This is the dyno chart from my 1993 Nissan 300ZX Twin Turbo as purchased (I call it "version 1.1" because it was slightly modified at the time.) The output at the wheels was 267 ft-lbs of torque and 249 horsepower. That was a couple years ago.
Remember, HP measured at the wheels includes inefficiency of the driveline from the flywheel on back. The usual rule-of-thumb is that a front-wheel-drive car looses 15-16% in the driveline, a rear-wheel-drive car looses 17-18%, and an all-wheel-drive car looses 19-20%. All that assumes the motor is in the front of the car.
Engine HP: 300 (factory claim)
As-measured HP: 248.7
(...so if you divide measured HP by 0.82 or 0.83 you get about 300, confirming the rule-of-thumb if you assume my 8 year old car performed as the factory intended.)
