I dont know why, its not the motor, but my car isnt as speedy as the others. like when pressing forward with another chassis, it goes fast. but when pressing forward with this chassis, it doesnt have that pick up speed as with the other. but top end speed is almost there. its also older then my otheres. no hair in the gears, and motor has NO problem. is the battery getting old or something? its only 1 month old. mm.. i dont know, and i also have a 49mhz to trade for a 45mhz