This tach is a huge step beyond basic memory tachs that simply record the highest RPM. It records the RPM 10 times/second, all the way around the track, to be played back for you in the pits. See all the highs, the lows, and everything in between for multiple laps, the entire race if you want. You can see what the RPM was at any point on the track - the middle of the corner, the exit, halfway down the back straight, etc. See if you lost traction (RPM spikes slightly) or if the motor was falling off at high RPM (rate of climb slows). And when you just need a traditional Memory Tach it does that too. Stepper Motor design gives you precision accuracy and reliable performance week after week. This Data Logging Tach is like a movie rather than just a snapshot by a traditional Memory Tach.
SMi™ Stepper motor techometers use a small electric motor to drive the pointer. It is more precise than the more common 'aircore' instruments whose accuracy can be affected by the windings. Many professional race teams - NASCAR™, etc. – are switching to this style of tach for the improved accuracy and response (see the in-car TV cameras).