How can you work out a vehicles fuel consumption?

Question

how can you work out (approximately) a vehicles fuel consumption simply going by its specifications? (eg. 2.0 litre 5 speed manual. etc)

Answer 1

There is no way without running it and testing.  The tuning has a lot to do with is as well as the weight of the car and even wind resistance.  Too many things that cant just be turned into number to calculate.  Even manufacturers estimates are very optimistic as they just run them on rollers with a little resistance but that will never compare to real road conditions.

Answer 2

The only way to do it, absent filling your gas tank and seeing how long you can go on a single tank of gas, is to go to this web site.  That's the simplest way.

Answer 3

A long complicated math equation that involves lots of variables like;

Horse power of engine, natural aspiration or boosted, air pressure in and quality of the tires, quality of oil, clean air filter, how heavy ones Right foot is, humidity levels, etc. . .

hope my answer helps.