DYNO 102 - I think we are all past 101!
WHP
1. Used commonly by americans because their many of their dyno's do not measure anything else. (worked there for 2yrs)
2. Valid for comparisons on the same car, same day, same dyno.
Transmission loss - more accurately Rolling loss
1. Not so much the frictional losses in the gearbox/diff BUT the double convex deformation of the tyres on the relatively small radius rollers.
2. "Rolling losses" are affected by tyre pressure and manufacturer but ultimately speed, the loss at 100MPH will be over double of those at 50MPH.
If we want to see high WHP we would pump up the tyres nice and hard and run in as low a gear as possible.
Therefore comparisons between two cars' WHP are simply not possible because of the above.
Jamie