In general how much higher are running costs on older cars?
Obviously a new car will have less things wrong with it so will need fewer repairs, and will be at it's peak effeciency.
If you do not count depreciation, how much more expensive is it to run and maintain a vechicle that is say 15-20years
hard question to answer. typically insurance will drop with an older car to a degree. some parts will go up though as it has less safety equipment.
fuel economy will eventually start to irreversibly drop as well, but when is hard to say.

Domestic car sales in October witnessed their steepest monthly decline in the past 10 years due to challenging demand environment, higher cost of ownership and running cost caused by inflation and increased fuel prices. Vishnu Mathur, director general
By Reporter Nine out of ten British motorists feel the cost of running a car is increasingly difficult to manage, a survey has revealed. Rocketing petrol and diesel costs have seen fuel duty reach a record high this year, with four in ten of
It's true, of course, that you can buy a much cheaper economical gasoline powered car, but over time, cheap running costs and minimal service needs for the MiEV, will make a big dent in the price premium you pay for buying an electric car at the outset
That seems like a reasonable proposition considering that the cost of running the car, at around Rs 0.5 per kilometer is almost a tenth of a petrol car's over Rs 4 per kilometer. There are some serious riders though. Most electric cars are powered by
We also wanted an economical car, one that would cost little to own and run over a lifetime at least as long as our old Civic's 18 years. The cost of 18 years' of gasoline is significant. For some cars, it's comparable to the initial cost of buying the
Running a car is a growing problem thanks to rising fuel costs say, nine out ...: By Daily Mail Reporter Nine ou...
Running a car is a growing problem thanks to rising fuel costs say, nine out ...: By Daily Mail Reporter Nine ou...
Cars burn little fuel per yr vs init upfront cost. OTOH industrial motors cost only fraction of ann operating costs.