Originally Posted by T Bone
Can't say what compromises the factory made. I am unsure if the S65 V8 has an electric water pump but the S85 V10 is belt driven. The car does dyno better (+28 RWHP) at the expense of a slight temp increase.
in the M5 / M6's the slight increase in temp doesn't seem to affect anything and universally people think the engine revs quicker.
The water pump in the S65 is belt-driven; transmission cooler pump is electric. I guess I'm past the point of pushing things that far for a non-racing car. Ask me in a couple years, though!