[wireties]

FYI, the motors can be +/- 10% off the published power curves. Simply sending the same values to the Talon/Victor/Jaguars will rarely make the robot drive perfectly straight. If you have encoders, feed them to the PID controller class to implement a velocity servo. The wheels will reach the same velocity eventually but might drive a little crooked while accelerating because one side accelerates faster than the other. You can compensate with 'P' constants.

Some teams add accelerometers and gyros feedback and help to drive straight and execute precise turns.

HTH