ELECTIVE POSTING OF DYNO RESULTS:
Posted upon consent of member; please check back for updates.
HP ratings will be lower than numbers posted by BMW
- HP here is measured at the rear wheels (power to the ground)
- HP numbers from the factory are measured at the flywheel
- power loss is transmitted through the drivetrain from engine to the rear wheel (transmission, drive shaft, axle, etc.)
- bear in mind performance numbers are affected by ambient weather conditions as recorded toward the bottom of each dyno graph.
Flywheel Horsepower vs Rear-Wheel Horsepower:
"The difference between flywheel horsepower and rear-wheel horsepower will vary from vehicle to vehicle, depending on many factors," adds Gale Banks Engineering, "but we find that rear-wheel horsepower is usually between 18 percent and 25 percent less than flywheel horsepower."