diesel versus petrol, when does it become pointless

[Apache]

Take, for example a petrol engined car that does 31.5 miles to the gallon and a diesel engined car that does 41.5 miles to the gallon, factor in the difference in price of, say 5p.....how the hell do you work out the cost per mile and the point where it is cheaper to go for petrol?

[busta]

[jamei303]

Start with the cost of purchase.

Work out how many miles you do a year then work out the cost per mile in fuel for each car. Add any difference in annual insurance/maintenance etc. Multiply this by how many years you plan to own the car and add to the purchase cost.

Also check the sale value of the car at the age you intend to sell, subtract this then compare.

[1878]

"diesel versus petrol, when does it become pointless"

Normally by the end of the second page, sometimes sooner.

[theaxe]

If we assume that petrol ( from here) is 134.69ppl and diesel is 140.67ppl.

Per gallon that's (using 4.55 litres/gallon) £6.13 per gallon of petrol and £6.40 per gallon of diesel.

So using your mpg figures that's 19.4 pence per mile for the petrol and 15.4 pence per mile for the diesel.

Still working on the break-even point.

[Dave^]

Try this...


http://www.thisismoney.co.uk/money/cars/article-16...

[PJ S]

If you're not doing 15K per annum, with the vast majority of the time spent sitting at a steady speed, then petrol is just as efficient.

[Rocksteadyeddie]

PJ S said:

If you're not doing 15K per annum, with the vast majority of the time spent sitting at a steady speed, then petrol is just as efficient.

Au contraire. IME you will get significantly better fuel economy on the motorway from a diesel. Round town, stop start, and when cold there's not a lot in it.

[twazzock]

I think that's what he was saying!

[R300will]

Rocksteadyeddie said:

PJ S said:

If you're not doing 15K per annum, with the vast majority of the time spent sitting at a steady speed, then petrol is just as efficient.

Au contraire. IME you will get significantly better fuel economy on the motorway from a diesel. Round town, stop start, and when cold there's not a lot in it.

I would thnk round town, stop start, with a cold engine the petrol would come out a bit better off as it will warm up quicker and it doesn't have a DPF to get clogged up?

[Rocksteadyeddie]

Rocksteadyeddie said:

PJ S said:

If you're not doing 15K per annum, with the vast majority of the time spent sitting at a steady speed, then petrol is just as efficient.

Au contraire. IME you will get significantly better fuel economy on the motorway from a diesel. Round town, stop start, and when cold there's not a lot in it.

Yeah like wot 'e said.

It's well past my bedtime... evidently.

[pah250]

Apache said:

diesel versus petrol, when does it become pointless

As soon as you turn the key! They sound like your starting an old tracker!

[Nick3point2]

I think you need to learn to use excel.

[anonymous-user]

Work on 18K a year for a break even point.

However this assumes that you are using main daler servicing and adhere to the schedules rather than letting things break, in which case diesel will be cheaper for longer but you run the risk of very expensive things failing and effectively restoring the balance.

[frosted]

R300will said:

I would thnk round town, stop start, with a cold engine the petrol would come out a bit better off as it will warm up quicker and it doesn't have a DPF to get clogged up?

Meh , the other day I had to go hammer smith at 5:30 in the eving , obviously ques of many many miles when my dpf had enough of driving at 2mph all day and decided it can't regenerate so the light came on . By that time I had enough and at Kensington decided to turn back home on the lovely a3212 which was a car park . 2hrs later I got home , parked up at which point my sister took my car to go shopping , light was still on , then in the morning I went to work at 2mph and came back at 2mph in total probably drove around 3-4 hrs with the light on , in the evening I decided its time to get rid of the light do jumped in the car went to wandsworth and jumped in the a3 at 5mph . By the time I got to staples corner ( 5 miles ) of driving at 50 mph the light was gone .

Moral of the story is , dpfs are nowhere near as bad as you heard

My car with 95k on the clock , lives in perfect harmony in London traffic

[IainZ]

I've just replaced a 1.8T Passat with a 5 yr old BMW320D. In general use the Passat would average about 30mpg, the BMW averages over 40, on the motorway while the Passat would do maybe 35mpg, the BMW will do closer to 50. The BMW costs 130 quid for a basic service, the VW more than that (and it has cambelts to change every 4 years at £300+ which the BMW doesn't). The BMW may have cost a bit more to buy than the petrol equivalent but then its resale value will also be higher. On 10K miles a year at 31 vs 40mpg respectively the difference in fuel costs will be around £375.

[PJ S]

pah250 said:

Apache said:

diesel versus petrol, when does it become pointless

As soon as you turn the key! They sound like your starting an old tracker!

Just where exactly do you put the key in a Bloodhound?

[BlueMR2]

IainZ said:

I've just replaced a 1.8T Passat with a 5 yr old BMW320D. In general use the Passat would average about 30mpg, the BMW averages over 40, on the motorway while the Passat would do maybe 35mpg, the BMW will do closer to 50. The BMW costs 130 quid for a basic service, the VW more than that (and it has cambelts to change every 4 years at £300+ which the BMW doesn't). The BMW may have cost a bit more to buy than the petrol equivalent but then its resale value will also be higher. On 10K miles a year at 31 vs 40mpg respectively the difference in fuel costs will be around £375.

It'll suck when a diesel only part breaks and costs you around £1k but you'll get that back in 3 years, providing nothing else breaks.

[IainZ]

BlueMR2 said:

t'll suck when a diesel only part breaks and costs you around £1k but you'll get that back in 3 years, providing nothing else breaks.

That would indeed "suck" but the risk of it happening seems low enough to take the gamble

[BlueMR2]

I've heard of so many problems with the components having such small tolerances and needing computer setup.

Or people putting in petrol instead of diesel and just flushing it through which must shorten the life of the pump that i'll just stick with petrol.

People seem to be learning about the cost of diesel based failures and with all the other systems they have to put in to meet emission targets i think that petrols are going to start a comeback. Unfortunately, they will start putting the same crap in petrols and they'll start to fail just as much.

Shame the government concentrates on co2. Its like the climate equivalent of speed cameras.