question Diesel or Petrol

[S80]

Without a doubt they were more reliable.....but were talking about longevity here

Anything can be kept going if you keep spending on it - a bit like 'Trigger's Broom'

 

[PeterCLK]

How many miles do the diesel engines in lorries clock up before they are retired?
(Assume non have petrol)

 

[GeeAy]

My pal bought a Fiesta 1.6D in 1985. No Turbo, no sound proofing under the bonnet. Made 4.5 BHP at 1250RPM. - He picked it up from the dealer and drove it onto the car park at RAF Locking, pleased as punch. Winds his window down and some wag says... Two 99's and a choc-ice please.. ;-)

 

[richyba]

It has to be diesel, we have an old 410d here which did 350k miles on tour work in real hostile conditions (the Burren for those of you that know Ireland). It has never had injectors or any heavy work other than the dual mass flywheel went. The vehicle is so good we have spent far too much converting it into a camper, it flew through test as such (smoke very low) it uses virtually no oil, starts in a flash from freezing and just keeps plodding away, couldn't imagine a petrol being here to tell the tale! :lol:

By the way expecting great things from my smelly and slow coupe to!

 

[st4]

Modern petrols now come with turbos, direct injection. The new breed of modern petrol engine may not be as simple as Malcolm suggests

 

[S500 Pete]

A big petrol engine without turbo etc can run for ever with very little stress and will probably outlast the expensive electronic toys that most modern cars have. It is these that will eventually make the car beyond economic repair.

But maybe I am biased

 

[S80]

One significant factor in longevity - whatever the fuel - is the degree of 'mechanical sympathy' present in the driver(s).

Red-lining a cold engine in 1st, harsh late braking, savage clutch use, speed bump abuse etc. are witnessed all too frequently :neutral:

 

[hawk20]

Used to be said as a rule of thumb that diesels do 300k and petrols 100k but both have got better due to synthetic oils.

Have to look size for size. Five litre petrols rev slowly at cruising speed but very few have engines that size. Most petrol engines rev far higher than most diesels, most of the time. And most petrols wear out more quickly than most diesels.

I have seen numerous Mercedes diesels with over 500k miles on the original engine. I have seen no such petrol engines.

 

[whitenemesis]

Used to be said as a rule of thumb that diesels do 300k and petrols 100k but both have got better due to synthetic oils.

Have to look size for size. Five litre petrols rev slowly at cruising speed but very few have engines that size. Most petrol engines rev far higher than most diesels, most of the time. And most petrols wear out more quickly than most diesels.

I have seen numerous Mercedes diesels with over 500k miles on the original engine. I have seen no such petrol engines.

Perhaps these stats have a lot to do with use of the vehicles? The diesel are probably workhorses, taxis and the like. The big engined petrols will be limos, or high performance variants, weekend toys..

 

[Ricardo_e220]

The problem i see with modern diesels is as mentioned by someone else is the turbo and electronic wizardry involved. We bought one of my old company cars I'd had from new the current shape volvo s40 2005 model, it was in phenomenal condition after 6 years and didn't show half of its 140k miles, the engine was like a train kept on pulling, the problem was its value, £2500 due to the miles, something wierd started happening with the ecu and kept going into limp, problem was no one could pin point the issue and it could have been one of the 4 (yes 4 )computers on board...each one over £600.... Second hand ones not ossicle due to coding issues

We got shot to replace with the a class p'exing it

Similar happened to my mums c270 - depends where your break point is on a car

Petrols seem to be cheaper to keep running for longer, but tend to do lower annuals miles, hence why IMO there are more on autotrader over 10 years old - most will now be being sold on eBay instead I think.

Oh and I have seen lorries with over 600000 miles after just a few years, we had one merc actros where I worked and it ran European trips non stop, it had 900,000 kms on it after just 4 years!

 

[st4]

Perhaps these stats have a lot to do with use of the vehicles? The diesel are probably workhorses, taxis and the like. The big engined petrols will be limos, or high performance variants, weekend toys..

And to take this post on a step further, why is that.

Diesels tend to be better for the uses you site as they are more economical and the basic mechanicals last better.

Petrols rev harder, tend to make more peak power and until a decade ago, had such a major refinement advantage that they were suited to luxury cars.

Now, I feel both are fine for an everyday car. If I had a weekend toy, it would probably be something like a Lotus Seven, Elise, small light thing that would suit a revvy engine and not much torque.

For a jobbing car that covers all bases from touring, commuting, long distance travel etc a diesel is fine. So would a petrol varient if it were cheaper to buy to offset the fuel usage.....

 

[Ricardo_e220]

And to take this post on a step further, why is that.

Diesels tend to be better for the uses you site as they are more economical and the basic mechanicals last better.

Petrols rev harder, tend to make more peak power and until a decade ago, had such a major refinement advantage that they were suited to luxury cars.

Now, I feel both are fine for an everyday car. If I had a weekend toy, it would probably be something like a Lotus Seven, Elise, small light thing that would suit a revvy engine and not much torque.

For a jobbing car that covers all bases from touring, commuting, long distance travel etc a diesel is fine. So would a petrol varient if it were cheaper to buy to offset the fuel usage.....

Agree completely I have an s2 lotus Elise type 49 special edition, and even with a weedy 120bhp 1.8k rover k series engine it will take its featherlight 750kgs to 60 in around 5 secs... Little B roads are its playground, it's simply made and simple to fix and revs to 8k .....woooooooooooooo

 

[Cardinal Biggles]

Just a quick search on autotrader.co.uk for cars over 10 years old reveals:

3854 diesel
21873 petrol

which just goes to prove that ten years ago people were buying petrols, rather than the crap, slow, dirty, underpowered and antiquated diesels on sale then.

 

[Blobcat]

12 years ago the 3226 IL6 CDi was launched in the UK, a very fine engine indeed

I've also noticed a great deal of 911's with well over 100K miles, I belive that more than 75% of all 911's are still on the road and none of them have been diesel (so far...)

 

[Ricardo_e220]

which just goes to prove that ten years ago people were buying petrols, rather than the crap, slow, dirty, underpowered and antiquated diesels on sale then.

That's a bit generalisation, 10 years ago I was running round in a golf gttdi with 150bhp, my mum had a c270cdi at the time... If it were 20 years then I'd agree, her 2.5d c class non turbo was dog slow till it was wound up, 1.9d pugs and vws etc went for ever but more glacial than graceful lol

 

[st4]

I belive that more than 75% of all 911's are still on the road and none of them have been diesel (so far...)

911's are collectable and desirable. Thats why generations of them become cherished classic cars and are kept on the road regardless of cost.

I'd love a 911.


DSC_0880 by stephentaylor4@hotmail.com, on Flickr

 

[Neil H]

My thought may be a little simplistic but the diesel reliability tradition was formed 20 years ago when they were technically simple and built strongly. The new gen diesel engines are as, if not more complex than their petrol comparitors. I think the legacy view is now void, you are more likely to have electrical issues than mechanical ones these days..

Which have the better ECU/control systems, petrol or diesel?!

 

[st4]

Niel,

Depends, some petrols can be unreliable, some very reliable, same with diesels.

With direct injection, DMFs, turbo charging hitting petrol cars en mass, their relative mechanical simplicty trump card may well be coming to an end.

But they offer other advantages, better refinement, lower mass (I for example would love to try a C250CGi and see how it feels on the road compared to my diesel) and in some cases higher peak power

 

[Neil H]

Id much rather have a petrol than a diesel but today I drove to work and back in a car that will do 6 seconds 0-60 and it returned 44mpg, that would be unbelieviable 10 years ago!
Would still rather have a CLS500 though!

 

[st4]

The new diesels, particularly the 6pot ones are so quiet and refined I am not so sure I would have one, not in a big luxury car.

I'd save petrol power for something small and light....