LCP

Unless the car computer's mistaken, the tachometer reads optimistic. Using the a/c display to access the OBD codes while driving at steady RPMs I observed the following:

1. 3000 (steady) on the tach equalled 2960 (it rounds to the nearest 40RPM) on the OBD.
2. 4000 (steady) on the tach equalled 3920 on the OBD.
3. 5000 (steady) on the tach equalled 4920 on the OBD.
4. 6000 (steady) on the tach equalled 5880-5920 on the OBD (varied).
5. 71xx on the tach (at the APR chip's rev limiter) equalled 7000-7040 on the OBD.

I also observed that at the rev limiter in second gear, the display was also telling me I was doing 104 km/hr, which equates to 64.5MPH, about 1MPH faster than I thought the S4 would have gone at 7000RPMs. I don't know how this error plays out at higher speeds where I suspected the speedometer becomes optimistic as well.