540 versus 550
What‘s the difference between a 540 motor and a 550 motor? Which is best?
The difference between a 540 and a 550 motor is the length of the motor's cylindrical case, or “can.” Both motors are the same diameter, but a 550 motor is about a centimeter longer than a 540. That extra length accommodates a longer armature and magnets (if it’s a brushed motor) or rotor and stator (if it’s a brushless motor). Either way, the longer 550 armature or stator will have more wire wrapped around it than the 540 version, and the 550’s magnets or stator will be longer than the 540’s and, thus, have a stronger magnetic field. A 550 motor will spin at lower rpm than an otherwise identical 540 but will have more torque. 540 motors are usually used in lightweight 1/10-scale vehicles, like touring cars, 2WD buggies, and stadium trucks. Heavier vehicles, like short-course and monster trucks, often use a 550 motor because they need the extra torque to get them moving with authority.