Jason Cammisa of Automobile Magazine decides to verify BMW’s 302 horsepower and 400Nm of torque claims on the BMW 335i specification sheets. The results did not disappoint, instead strangely the BMW 335i that Cammisa put on the dyno made alot more power than what’s on paper!
Typically, a dyno of power at the wheels would show about 20 to 25 percent drivetrain losses compared to the figures the manufacturer provided which is at the crankshaft. BMW’s 330i sedan which is rated at 255hp and 300Nm of torque at the crankshaft by BMW resulted in about 200hp and 245Nm of torque when dynotested at the wheels. The dyno machine used is a DynoJet dynamometer. That’s about a twenty percent loss, in line with our rough 20-25 percent drivetrain loss estimation.
However, the BMW 335i made 275hp and 406Nm torque when dynoed at the wheels! Even more torque at the wheels than BMW quoted at the crank? This would mean the BMW 335i in question is actually making close to 350hp and 480Nm of torque at the crankshaft, alot higher than BMW’s rated 302hp and 400Nm! Dyno chart can be viewable if you click the image on the left. Torque is rated in lb-ft on the dyno chart, but I’ve done the appropriate conversions to Nm for this post.
Is this by freak chance or is BMW underquoting the BMW 335i’s performance on purpose? If it is underquoted, why? Anyone with a BMW 335i Coupe who wants to re-do the dyno test?
BMW 335i Driving Experience