Thank you for explaining, i will end this topic now.
All this time, i was dumb enough to use Weight as the force for X and the Z axis 
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It works but now i have a problem, how do i limit the maxspeed? The speed is literally infinite.
I’m gonna be honest with you, I’m not sure. I’ve always used BodyVelocity and more simplistic designs for my vehicles.
You might have to code it to detect when a certain speed is reached using Magnitude on AssemblyLinearVelocity and then set the Force to 0.
It depends on how your script is structured, but what you can do is create a function that check the car’s velocity (part.Velocity.Magnitude), and if it’s greater than the maximum speed, set the force to 0/disable the force, otherwise keep the engine speed/re-enable the force. Then, connect that to RunService.Stepped so that it performs that check every physics step.
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