I believe that most games work on x,y,z axis for rotation.
Rotation is rotation around the CofG not the centre of the car body (check this first!
I may be wrong for NFS)
x is pitch - 1650 in this case (imagine a stick shoved through the car side to side through the CofG) the car pivots around this when you transfer load forward and backwards (braking & accelerating)
y is yaw - 1750 in this case (the stick is vertical through the car now the car swivels around this point when looking down on it)
z is roll - 370
As Kazumi says the car isn't a box with equal mass distribution.
This link is very old, but probably still holds good it has an interia calculation buried within the weight distribution section, read it carefully and try and understand the calculations and you will understand interia.
Use the calculator and for example just change the mass of the engine - everything will change - car mass, CofG, and Inertia.
Then change mass of engine again and remove and equal amount of mass from somehwere else (maybe fuel) - different result again. They are all connected, but in complex ways.