Forums Forums Enthusiast Forums A - Z Autowirral Diesel v Petrol

I don't know much about cars at all, so any 'shop talk' will be lost on me and I won't know what you're saying but my question is, are diesel cars better on fuel consumption than petrol? According to the performance ratings it seems that you get a lot more mileage per gallon with diesel. Is it worth the extra cost per litre or not?

The short answer is, it depends.

* Diesels are more economical, but the fuel is more expensive than petrol.

* Diesel engines are more complex due to the emissions control equipment required = more expensive to fix when they go wrong

* Diesels are not suitable for short journeys (about-town driving)

There's loads of info online if you can be bothered to google.

Oh see,, I didn't know that they're more expensive to fix and nor did I know they are not as suitable for driving in town.
Thanks for the answer I'm glad I asked

In short... if you do a high annual mileage, then the sums indicate that it can be cheaper to run a diesel. For lower mileage/around town pottering, petrol is your better bet.

Years ago, diesel road fuel was on a par with petrol prices - even cheaper sometimes. Then of course diesels became popular. Cue for hike in taxes!

Someone with more knowledge than I might verify (or not) that diesel requires LESS refining than petrol - so why are we being taken to the cleaners in having to pay more for it ??

Sorry Elizabeth. Drifting away from your original question.

You're right that diesel needs less refining than petrol. Diesel is a fraction of crude oil very similar to heating oil. It's winter, demand for heating oil has rocketed, so the prices for heating oil and diesel have gone up. Supply and demand and all that...

Hybrid cars that run petrol/electric are currently the most realistic vehicle you can get for the best fuel consumption. As they are new, the capital cost is high so you'd need to think of the amount of money you'd want to spend and how long you want to keep the car.

I agree that diesel would be better if you did loads of long distance driving. Years ago I had to drive a diesel works car. It was not the knowing on doors that bothered me but the car. I am only 5'1" and I found the car heavy like driving a tank. Petrol suits my'Noddy'car as I mostly do town driving.Have found the Shell petrol station at Upton roundabout near Sainsbury's best for petrol. It seems to last far longer than buying it from Supermarkets.

Used both and prefer petrol as cheaper to maintain. Do mostly town driving now anyway. The petrol is still economical when I have to do a long trip as its only a 995cc engine, 20 quid road tax and about 70 to the gallon. Suits me sir.
When I had a Terrano I could watch the fuel gauge moving if I put my foot down on a motorway, scary.

Thanks for all the answers. It looks as though when I eventually return to UK, a petrol car would be a better bet as I wouldn't be doing a lot of mileage.

Whatever I do buy though I'll get more mileage per gallon than I do here in USA. I don't have a huge car here (series 3 BMW), but I only manage to get about 20-22 mpg and I drive on the highway most days, it's even worse around town

I assume you know that US gallons are smaller than UK gallons? Seriously. Petrol is no longer sold in gallons in the UK, although "mpg" is still commonly used.

To put some numbers in:
1 gallon UK = 1.2 gallon US
1 gallon UK = 4.546 litres

I'd disagree with the statement "Diesel engines are more complex due to the emissions control equipment required = more expensive to fix when they go wrong".

That only applies to *some* modern diesels.

For example, ones with smaller engines and lower power output don't necessarily have the dreaded Diesel Particulate Filter on them.

Older diesel engines are very simple, that's why you see so many Peugeot 306s and 406s with upwards of 160,000 miles on the clock still running smoothly and perfectly.

As for the price increase, the development of industry in China meant demand for diesel increased.

I think its important to also find the right car...

Ive had lots of cars over the years and get lots of different, new cars hired for me to travel for work.

Over the past 9 months Ive had a Prius - averaged 62mpg, a 2.0 Diesel Golf (GTD) 62mpg, 1.4 Petrol (Turbo Golf) 42mpg, 1.6 Petrol Astra 35mpg, 1.6 TDi Seat Leon, 52mpg and I currently have a 2.0 TDi Golf which just did 69mpg on a 450mile round trip.

The Prius only really worked well when stuck in slow moving traffic, and would take a long time to in fuel saving to get the initial purchase cost worth while. The Astra, was the worst on fuel, despite being a 1.6, but I looked up it weight, and its a hefty 1600kgs - the same as a 5 series BMW! The 2.0 Golfs are better on a run that the smaller 1.6 diesel Seat...

If you want to drag up and down the motorways, id suggest a diesel, congested city driving, maybe a Prius (I guess these make more sense for company drivers as they will also get tax relief) and for normal town driving a small petrol car...

Or course you also need to weigh up the initial purchase cost too and how long it will take to for the car make itself worth while.

And some diesels can run on vegetable oil (if you pay the excess duty)

Up to a certain amount (2,500 litres per year last time I checked) you don't have to pay duty on it.

Vehicle does smell like a doughnut van though