A shift light is a warning lamp fitted to vehicles in order to indicate to the driver that maximum RPM has almost been reached. Ideally a shift lamp will illuminate at the engine speed beyond that which delivers the maximum BHP such that the BHP before and after shifting is the same. Accelerating the engine beyond this point is not conducive to rapid acceleration. In use a shift light allows the driver to judge the exact point that a gear change should be carried out without having to glance down at the tachometer. This also increases safety for the driver by keeping his focus on the track at all times.