Grand Theft Auto IV
Tank cars are found at the Firefly Projects Rail Yard along with several flatcars. At other locations around the map, they can be found rusted out with other abandoned rolling stock.
Grand Theft Auto V
Four different Tank cars can be found. The first is an orange car largely unique in design but with a somewhat European influence. This car can commonly be seen being pulled by freight trains.
The second is a black car based on the standard North American DOT-111 tank car. This car can be found as a static object in train yards and sidings.
The third is a white car identical in design to the black car but is instead painted white. This car can only be found as a static object in train yards.
The last is a rusty wrecked car reminiscent of the two previous cars but much older and slightly larger in appearance. It can be found as a static object along the abandoned rail line and rail yard in El Burro Heights and in scrapyards across San Andreas.