Normally we would say yes a higher
capacity car burns more fuel. that sounds logical.But do consider the driving
styles which would vary. one thing about smaller capacity cars is that, the engines are
actually working much harder, so in a sense, they would actually burn more petrol to
produce the same amount of bhp as a larger capacity engine. but then, cars with larger
capacity engines tend to be bigger, and heavier, henceforth, that is why they may have to burn more fuel, to get more power to move that extra mass.