I’m quite good at keeping financial records. For anyone interested, this is what my last 2 cars cost me per mile.

Both were Astra G 1.6 8v estates. Both were purchased with low mileage, at less than a year old, from car supermarkets. I did about 44,000 miles in each.

I used the first for 4 years, the 2nd for 6.

The first was sold as an accident write-off to an insurance company, the 2nd was sold privately.
Cost of depreciation of the 1st was 11p/mile, the 2nd was 12.57p/mile.

The first averaged 40.1mpg and cost 9p/mile for fuel, the second did 38.6mpg and cost 12p/mile.

The first cost 8p/mile for everything else, the 2nd cost 12p/mile.

Total cost of the 1st was 27.5p/mile, the 2nd was 36.5p/mile.

One of the surprises for me was to realise how little the fuel cost, compared to everything else. It seems to me that, if you take someone somewhere and they offer to “help” with the petrol, then they’re not being very generous at all. They ought to be paying for all of it, at least.