Cars: What is cheaper to run between petrol and diesel?

Current petrol price where I live is 117.9p per litre

Current diesel price where I live is 129.9p per litre

Based on these figures - what would you rather have?

1. A petrol car that returned 40mpg

2. A diesel car that returned 70mpg

10 points await the person who can be bothered to show me some calculations.

Many thanks

13 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    117.9 per litre x 4.55 = £5.56 per gallon

    £5.56 / 40mpg

    £0.24 per mile

    129.9 per litre x 4,55 = £5.91 per gallon

    £5.91 / 70mpg

    £0.08 per mile

    AND the winner is Diesel !

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  • 1 decade ago

    I recently changed my car and I made the same consideration, before making my purchase.

    Previous car - 1,600cc diesel, 5-speed manual. Average 45mpg, 3 years old.

    Current car - 2,400cc petrol, 4-speed automatic. 30mpg, 3 months old.

    You'd think it would be cut-and-dried wouldn't you?

    However, based on my annual mileage (7,000) and the very important fact that diesel costs on average 55p per gallon MORE than petrol, my new car will only be around £3.50 per week more expensive to run, than the old one. Pretty good, considering it's almost a litre bigger in capacity and an auto as well

    Of course, if I'd gone for a smaller capacity motor, I'd actually be financially BETTER off with a petrol engined car...

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  • Mark D
    Lv 4
    1 decade ago

    The biggest consideration is your annual mileage:

    Taking into account that on average a petrol car is £1500 cheaper than its diesel equivalent, that extra 30mpg is worth £1500 / 12p (per litre difference) = 12500l = 2750gallons = 82500miles! So the diesel car will only start paying for itself once you've done that many miles - so if you're doing 30,000 miles a year as a rep, and change your car every 3 years, the diesel makes sense, otherwise stick with the petrol.

    Of course, these figures don't take into account variations in depreciation, tax, insurance or personal taste (do you want that diesel drone? Given the choice I'd get my V8 petrol Range Rover out of the shed, but poverty's keeping it there!)

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  • ?
    Lv 7
    1 decade ago

    Depends whether you are looking at like for like. Last year I had a 2 litre petrol peugeot 406 and I averaged 34mpg. I now have a 2 litre Peugeot 406hdi diesel and average just over 46mpg. A diesel engine will, in general, last a lot longer than a petrol one, but will cost more initially. Often if you do not do a high mileage the diesel advantage is not as much as you would imagine. There are other factors though - one of the most frequent causes of break downs is problems with the ignition system. A diesel does not have one!

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  • GOD
    Lv 6
    1 decade ago

    Sorry to jump in on your question but I must give a comment to shouty dad, LPG may actually be cheaper to run but if you have to have the car converted first at a cost of £1500, you will probably have sold the car before you have reached the point of making a saving, so unless you have a car that is already converted, it is not going to save you money.

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  • 1 decade ago

    Where I live Unleaded is a lot cheaper than diesel, with unleaded coming in at 89.9p per litre and diesel coming in at 137.9p per litre

    So in my case Unleaded is cheaper

    Hope I helped, Granty.

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  • 1 decade ago

    I have a diesel and it's falling apart, as you can't go fast anymore due to all the speed cameras there is no need for us to all rely on this antiquated way of using transport.

    If we all used ELECTRIC cars for the towns & public transport to go long distance we'd save a lot of money in fuel!!!!!!

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  • Anonymous
    1 decade ago

    using those figures the diesel is the most fuel efficient.......however the diesel car will have cost more to buy and servicing costs are more expensive so they probaly work out very similar over a 12 month period

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  • 1 decade ago

    It depends on at least the initial purchase price of the vehicles, the difference in taxation on the two vehicles, and how long you'll be driving each before we can figure out which one makes more financial sense.

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  • 1 decade ago

    what calculations do u want 2+2=4

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