Which is cheaper to run - petrol or diesel?

Baldytyke88

Its also a matter of where the electricity is coming from to charge the electric car. The cheapest would be your own solar/wind, then from your own domestic electricity supply and the most expensive would be public charging points.

born_again

WIAWSNB said:

Or, more precisely, by how much? Given, say, an 8k annual mileage.

I know diesel is significantly more economical, but also costs more at t'pump. Diesel engine services are dead simple and cheap - how much more will a petrol service be? 

(Not bothered about PDF and all that malarkey.)

I much prefer a diesel - torque, economics, reliability - but should really be open to petrol alternatives to keep my options as wide as possible. Eg, Mazda CX5 - 2 litre nat-asp petrol vs 2.2 diesel.

Thanks for thoughts and insights

Unless you know the MPG than you are just guessing.

All I can say is 13K miles has cost me £236 in electric charging at home.
If I paid a average of 60p for not charging at home £1957 for same miles. Easily done using Tesla chargers in fact local are sub 50p

WIAWSNB

Many thanks everyone.

Hmm, I'd assumed that petrol would be more costly to service than diesel, due to the plugs and stuff, but I've been corrected on that one - useful, thank you.

I'm not bovvered about PDF 'cos they've never caused us an issue (other than when my last car ran out of Eolys - sorted immediately afterwards.

My current 1.5HDi C3 Picasso never drops below a 50mpg average, regardless of what journeys it's on. Its predecessor - a C3 Pic with the 'same' engine - rarely dropped below 55 ave. I'll miss that, but hey. I'd also miss the easier torquey behaviour, but can live with both.

Hybrids and leccy are out of the Q at the mo' due to purchase cost and limited options - that'll most likely be our future car (even tho' I do have PV). (Quite tempted by a 2.5 PHEW Kuga I saw recently, tho'...)

WIAWSNB

facade said:

If you want Mazda, the most reliable engines are the Skyactive-G NA petrol. They also use TC auto gearboxes for extra reliability.

The diesels have a very poor reputation, most likely any fuel cost saving from a diesel will be more than offset by the repair bills!

Useful extra info - thank you. I'd happily go petrol & auto, especially now with what you've said. 

WIAWSNB

Mildly_Miffed said:

WIAWSNB said:

Or, more precisely, by how much? Given, say, an 8k annual mileage.

I know diesel is significantly more economical, but also costs more at t'pump. Diesel engine services are dead simple and cheap - how much more will a petrol service be? 

(Not bothered about PDF and all that malarkey.)

I much prefer a diesel - torque, economics, reliability - but should really be open to petrol alternatives to keep my options as wide as possible. Eg, Mazda CX5 - 2 litre nat-asp petrol vs 2.2 diesel.

It's impossible to say. It's entirely down to reliability - and if you're "not bothered about" DPF, I presume you're looking at cars at least 16yo, because DPFs became ubiquitous with Euro5 emissions in 2009 or so. Then add Adblue for almost all diesels under 10yo, Euro6 emissions. If you're looking pre-2017, then CO2 taxing is relevant.
There's not a lot of difference between a diesel and a petrol service these days, with ignition being computerised and plugs needing replacement every 100k miles or so.
The difference between the two fuels can only be a few pence per litre. I filled up yesterday with diesel at £1.399, unleaded was £1.359.
Let's work a ballpark 45mpg, so 10 miles per litre - 800 litres per year. You're talking about £32 difference on £1100 expenditure.
If you're talking about the difference between 40 mpg @ £1.36 and 50mpg @ £1.39, then you're looking at £1220/year for petrol vs £1010 for diesel. £200/year difference. It's a trivial difference, easily wiped out by one bill for maintenance or repair.

Good 'sums' - thanks.

I've never had a PDF problem - both my Citroens (2011 and 2015) have been faultless in this regard (and everything else 'engine').

MPG from both have been solidly mid-50s's, never falling below 50 ave. I know I couldn't bear a low-40's petrol return, which is what the petrol Kugas certainly suggest, and I'd weep openly if it fell into the 30's. Won't the 2L petrol CX5 be similarly poor? 

finbaar

Unless you have a very specific use for diesel then it's outclassed by petrol hybrids. I had 20 years of diesel only until my current car and I'm about to replace that with another hybrid. The hybrids have been cheaper to run, but looks away MSE members, I find the cost of doing 22k a year fairly trivial.

WIAWSNB

Hybrid appeals, certainly, but that's a future move. Too costly to buy and too few options at the mo'. 

user1977

I recent switched (back) from diesel to petrol and was surprised how frugal the petrol engine is, there seems to be little difference in mpg even for long motorway journeys. Perhaps a newer diesel engine would be even better but I wonder if generally there's less of an advantage in mpg than there used to be.

Johnmcl7

WIAWSNB said:

Mildly_Miffed said:

WIAWSNB said:

Or, more precisely, by how much? Given, say, an 8k annual mileage.

I know diesel is significantly more economical, but also costs more at t'pump. Diesel engine services are dead simple and cheap - how much more will a petrol service be? 

(Not bothered about PDF and all that malarkey.)

I much prefer a diesel - torque, economics, reliability - but should really be open to petrol alternatives to keep my options as wide as possible. Eg, Mazda CX5 - 2 litre nat-asp petrol vs 2.2 diesel.

It's impossible to say. It's entirely down to reliability - and if you're "not bothered about" DPF, I presume you're looking at cars at least 16yo, because DPFs became ubiquitous with Euro5 emissions in 2009 or so. Then add Adblue for almost all diesels under 10yo, Euro6 emissions. If you're looking pre-2017, then CO2 taxing is relevant.
There's not a lot of difference between a diesel and a petrol service these days, with ignition being computerised and plugs needing replacement every 100k miles or so.
The difference between the two fuels can only be a few pence per litre. I filled up yesterday with diesel at £1.399, unleaded was £1.359.
Let's work a ballpark 45mpg, so 10 miles per litre - 800 litres per year. You're talking about £32 difference on £1100 expenditure.
If you're talking about the difference between 40 mpg @ £1.36 and 50mpg @ £1.39, then you're looking at £1220/year for petrol vs £1010 for diesel. £200/year difference. It's a trivial difference, easily wiped out by one bill for maintenance or repair.

Good 'sums' - thanks.

I've never had a PDF problem - both my Citroens (2011 and 2015) have been faultless in this regard (and everything else 'engine').

MPG from both have been solidly mid-50s's, never falling below 50 ave. I know I couldn't bear a low-40's petrol return, which is what the petrol Kugas certainly suggest, and I'd weep openly if it fell into the 30's. Won't the 2L petrol CX5 be similarly poor? 

My Mum has the two litre 150bhp petrol engine in a CX-3 and the long term average is 38mpg, I have a Mazda6 2.5 which averages around 35mpg.  Initially it felt a bit of a shock after coming from a diesel however I don't find in practice it's that much different cost wise (as explained above) and the car is approaching 15 years old without a single issue with the engine.  I used to be a big fan of diesel engines but my last VW diesel engine had various EGR and DPF issues to the point I'd had enough and didn't do big miles to justify the hassle.  While diesels can run ok, there's just a lot more to go wrong these days.

I would be very cautious about buying a Mazda diesel since the previous ones had a terrible reputation, I don't know about the one the CX-5 uses.

WIAWSNB

user1977 said:

I recent switched (back) from diesel to petrol and was surprised how frugal the petrol engine is, there seems to be little difference in mpg even for long motorway journeys. Perhaps a newer diesel engine would be even better but I wonder if generally there's less of an advantage in mpg than there used to be.

Is your petrol the small-turbo'd-engine variety, typically 1.2 litre? I understand these can be pretty impressive.

The lump in the Mazda is a 2 litre wheezer...