Diesel or petrol - msm
Firstly, sorry if this debate has already taken place but I did a search here on diesel etc, but didn't get the kind of info I was after.

Basically I'm thinking of replacing my petrol car with say a BMW diesel, 525td or 530d. Almost all my driving is around town, mainly short journeys. I'll average about 10k miles per year. The reason I was looking at diesel is the fear of getting aweful fuel eco from a petrol engine.

I was wondering if a diesel would be a better bet for me over the same size petrol engine. Being quite clueless about the comparions I was hoping someone could point out what else I should be considering or maybe someone has a link to a site that will help me make a decision.

Do diesels require services more often? Does the cost of maintenance outweigh any benefit in fuel consumption?

Just trying to get some answers to common questions I guess. Thx in advance.

Diesel or petrol - Dynamic Dave
A quick search found this:-


Which search option did you use? The "Forum Search" to the right where you log in/out is better than the "site search" at the top of the page.
Diesel or petrol - Dizzy {P}

We have two search systems, one of which is pretty useless whilst the other is superb. Cannot the 'Site Search' be taken out so as to avoid confusion for new users?
Diesel or petrol - Dynamic Dave
Dizzy, I'll look into it.

Diesel or petrol - Dan J
Suggestion. Depending if it's worth the cost to change it, keep the forum search and allow the "Site search" to search everything but. Otherwise as Dizzy says, the latter is a bit of a waste of time...
Diesel or petrol - Andrew-T
My diesel experience is with Peugeots, so take my comments specifically or generally, as you wish.

Fuel: 20-30% more to the gallon. Diesel consumption less affected by lots of short trips. Annual saving at 10K/year ~£160.

Servicing: Diesel needs more frequent oil/filter changes, but has glow plugs instead of spark plugs (which need changing more often). Diesel exhausts often last 10 years, a lot longer than for a petrol.

Depreciation: hard to compare, but (like for like) diesel costs more, but you get more on resale.

Driving: diesel engine loads the front of the car more heavily. 21st-century diesels are not far behind petrols in performance, and cruise very well on motorways at only 2500rpm.; better pull at low engine speed.
Diesel or petrol - Malcolm_L
Economy in town will be far better with a diesel, diesels don't have chokes, with direct injection diesels glowplugs are only required in very cold conditins (<-0C).

It will probably cost more initially - which will offset to a large degree any savings you make.

Maintenance isn't as much of a problem as it used to be - modern diesels are going 12k between services and more.

More subjectively, the different driving characteristics of petrol and diesel may influence you more than any monetary issues.

Some folk like the modern turbo diesels, some don't - definitely worth comparing diesel v petrol.
Diesel or petrol - Robin the Technician
My experience is across the board and includes commercial vehicles too. The diesel engine is now a high power well refined beast. The benefits are that when you've started it up, its cylinders are openating at optimum temperature. This means no need for excess fuel as with a petrol and its choke. With no excess fuel, reduced cylinder wear = longer life engine. A diesel's 'burn' is more efficient too thus also reducing bore wear. Direct Lines life expectancy of a Peugeot 406 diesel is 450.000 miles as confirmed to me by one of their engineers. This would probably be the life of the car. On the up side too is servicing- no plugs, leads, cap, rotor arm etc, so sevicing costs usually cost less cos' there's less to change.
I have owned 3 montego diesels all of which outlived the car body, a rover 115sd which was unrefined and noisy but returned 50+ mpg. My current cat is a Pug 406 est diesel and it is a superb,comfortable,quiet ride with an excellent mpg for a large car considering I do a lot of short journeys.
If you've not tried one, go do so. You will be surprised by the lack of noise and the willing performance.

These are the views of Robin the Technician with 35 years in the trade. I fix, therefore I am...
Diesel or petrol - Vansboy
Robin, did they give an estimation on life of the petrol? I posted a thought on the V6 as opposed to HDi, last week? (Not doing the miles I used to!)

Regarding your Montego comments, my Meastro van clicked over to 310,000 miles last week! The engine was changed on 270,000 miles - with a turbo,complete with power steering , much appreciated, from a Montego, which ALREADY had 110,000 on it!! Still retirns 50 +mpg!!

Diesel or petrol - Ivor E Tower
Go for the diesel. A change of job and circumstances happened to me in the mid 1990's. Lots of long motorway journeys and a 12 mile cross-country commute to work changed to a 5-mile town crawl to work with very few journeys being out of town. Rover 820 petrol gave me 34 to 38 mpg on motorways etc, this became 20-25mpg in town after we moved house. Changed it for a Renault Scenic diesel and got 48mpg irrespective of town driving or motorways. Added bonus is longer exhaust life, as for short journeys a petrol car is running rich (on choke, manual or electronic) which also does the engine internals no good either and is more polluting. A diesel runs at its best whether hot or cold, long or short journeys. Although I also do a low annual mileage, on balance I considered a diesel was a better bet even though it cost more to buy initially. Personally I also find a diesel's low-speed power and torque advantage makes it a better drive in town - less gear changing, more relaxing etc.
Diesel or petrol - Sooty Tailpipes
I must say, I bought a diesel to save money, but am now a convert.
I would never buy a petrol again (all things equal)
Coupled to an automatic, they really shine through due to all that extra torque. I have driven my BMW enginned Omega Auto and a BMW 320d auto, both are excellent to drive and refined. None of that sluggish lag when setting off you would get with a manual.
Diesel or petrol - Dizzy {P}
I bought my first diesel this year, though I've driven many before. It is a 2003 Rover 75 manual with the 131ps engine and it replaced a 1992 BMW 525i automatic. The Rover is a pleasure to drive, though not quite as pleasurable as the BMW which was initially far more expensive, but I wish I had specified an automatic gearbox!

There's no real engine lag with the Rover but having to change from 1st to 2nd at quite a low speed (15-20 mph) and then 2nd/3rd, 3rd/4th, means that you can't quickly and smoothly shoot out from a sliproad or side-road onto a busy main road and get straight up to the general traffic speed. Also, having to keep changing gear in slow-moving traffic situations is irritating, even with the low-speed torque of the diesel engine.

It seems that automatic boxes have quite an impact on the fuel economy of diesel engines, as much as 8 mpg in the case of the Rover, and I regret dismissing them for this reason, especially since my annual mileage is relatively low and thus fuel economy is not too important. In any case they will still do a lot better than the equivalent petrol cars (auto or manual).

Would I buy diesel again? Probably "yes" but I would take both petrol and diesel engined versions for a fair trial, perhaps by renting, before coming to a decision. Some diesels 'do it' for me, others don't. Whatever, it would almost certainly be an automatic next time.
Diesel or petrol - Andrew-T
Dizzy - I presume you have tried starting from standstill in second instead of first?
Diesel or petrol - Dizzy {P}

Yes, I sometimes start off in second. However this gear is really just a touch too high for moving away and the clutch needs to be eased in quite steadily, so little is gained.

It's not a big problem but just takes the edge off an otherwise excellent engine/transmission power train. No doubt Rover has tried to cater for all, including caravan towing and driving in the Alps, whereas I tow nothing and my short-haul runs tend to be in the Cambridgeshire fens!
Diesel or petrol - Robin the Technician
Sorry, no- The reason I got the info waslast Christmas time i was driving through a small flood very steadily when large van man came theother way at circa 40mph+ and completely flooded mine and several other motors. The wash flooded my engine and bent a rod. The insurance did pay up for repairs minus the mileage already clocked up. This was calculated against the life expectancy of the engine. Thats how i got to know!!! I would think that the max life expectancy of a petrol to be 200k.
The Montego/Maestro's had excellent running gear sadly let down by the bodywork made from recycled Lada's. My Montego Estate, despite me spending a whole weekend waxoyling it fell to bits after 8 years. I even looked round for a kit car that could have taken the running gear but to no avail. Shame really as it was a treat to drive and for me was comfortable.

These are the views of Robin the Technician with 35 years in the trade. I fix, therefore I am...
Diesel or petrol - NARU
Basically I'm thinking of replacing my petrol car with say a
BMW diesel, 525td or 530d.

Of the two, I'd recommend the 530d if you can afford it.
Diesel or petrol - msm
Thanks folks, excellent insights there. I didn't know half of what I know now, so am feeling a lot more positive and comfortable with the idea of replacing my petrol for a diesel car.

Now, to convince the missus that the change is a must :)


Diesel or petrol - maniac5
The BMW diesels are that good you could probably get the wife in, start it up and you wouldn't notice the diesel noise...

I've got a rover 220SDi - Very nippy and still i'm getting excellent feul economy.
Diesel or petrol - 8 ball
like you I'm about to replace my current vehicle with (either a Merc 270d or 320d or) a BMW 530d. Nice to be able to have that choice. However, don't take any chances. Do what I've done: Having test-driven the BMW I borrowed a Merc 320d for 48 hours from the local dealer and later this week will do the same for the BMW. Like maniac5 says, you would hardly know they're diesels. But holy mackerel they don't half GO!!
happy hunting
8 ball
Diesel or petrol - NormanB
The BMW diesels are that good you could probably get the wife in, start it up and you wouldn't notice the diesel noise...

...Lol .... and is that a reflection of the quiteness of the diesel or the incessant chattering noise from the wife!!!
Diesel or petrol - The Flying Dutchman
seems you are convinced then - good! I've driven diesel for quite a few years now and like others I would never go back to petrol for all the various reasons listed above.
If you have trouble convincing the missus come back here with here concerns and we'll help you relay them :-)
Diesel or petrol - msm
Flying Dutchman: LOL! Thx ;)
Yep, got my petrol car up for sale and hunting for a diesel as we speak. I just don't understand why I've been ignoring diesels up until now.

8 Ball: It's great that you get to drive in the car for 2 days before making your mind up. I had no idea dealers would even consider something like that. Let us know which one you prefer.

Diesel or petrol - PhilW
I've been driving Citroen diesels for 16 years now and have always found them to be utterly reliable and economical. Two of the engines did over 150k before being sold on and the only "work" done on them was cambelts and oil changes. They always did 45 or more to the gallon but performance of the normally aspirated ones was only adequate. The turbos were better and the latest HDis I think are wonderful. Smooth, quiet, economical and good performance - the cruising at 30 mph per 1000 revs is very relaxed and acceleration is excellent unless you are into "boy racing" (though the number of boy racers in 306 turbos suggests otherwise!).
The BMW/Merc engines are reputed to be even better - I'd love to try one if so -they must be real crackers. Take your wife for a drive in a modern diesel - she won't realise it is diesel unless you tell her except that you don't visit the pumps as often. (And if you ever drive on the continent you will fill up at about 60p a litre!)
Diesel or petrol - Malcolm_L
I lent my Passat PD130 to a colleague as he needed an estate, he can't understand how a 'diesel' with less bhp than his car 'had so much more go'.

I'll put him out of his misery on Monday - torque rules ok!

My only concern is that if the shift from petrol to diesel continues, the government will be forced to up taxation to claw back lost revenue.
Diesel or petrol - hillman
Do a cost/benefit analysis, not too difficult.
1. What is the additional cost of the diesel engine (£1000.00 - £1250.00 ?).
2. Calculate the difference in cost of fuel for petrol and diesel over 10,000 miles.
How many years would it take for the fuel cost savings to equal the higher cost of the engine ?
Has anyone a feel for this ?
Diesel or petrol - 8 ball
In the case of the BMW it is £5. Yes, £5. I can't quite remember whether the diesel is £5 MORE or £5 LESS than the petrol. End of need to calculate mpg's, I guess.
8 ball
Diesel or petrol - Dizzy {P}
The initial cost difference depends on the models you are looking at. For me, the choice was Rover 2.5 V6 petrol or 2.0 4-cyl diesel, both 'Connoisseurs'. The diesel was not only less to buy but is far more economical on fuel, with cheaper insurance and road tax. What clinched the diesel for me was its petrol-like refinement combined with excellent torque delivery.

Diesel or petrol - Big Cat
I remember seeing a program a few years ago that was saying that the increasing demand for diesel will result in a lot of unsold (and hence cheap) petrol. The reason behind this theory was that you cannot produce all diesel from a barrel of crude oil, a certain amount of petrol has to be refined off first. If this is true then you could end up with a situation where diesel gets more expensive at the same time petrol gets cheaper!
Diesel or petrol - Malcolm_L
I don't doubt that the demand for diesel will increase, however petrol will still be a valuable fuel whether for cars or any other resource requiring energy.

Who'd have thought 20 years ago that natural gas would be used to power gas turbines in power stations?

Diesel or petrol - daveyjp
As shown on Top Gear last night it's the torque of the diesel that's the real difference. Even Clarkson (who hates diesels) was impressed at how the Lupo 1.4 TDi readily accelerated from 50-70 mph in 5th, when the 1.6 GTi didn't - the diesel also cost £4 less in fuel than the GTi on one circuit of the M25. It was a refreshing change to see Top Gear do a realistic motoring report.
Diesel or petrol - Malcolm_L
Realistic motoring report, good to see something other than a 100k supercar being reported on.
Most major manufacturers are shifting the emphasis to diesels especially at executive level - which Jezza regards as lunacy.

Jezza being a tad bigoted doesn't worry me too much, the man having a following of thousands does!
Diesel or petrol - davemar
But you wouldn't attempt to go from 50-70mph in 5th with a 16v petrol engined car, particularly a GTi which is designed for a peakier performance. Doing it in 3rd gear you would blow away the diesel's time in 5th (the diesel is unlikely to be able to do it in 3rd gear). I can't remember the last time I drove a petrol car in top gear while doing 50mph, as you're below the powerband, and any flooring of the gas pedal will just result in labouring of the engine which isn't good for it's health.
Diesel or petrol - Malcolm_L
Agreed - the point is that the diesel can do it and it's useful performance without having to change down.
Rough equation is that diesels have twice their bhp in torque whilst petrol cars have about a 1-1 ratio.

Ultimately it comes down to personal preference, I like driving SWMBO'd MX5 but not for long distances, Passat wins everytime.
Diesel or petrol - Tony N
This will go round and round for ever I think. You can't argue that diesels give superior fuel consumption and modern diesels certainly make respectable power these days. However it depends what your after, to me nothing beats occasionly taking the nice, smooth 2.0l petrol engine in my Civic to 7k (something a diesel will never achive) whilst having the flexibilty to trundle around town at under 2k if needs be. It'll return a real world 40+mpg too if you drive it right. As I say, swings and roundabouts...
Diesel or petrol - hillman
One aspect is that of safety. Reading a recent Telegraph article I was reminded that if you pour a small quantity of diesel fuel into a baking tray, light a match and throw it in. The match will go out. Don't try this with petrol as you will probably blow up as you light the match.
That said, the incidence of fire in crashes is very small.
Diesel or petrol - peterb

Why is fuel economy so important to you?

If you're prepared to fork-out for a 530d and only do 10k per annum, does it really matter?
Diesel or petrol - AlanGowdy
I'm getting a bit wary of telling people how superior diesels are over petrol in the 'less-than-supercar' classes. If everybody starts buying them the government will get in on the act and alter the currently advantageous tax situation. SSShhhhh !!
Diesel or petrol - SR
One of the mags did a very good comparison recently (i.e. the last few weeks) of "equivalent" petrol and diesel versions of the same model, looking at the overall costs for a 3 year period. May be of interest.

If only I could remember which one and when - Autocar, What Car or Auto Express?

Will try to dig it out if no-one else gets there first.

Value my car