That's because diesel carries 2p more tax a litre than petrol

Ultra-low sulphur fuels of both types have exactly the same duty level since april 1st , 2001 , and that's been the only type you can actually buy at the pumps since then

At the end of the day there isn't a single right answer for everyone.

Exactly, I'm happy with petrol but I still think the milage pay off for diesel is well under 20k mile p.a.

When I did the sums for petrol/diesel when I bought my car, diesel would have been cheaper to run even at 12-13k mile p.a. In the end I plumped for petrol as I thought that it was a better for long term ownership - compared to DPF/Cambelt requirements of the diesels I was looking at.

I'm also thinking that the 40 mpg from a petrol is at the decidedly good end of economy for a such a car and the 50mpg quite poor for a diesel.

Certainly on an octavia sized car you can get 40mpg from a petrol engine but you have to try hard to get it. Drive a diesel in a similar fashion and you'll get more than 50.

Looking at the Fiat Bravo (my probable next car) the 120bhp 1.4T petrol claims 42mpg and the 120bhp 1.6TDI claims 57.

There's a big £1500 difference in list price which would take 49k miles to recoup fully (using £1.50 and £1.65 fuel costs) , but assuming half of that is reclaimed on resale then that's just 24.5k miles which I do in less than a year.

Swap to the 105bhp 1.6 ECO TDI and you'll be in profit after 12k miles (assuming the same fuel prices and retaining 50% of the price difference on trade in)

Diesel cars 'not such a good buy' | This is Money

Should I still buy a diesel car? | This is Money

Research by the AA has showed that high fuel prices now mean that a new diesel car buyer would have to drive 43,000 miles to beat the cost of owning a petrol car.

This is based on the higher cost of a new diesel car and the cost of diesel at the pump rising faster than petrol. However, depreciation means that if you decide to buy a second hand car the difference between buying a diesel and petrol vehicle is less pronounced.

Well, petrol cars have far fewer needs for a fuel filter change than a diesel and other than sparkplugs & HT leads (which if half decent should last for ages) I cannot think of any additional costs for a petrol service over a diesel?

Turbo diesels tend to munch through tyres, and seem to wear suspension parts out vastly quicker than petrol equivalents. Big factors in choosing my "budget" motor is that it couldn't have a DMF or a turbo Historically diesels have had much shorter service and belt change intervals than petrol equivalents (although that seems to have changed in recent years).

I think the unpredictability of fuel prices etc means that you would be as well to choose an engine based on your preference of power delivery characteristics etc.

Historically diesels have had much shorter service and belt change intervals than petrol equivalents (although that seems to have changed in recent years).

This is what I'm wondering about. Will this affect the longevity of modern diesels?

If you look at my car just to confuse things.

I get about 40mpg combined.

Now the equivelent petrol with similar power would be averaging about 20mpg when driven at the same level of thrashing.

Therefore diesel is better for me....... 300bhp+ m3 bmws cant get away from me and I would like to see them do 40+mpg

MK I Octy Dervs variable service up to 30k miles

MK I Octy Petrol variable service up to 20k miles.

No idea what the mileage is on the cambelts for a petrol VAG car but the 2.0 TDI is 80k miles or 4 years and the petrol one is probably 60-80k and 4 years also.

Modern petrol engines all have a turbo which up their efficiency and plenty of them have DMF's and lambda probes and this and that...

Basically all modern cars are too complicated.

A lot depends on how you will use the car and how long you will keep it. If you are an average buyer looking to use the car for 18,000 miles of average social domestic and pleasure use, you will need to consider owning the diesel for nearly three years before it pays for itself.

However, if you are say a minicab driver, you will cover the distance much more quickly, potentially doing more urban and stop / start work, so should see payback in less than 12 months. There is more though. Petrol engines tend to have a shorter service life than diesels, so a cabby could be keeping the car for 3 or more years covering up to 200,000 miles. Here the stop / start work and urban use will improve the diesel advantage. Also, the petrol will be starting to be marginal for things like compression ratio by this mileage.

As a driving instructor, I spend a fair bit of the day doing manoeuvres and lots of round the houses type of work. For this a petrol car is far worse than a diesel. I get at the very worst, 35mpg from a day with the Fabia vRS. This with aircon on and all day on slow urban roads with lots of manoeuvres. I had a petrol Corsa 1.0 that did similar average with no aircon for general driving, where the Fabia would be doing 45+.

So it all depends on usage. "Civilian" drivers would be often best to get back to their petrol cars. For us commercial users, this would reduce demand for diesel meaning possibly cheaper fuel for us.

Some strange aberrations skew this though. How about a diesel Phaeton?

Chris

This is what I'm wondering about. Will this affect the longevity of modern diesels?

Newer oils have got much better at keeping solids suspended and lubricating around them. My Fabia is still running strong at 114,000 miles and shows no signs of lazy starting (an early sign of compression loss in diesels). Oil consumption is the same as it has always been too.

Chris

Turbo diesels tend to munch through tyres, and seem to wear suspension parts out vastly quicker than petrol equivalents. Big factors in choosing my "budget" motor is that it couldn't have a DMF or a turbo Historically diesels have had much shorter service and belt change intervals than petrol equivalents (although that seems to have changed in recent years).

I think the unpredictability of fuel prices etc means that you would be as well to choose an engine based on your preference of power delivery characteristics etc.

modern engines change... my diesel has no issues with DMF (VAG only?!) and 18,000 mile service intervals, and a 90,000 mile cam-belt change.... (I haven't even changed a set of brake pads (every brake component original) and I'm approaching 50,000 miles....

same for others suggesting a modern petrol (small turbo) like the fiat 120bhp 1.4 turbo will be hard on fuel and immesions.. it isn't , its the same emissions as the diesel, and 40+mpg really is acheivable.....

so things are evening out......

edit: Tom, agree with your last paragraph...

I'm also thinking that the 40 mpg from a petrol is at the decidedly good end of economy for a such a car and the 50mpg quite poor for a diesel.

often get 40-45mpg with my 2.0 petrol.

often get 40-45mpg with my 2.0 petrol.

as my above post, the 150bhp fsi is a new engine is it not? they are getting better....

... my diesel has no issues with DMF (VAG only?!) ....

same for others suggesting a modern petrol (small turbo) like the fiat 120bhp 1.4 turbo will be hard on fuel and immesions.. it isn't , its the same emissions as the diesel, and 40+mpg really is acheivable.....

so things are evening out......

Re the DMF issues, it would seem that all manufacturers are having issues with them. I have seen them go bad on VAG and Ford.

It will be interesting to see how the new generation of small high specific output engines fare in longevity terms. As for fuel economy, I reckon they will be good unless idling, traffic crawling. This is where the diesel seems to win.

Chris

Re the DMF issues, it would seem that all manufacturers are having issues with them. I have seen them go bad on VAG and Ford.

It will be interesting to see how the new generation of small high specific output engines fare in longevity terms. As for fuel economy, I reckon they will be good unless idling, traffic crawling. This is where the diesel seems to win.

Chris

re: dmf I wouldn't say all.... fiat haven't... and wasn't the ford issue with the galaxy that had the VAG engine?

but then its not really comparable if you have a stop/start like the petrol honda civic hybrid.... and lots of people are introducing this, like BMW, so the advantage is lost.... things change so quickly.....

but then its not really comparable if you have a stop/start like the petrol honda civic hybrid.... and lots of people are introducing this, so the advantage is lost.... things change so quickly.....

The key advantage of the diesel in low speed running is the smaller amount of fuel it uses when running. I have run a couple of short term teaching cars with petrol engines and the difference is very marked. The petrol car drink substantially more in slower situations, manouevring, pottering around side roads etc.

Remember stop / start is being fitted to diesels now as well.

Still reckon diesel is better for commercial drivers.

Chris

Newer oils have got much better at keeping solids suspended and lubricating around them. My Fabia is still running strong at 114,000 miles and shows no signs of lazy starting (an early sign of compression loss in diesels). Oil consumption is the same as it has always been too.

Chris

Is your Fabia on the usual fixed servicing 10k oil changes? The VAG fixed servicing regime seems short compared to other servicing regimes.

Turbo diesels tend to munch through tyres, and seem to wear suspension parts out vastly quicker than petrol equivalents. Big factors in choosing my "budget" motor is that it couldn't have a DMF or a turbo Historically diesels have had much shorter service and belt change intervals than petrol equivalents (although that seems to have changed in recent years).

I think the unpredictability of fuel prices etc means that you would be as well to choose an engine based on your preference of power delivery characteristics etc.

Tom , no offense , but anyone who follows your advice on budget motoring needs their head examining

often get 40-45mpg with my 2.0 petrol.

On a whole tankful , or a single slow run down a motorway?

Bring on the petrol trucks then eh.... Nonsense

Hmm, I've just part ex'd my Mk1 Octy RS for a Mk4 Golf PD130, because I struggle to see 300 miles from a tank. Surely pound for pound I'm goin to see more mileage from the Golf?

Another thing that swung it for me was RFL, currently it's £210 a year I think, soon to go up to £260 then £270? The Golf is around £120 a year. I know that might not seem like a massive exspense for most, but every little helps!

re: dmf I wouldn't say all.... fiat haven't... and wasn't the ford issue with the galaxy that had the VAG engine?

but then its not really comparable if you have a stop/start like the petrol honda civic hybrid.... and lots of people are introducing this, like BMW, so the advantage is lost.... things change so quickly.....

Fiat/GM share some engines and IIRC GM have been having big problems with them. I know a owner of the ugliest car in the world that had theirs go too, but not to the same extent of problem as VAG appear to be having.

I really struggle to get mid 30's mpg wise out of a 1.2 fabia, driving it fairly easy and just trying to keep to 60-65 mph on a motorway.

Tom , no offense , but anyone who follows your advice on budget motoring needs their head examining

Says the man that is nearing the end of his warranty on his brand new Octavia. The 2.0PD is clearly the "holy grail" of fuel efficiency and reliability! I like to change my cars often, get over it. I've never said changing cars often makes good financial sense, it obviously doesn't.

As always there is going to be a different "answer" for every individual and their preferences and circumstances. What Chris says about diesels being more viable for the commercial driver is probably correct, but for example if you do a lot of short journeys where the engine is started from cold, then the petrol could well be more frugal.

I do think its a little bit sad when people choose a car for financial reasons alone. Desire has to come into it somewhere surely :confused:.

I do think its a little bit sad when people choose a car for financial reasons alone. Desire has to come into it somewhere surely :confused:.

Come on now, you cant tell me you Desired a mundaneo :P

Says the man that is nearing the end of his warranty on his brand new Octavia. The 2.0PD is clearly the "holy grail" of fuel efficiency and reliability! I like to change my cars often, get over it. I've never said changing cars often makes good financial sense, it obviously doesn't.

£300 one off for a luxury warranty, including wear and tear for 13 months from warranty direct doesn't sound too bad for me. It covers all the common parts and a few more.

As always there is going to be a different "answer" for every individual and their preferences and circumstances. What Chris says about diesels being more viable for the commercial driver is probably correct, but for example if you do a lot of short journeys where the engine is started from cold, then the petrol could well be more frugal.

You are aware that when cold, a petrol car runs rich but a derv always runs lean aren't you? Dervs are more efficient when warm than cold, but petrols follow the same trait.

I do think its a little bit sad when people choose a car for financial reasons alone. Desire has to come into it somewhere surely :confused:.

Desire is not an option when you can't afford it surely? A lot of the current problems we see with the worlds financial system is due to this effect.

People didn't ask themselves could they afford it, but then the banks didn't either which is even more worrying.

Personally I'm more than happy for everyone to go back to petrol, means I'll get my derv cheaper.