Diesel vs Petrol

Smiiithy

In short:
Does anybody know the rough figure in terms of mileage a person would need to do in order to make diesel more economical than petrol? I know there are many factors including MPG, maintenance costs etc which are affected by which car is chosen but I'm trying to work out a rough guideline in my head.


The full story:
At the moment I'm driving a 2002 1.5 dCi Clio and am getting just under 60MPG which I am more than happy with. At the moment I do around 20K miles a year, costing around £1,700. I figure the average petrol might cost me an extra £1,000 a year.

My girlfriend has just applied for her provisional and will be starting driving lessons in early 2010. I expect that if she was driving her own car (hopefully this will happen in 2010) I might cut my mileage by up to 9K meaning that a petrol would be a completely viable option and would effectively be costing me no more fuel than I'm paying at the moment. Servicing cost isn't a huge concern since my mechanic is a good friend and labour normally comes free or in return for a few cans of John Smiths.

I'm looking for a change in car. I can't afford to insure anything over insurance group 15 due to my age. My Clio has been quite unreliable and I want something that's going to be fun, not cost me a fortune to run and insure and won’t break down all the time. I have no need for a massive car as I have no kids/dogs and would only need enough space to fit my decoying gear in and I'm willing to spend up to £4K.

Diesel or petrol?

Hintza

Probably worth keeping an open mind. If you were buying new I think with reduced mileage etc petrol would probably just about swing it.

Modern Diesel cars tend to be a bit more complicated and can get quite expensive if they go wrong.

I'm very impressed you get 60mpg in your Clio so you must be driving it well (I'd be booting the hell out of it )

ukjoel

12-15k a year. Below that petrol, above that diesel.

However depends on age of car your buying, is it new or used, how long your keeping it for, size of engine and car, and type of driving, and even on local petrol v diesel prices.

Also depends on whats out there on the day and where the deal is?

Alan_M_2

Sometimes the purchase cost of the equivalent petrol model can be so much less that it would take an enourmous difference in mileage to recoup the difference (if you intend to own a vehicle and run it into the ground).

There's just too many variables to give a specific mileage. However given what you expect to drive, the fact you have no company car tax issues and you're buying second hand, I'd not worry about it too much and buy what you want and hope it's reliable.

In so much as a Petrol Clio that does 30mpg is going to cost less than a Diesel Clio that does 60mpg if the Diesel is forever breaking down and requiring expensive repairs.

If the budget difference is £1000 per annum I'd be more inclined to buy cheap and reliable with moderate running costs. Which probably means buying something Japanese. Toyota, Nissan Honda etc.

michaelro

ukjoel wrote: »

12-15k a year. Below that petrol, above that diesel.

These sort of figures are always banded about, but I don't understand them for used cars.

At present petrol is roughly the same cost as diesel, Servicing costs aren't too disimilar and any extra costs, you'll likely save in Insurance and Tax every year.

I was under the impression that if you're doing short distances all the time, petrol is better (still not ideal for the car) but if your journey is longer diesel is a good bet.

I do 125 miles a week to and from work, however this is almost all motorway so a diesel would be fine for me despite doing less than 10k a year.

thescouselander

Alan_M wrote: »

Sometimes the purchase cost of the equivalent petrol model can be so much less that it would take an enourmous difference in mileage to recoup the difference (if you intend to own a vehicle and run it into the ground).

There's just too many variables to give a specific mileage. However given what you expect to drive, the fact you have no company car tax issues and you're buying second hand, I'd not worry about it too much and buy what you want and hope it's reliable.

In so much as a Petrol Clio that does 30mpg is going to cost less than a Diesel Clio that does 60mpg if the Diesel is forever breaking down and requiring expensive repairs.

If the budget difference is £1000 per annum I'd be more inclined to buy cheap and reliable with moderate running costs. Which probably means buying something Japanese. Toyota, Nissan Honda etc.

I think the OP would be pretty unlucky to only get 30 mpg from the petrol clio - I get better than that in my 3L BMW!

nomoneytoday

I heard that the break even point could be as high as 25,000 miles a year.

On the plus side for diesels, driving in Europe is about 30% cheaper, and exhausts don't rust as easily

AdrianHi

It's a very difficult question to answer and the answer has changed since diesel came down in price to be around the same as petrol - for certain mileage ranges.
The answer depends on the individual car, mileage, kind of driving you do - diesels suffer bigger MPG penalties from best with short trips around town.
For smaller cars the size of a Clio it's harder to justify diesel on price alone, if your mileage is going to drop by 9000 a year I suspect a petrol will be as good or may be better on costs. It might be best to make your decision based on what you would prefer driving and the quality of used cars you find in the market regrdless of fuel type.

sebdangerfield

nomoneytoday wrote: »

I heard that the break even point could be as high as 25,000 miles a year.

On the plus side for diesels, driving in Europe is about 30% cheaper, and exhausts don't rust as easily

Why is a diseasel cheaper in Europe?

DaveMacD

Possibly because most other governments don't charge in excess of 70% in tax and duties....

ahillsy

As has been said by others, and despite other posts, there is no magic mileage number at which you should get a diesel over a petrol. It's a common misconception that diesels are only for people who drive over x miles a year.

I used to do ~18k year and made the switch from a petrol to diesel as it was right for my circumstances. For the past couple of years, I've been doing about 8K a year and still the diesel works well for me.

There are pros and cos each way:
- petrol variants of a certain model are generally cheaper than their diesel counterparts
- the diesel variants are generally a few insurance groups lower though and have lower tax band
- diesel gives better MPG. Even on short journeys, my experience is that the gap between MPG compared to petrol may narrow, but it's still better

My stance on the "diesel v petrol" debate is that you shouldn't only consider a diesel if you're doing high mileage - still consider if you're doing low mileage. The big caveat with some modern diesels is if they come with a DPF, which can make them unsuitable for certain types of driving - they have to go through a regeneration process at high temp to burn off collected soot. This regeneration cannot occur if you're just always doing short, stop-start journeys and it can lead to a costly replacement if you don't go and boot it down a motorway/A-road for 10-15 minutes. So, if you do look at a diesel with a DPF, you should be thinking about this. It's *the* reason I'm switching to a petrol for my next car as the diesel version would have caused me problems.