Jump to content

Petrol vs Diesel


hooli
 Share

Recommended Posts

A bit of a weird one so thought I would ask the question on here and see what opinion is...which is more expensive to run, petrol or diesel?

Reason I ask is we are trying to replace my wife’s car so went to a car supermarket yesterday so we could walk around and my wife could see all the cars in one place and decide what she likes, doesn’t like, fits the prams etc.

The sales guy obviously wanted a fair bit of info before we went out to look at cars and I ran through the list of makes, models, age etc. I said preferably diesel and he questioned me on why. I said better economy, lower car tax etc. He was adamant that unless you do a lot of miles, diesel is actually more expensive. When I asked him for a bit more info, he got very vague and couldn’t really answer.

Now I know diesel is about 4p per litre more expensive than petrol so presumably that offsets the higher mileage per gallon, car tax will be a bit less on a diesel as emissions are less. New car prices are higher for diesels, servicing costs...

Not too worried about penny pinching, I was more curious than anything.

As a side note, one of the cars we looked at was the Vauxhall Zafira - the thing is like a tardis inside!

Link to comment
Share on other sites

  • Replies 50
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

It depends on the purchase price of the car.

If you're spending the same amount of capital whether you're getting a petrol or diesel, then that one's parked. It's often the biggest argument when buying a new car. You're likely to get a slightly younger petrol than diesel for the same money (6-12 months depending on the car make and model).

Assuming you're looking at a more modern car (say up to 5 years old) then the servicing costs will be the same for both, so really it comes down to fuel. OK so diesel is more expensive (about 5p a litre?). If you're doing 10k miles a year in a petrol that does 35mpg, then that'll set you back (10,000/35) = 286 gallons = 1,298 litres = £1,623 a year in petrol. Same in a diesel doing 45mpg then that'll set you back (10,000/45) = 222 gallons = 1,008 litres = £1,310 a year in diesel.

So it's "only" £313 a year difference.

* all rough figures and I'm sure someone's got a fancy spreadsheet to work all this stuff out ;)

Link to comment
Share on other sites

How many miles do you average in a year?

As a rough guide, over 30k then diesel, under 20k petrol, between 20 & 30k it's fairly even.

This is odd as i do 13000 mile a year. I used to own a petrol car now have a deisel but i have not noticed an increase in costs. I have actually saved money. I use less fuel as my mpg has gone from 30mpg to 50. It cost that bit more at the pump but i can do nearly 200 miles more on a tank than previously. The tax is £100 cheaper as well so even though i do not do the miles you have stated i have saved money. Obviously i am not saying you are wrong just that i do not fit the example.

Yes i do drive like an old lady most of the time but i still have moments of fun. I think it will depend on your daly use. If your usual drive is a five min job that means the car never gets a chance to warm up then yes petrol is a better way to go in my opinion. If the your usual drive is a long run then diesel would be the way i go. As i only buy used cars i do not have the worry of the inflated cost of the different types. Used cars seem to be fairly similar although slightly more for the diesel.

As said though this is only from my experience and not being a technical person with all the facts i'm sure i am probably wrong in general it just that i seem to be going against the grain here.

Link to comment
Share on other sites

Cheers Mook, that was my understanding too so was wondering if I had missed something obvious.

The cars we are looking at are about 5 years old and although the diesel ones are between £500 and £700 more, with the better MPG and car tax being a bit lower it would all even out in a year or so.

Can you tell I am on a long and not very interesting conference call at the moment :)

Link to comment
Share on other sites

I think it used to be more clear cut than now.

When deisels used to have short service intervals it meant you needed to do the miles to offset that cost.

Now I believe they're around the same as for a petrol car?

Edited by Scotty
Link to comment
Share on other sites

Obviously it depends what 2 cars you are comparing, for example if you used to have a Subaru impreza petrol, an now you have a polo tdi, at any mileage the polo is going to be cheaper.

You have to compare equivalent models, buying used the gap is narrower, but most people are still better off in a petrol.

Link to comment
Share on other sites

Welcome Hooli, looks like you'll fit right in here! :)

After little more than 3 weeks, I can say with reasonable certainty that my diesel Legacy is cheaper to run than any petrol Subaru... :P

The waters have been muddied in recent times with the technological improvements of both diesel and petrol engines, and I think they get muddied even further by the driving preferences of people these days, now that diesels are more powerful and more refined. I think a lot of drivers now tend to prefer the torquier (is that a new word? :P) characteristics of a diesel to its petrol equivalent.

Link to comment
Share on other sites

Just to throw a curveball in the mix - I look at it in terms of performance vs economy vs big bill vs smaller bill. Allow me to explain. I have a 2.5tdi a6 and a 1.8 petrol a4. Now people go on about the 2.5 being rubbish economy but, it's about the same, if not slightly better than the 1.8 petrol but the a6 is much much more powerful and a far smoother ride. The only petrol equivalent would be the 2.7 which is going to cost at least double that of the 2.5tdi.

So yes, doing lowish miles may work out cheaper in a petrol, but you can get a much more powerful, smoother ride for very little in way of price increase if you opt for the diesel engine.

Link to comment
Share on other sites

I have spoken to the service guys here and have had a bit of luck. Comparing a 4 year old Espace petrol 2.0 litre and a 4 year old diesel 1.9 for anual mileage service there is not much in it. The Petrol needs servicing every 18000 mile where as the diesel every 12000.

The cost of the servicing in at the first service sees the petrol being £10 more exspensive to service but the second year it is £101.51 more exspensive for 6000 more miles on the clock. The 72000 mile service is where the sting is however as the diesel rises to £981.93 where as the petrol is at £1089.14 quite a jump from the regular £200- £350 price range.

This is just a guide obviously as it is an estemate and i can't give you exact figures for a general car.

Hope that gives you an idea though.

Link to comment
Share on other sites

You have to compare equivalent models, buying used the gap is narrower, but most people are still better off in a petrol.

There's the crucial point... you have to be comparing like for like.

Compare similarly-performing new diesel and petrol models, and the diesel will often be more expensive to buy. So you have a fixed extra cost and a variable saving, and it is only worth it if you maximise the saving - i.e. high mileage.

Compare nearly-new, and either the price premium will still be there, or you will be looking at a younger petrol car. Same difference, therefore,

Compare two ancient cars, and their economy figures will depend more on their condition than on what they allegedly did when they were new.

So, the answer is that in general, diesel suits the high-milers, but if you're buying s/h then you need to consider the two that you're actually choosing from - which might well be different models/years/engines/colour* and so on.

*red is both the fastest and the best mpg

Link to comment
Share on other sites

Comparing apples to apples - take the case of someone buying a new Mini.

They can buy a new Mini Cooper petrol for £14780 which is rated at 52.3 mpg or buy a new Mini Cooper D at £16060 which is rated at 74.3mpg. The Mini Cooper D costs £0 in road tax and would probably be slightly cheaper to insure than the Mini Cooper. The Mini Cooper costs £90 per year in road tax. Residual value is likely to be better on the Cooper D.

Fuel for 15k miles in each works at todays average prices (which are £1.28.4per litre for Unleaded and £1.33.3 per litre for diesel)to £ 1224.40 for the Mini Cooper D and £ 1675.48 for the Mini Cooper. Servicing costs/intervals are the same for either under the first 3/5 years under Mini TLC. The initial purchase price for the Mini Cooper D is £1280 higher. So overall for any ownership period over 28 months - the Cooper D works out as the better buy financially.:grin:

Link to comment
Share on other sites

I am just comparing my experience of driving to the Ring on a tank of juice and being able to do a few laps also.

90 litre tank - £100 quid to fill up, have 20 litres left when I got to the Hotel etc.

Friends Golf 55 litre tank (or there abouts) had to fill up again to get to the hotel. Yes the mileage and tank sizing are the same, when adding up 2 tank loads and comparing against the M but outlay is in minds sake is more for me compared to the Golf. I averaged about 31MPG and got about 450 miles to my tank, where as he only got 300 to his tank, just saying that tank sizing can effect what might seem to be a cheaper car to run if your filling it up everytime.

Link to comment
Share on other sites

I am just comparing my experience of driving to the Ring on a tank of juice and being able to do a few laps also.

90 litre tank - £100 quid to fill up, have 20 litres left when I got to the Hotel etc.

Friends Golf 55 litre tank (or there abouts) had to fill up again to get to the hotel. Yes the mileage and tank sizing are the same, when adding up 2 tank loads and comparing against the M but outlay is in minds sake is more for me compared to the Golf. I averaged about 31MPG and got about 450 miles to my tank, where as he only got 300 to his tank, just saying that tank sizing can effect what might seem to be a cheaper car to run if your filling it up everytime.

I have never, ever understood the whole "miles to the tank" thing. Whether your car has a 35 litre tank or a 60 litre tank, it'll still do the same mpg.

Tell you what, next time you fill up, instead of putting 60 (or whatever) litres in, only stick 30 in and see how many fewer mpg you get :P

Link to comment
Share on other sites

Larger tank = longer range but more fuel = more weight therefore less mpg?

Ahh, but larger tank also = not having to drive to the petrol station as often, therefore reducing your overall mileage and hence getting more useful miles to your tank and effectively increasing the mpg and the miles per tank!

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share


×
×
  • Create New...