The price of fuel is only ONE component of running costs.

The overall cost per mile should be determinative for the budget-conscious. That takes into account durability, build quality, frequency of repairs, costs of parts, insurance premiums, and other things, such as interest on car loans and depreciation.

True, the cost of fuel is a wild variable and can't be predicted, and it is likely the trend will only be in one direction (and that is up!) but it is only one factor.

Another is safety. Buying a really safe car, that will protect you in an accident, like a Mercedes Benz or a Volvo, should matter, also.

The cost of medical care, or crippling or fatal injuries that occurred because you were trying to save money on fuel by buying a car that was made of paper mache makes a pretty convincing case to stay with Mercedes Benz, gas or diesel.

But every time the price of fuel rises, the sales of the little sardine can/good mpg vehicles spikes, too. I have rented some of those little tiny cars, and they scare me. In a bad wreck there is no doubt you could get killed, maimed, or paralyzed from being in one of them. Not worth it to me.

__________________
1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...

1995 E 420, 170k "The Red Plum" (sold)

2015 BMW 535i xdrive awd Stage 1 DINAN, 6k, <----364 hp

1967 Mercury Cougar, 49k

2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive (sold)