Fuel consumption in Mafia 1.

Besides the faster cars, of which I observed that they eat up a lot of gas (and of course that certain guzzling sled in some Freeride Extreme mission), was it normal for most vehicles ingame to like sip just a bit of juice? I just noticed that while some vehicles that I jacked only have the tank at half-full, it takes a long while for them to go half or empty.