Curious about HP loss through the drivetrain.

[KRAM36]

Got this info from a Pelican article.

Porsche Boxster Dyno Testing - 986 / 987 (1997-08) - Pelican Parts Technical Article

Driveline Losses: Since the dyno testing is performed using rollers on your car, there are going to be forces that are going to slow down and reduce the power in-between the flywheel and the rear wheels. These driveline losses include friction from the transmission, losses from brake discs dragging slightly, and friction in the wheel bearings. On the Boxster, typical driveline losses are often estimated at about 15%, although modifications to the chassis can raise or lower that value. Through a complicated process of calculations that are computed by the dynamometer, you can calculate your driveline losses by counting the time it takes the dyno rollers to stop when you let out the clutch. Using these calculations, you can then estimate what your horsepower output is at the flywheel.

So you can calculate the drivetrain loss. I don't know how you could do that with a Tiptronic though. Moving the shifter to neutral wouldn't be the same as letting out the clutch, would it?