755 Kilograms and 69 horsepower, topspeed: 129 km/h

Hi,
I made a little 1983 volkswagen golf with a 1300cc engine producing 69.1 horsepower. It weighs 755 KG and it has 5-speed gearbox. the top speed is 129 km/h.
I'd say the top speed should at least be around 150 km/h so is this just the way the game calculates or am I doing something not entirely right?
Suggestions?
I made a little 1983 volkswagen golf with a 1300cc engine producing 69.1 horsepower. It weighs 755 KG and it has 5-speed gearbox. the top speed is 129 km/h.
I'd say the top speed should at least be around 150 km/h so is this just the way the game calculates or am I doing something not entirely right?
Suggestions?
