One unique feature of the late model E46 M3 and E39 M5 is the tachometer-temperature warning lights.  These light are designed to illuminate once the vehicle is first started, from a cold startup.  As the temperature warms up, the lights slowly go out, indicating that it is safe to increase engine RPMs to that level.

For those of us that do not have these temperature warning lights, we rely on merely water temperature, or at the most, an aftermarket oil temperature gauge.  Even with the oil temperature gauge, when is it OK to put the hammer down?

In a study of the E39 M5, the first LED segment that turns off is at 100°F.  The lights continue to disappear until 140°F, when the last LED segment remains illuminated permanently.  For those running aftermarket oil temperature gauges, it is customary to see M50/S50/S52 derived motors reach temperatures of 180°F and higher, once the vehicle is warmed up and pushed.

Increase the longevity of your motor by allow it to warm up properly!