds, its a bit like an on-off switch. A little practice with clucth slip and a sensitive right foot helps.
The Ka will stall at a sniff of the clutch without a touch of throttle, but once moving in traffic is wonderfully flexible as regards picking up smoothly from low revs in 2nd gear etc.
Of course, out on the open road the Clio is the better car as regards overtaking/hillclimbing etc.
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" First was only used from standing start. To compensate, they had a low second."
Eh? You only need synchro to change into a gear, and there are very few occasions when one actually needed to change into first on the move. That's still the case, in my experience, so why first gear for car parks? As it happens, I can change into reverse on the move, although I don't use that much, either!
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3500s;
I re-read your overtaking account and simply did not understand it.You were travelling at 40 mph but only turning 1300rpm. You had to change down and then back up during the overtaking manoeuvre because you had reached the rev limit. Sorry, but at 1300rpm you must have been in 6th gear. Once you are in the powerband a car and caravan would be passed in a few seconds well before reaching the rev limit. I recently moved back to petrol from diesel and the worst aspect of the new motor is the need to move into 3rd or even 2nd to overtake. I know there are wondercars which have huge amounts of power but for easy overtaking give me a turbodiesel any time.
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"I re-read your overtaking account and simply did not understand it."
Oh, I understand it - it's again with the being in 6th gear at 40mph nonsense.
4th gear at 40 and Hey Presto "problems" disappear.
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JBJ - "why first gear for car parks?"
Erm, what other gear do you suggest for 4mph?
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most cars are "first gear is for pulling away from standing, change up to second as soon as possible"
My Golf manual states not to use first for more than afew yards.
So I suppose the answer is 2nd
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All this talk of gear changing makes me glad I now drive an auto and can let the electronics decide which is the best gear to be in ;o)
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Sorry, to clear up the confusion.
The R75 gearbox for the 131Ps Diesel Turbo.
5th gear, 30mph/1000rpm
4th gear, 22mph/1000rpm
3rd gear, 16mph/1000rpm
2nd gear, 10mph/1000rpm
These are approximations, 5th is the most accurate.
Overtaking a car and caravan at 40mph, car in top. 1300rpm.
The 131PS CDT has a peak torque band of about 1750 - 3250rpm. The turbo really comes in at 2000.
So at 40mph to hit the peak torque, 4th gear, 40mph, 1800rpm
In the band, apply foot on throttle and lift off.
But at 65mph - revs in 4th = 3000rpm almost at the end of peak torque
So in 5th, 65mph is 2100rpm.
It's complicated and it requires a bit more planning that mirror-signal-maneouvre and boot it in a petrol car.
And as an ex auto driver, this was never a problem, any of it, autos are by far the easier way to drive a car.
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Incidentally, I was always told and am still always told you should sit in the highest gear possible for driving. The only exception was an ADI who I had as a passenger, they advocated a lower gear sometimes but only in traffic. He called it 'one less thing to worry about'
I agree with the 1st gear mentality, pull away, anything more than 5mph into 2nd.
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When I changed from petrol to diesel in my Golf TDI, I found it was easy to stall the car. When approaching a junction/roundabout with a petrol engine you could get close to it before dipping the clutch, but with the diesel leaving it too long meant the engine began to jump and verge on stalling. I assume that this is because of the diesel being a compression engine, I now find the diesel easier to drive (less gear changes) but I had to change my style of driving.
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What is really happening is that you are hitting the governor on the engine, and it trys to push you on to keep the engine speed up, whilst you are trying to slow it down (if you try this in 5th, it occurs around 25mph in most diesels!). You'd be pretty unlikely to stall it - you'd give up on the brake pedal first!Early down change, or declutching required to maintain smooth process.
RichardW
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"I was always told and am still always told you should sit in the highest gear possible for driving"
Ohmigod! Told by who?
(that being almost the exact opposite of what I teach)
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>Ohmigod! Told by who?
Exactly! Where does the peak torque occur? Usually 2,000 rpm in a diesel engine. Conveniently this also equates to the lowest specific fuel consumption (say kg fuel/kW power produced). So, it's best to try and stick to 2000 rpm as much as possible. Conveniently in my cars this equates to 30 in 3rd, 40 in 4th, and 50 in 5th - makes it easy to stick to speed limits. This also means you are right on the power to accelerate when needs be, and have all the flexibility you need.
I drove a petrol Focus in Holland last week - the first petrol car I have driven for about 30,000 miles - stalled it 3 times before I got it out of the carpark, and then couldn't understand why it wouldn't go up slip roads etc, until I realised I need to be 2 gears lower than in my TD to get it into the power band. Give me the diesl any day!
RichardW
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"So, it's best to try and stick to 2000 rpm as much as possible. Conveniently in my cars this equates to 30 in 3rd, 40 in 4th, and 50 in 5th - makes it easy to stick to speed limits.
So, it's best to try and stick to 2000 rpm as much as possible. This also means you are right on the power to accelerate when needs be, and have all the flexibility you need."
Vunderbar! Someone who understands!
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Would driving in the peak torque area in a petrol car produce the lowest specific fuel consumption even if ( for the sake of argument) peak torque occurred at 4000 rpm? I would imagine there is more of a balancing act with a petrol car as the peak torque figures are higher up or is that just not the case and the peak torque rule always applies?
teabelly
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"autos are by far the easier way to drive a car."
Agreed. Also by far the safest for the "old men" who think that revs are terrble and 30 in 5th is somehow "good".
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I have recently found that it is near impossible to stall my 306DTurbo, even in traffic jams i can let go of everything and it just keeps on going, the revs drop to around 850rpm but its still fairly smooth. I know there is an anti-stall speed but never really knew what it was for! I assume this?
Also, forgive my ignorance but why is the best fuel consumption at 2000rpm instead of lower, and why is 1000rpm not excellent? Not starting an argument i just dont understand that!
However if its best to hold 2000rpm that does me fine as the cars like a rocket when accelerating from there!
Thanks in advance for explaining this
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Also, forgive my ignorance but why is the best fuel consumption at 2000rpm instead of lower, and why is 1000rpm not excellent?
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Lots of things govern fuel consumption but a very important one is that engines are most efficient at the speed which produces maximum torque, and this typically occurs around 2000 rpm in car diesel engines, never at 1000 rpm for instance.
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"..what other gear do you suggest for 4mph?"
Well, for the little time I actually spend at 4mph, the clutch serves nicely (and before you ask, the last clutch I replaced was on my Wartburg in 1980). I can do 7-8 mph in second without it, which is slow enough for trundling around a carpack, surely? As it happens, I don't think second gears are any higher now than in days of yore, since we now have at least five ratios and wider powerbands - with petrol, anyway...
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"I can do 7-8 mph in second . .which is slow enough for trundling around a carpack, surely?"
Nope. Not when the limit is 4mph.
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"Not when the limit is 4mph."
I can't say I've met one of those, but how would you know you're obeying it? Most speedometers aren't calibrated below 10mph!
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