stevebez

See this...

http://www.rri.se/popup/performanceg...p?ChartsID=152

So they say there is a 5% drivetrain power loss and a 8% drivetrain torque loss... This efficiency of the drivetrain is unheard of ... the engine is producing more power than what the manufacturer states. Period.

By example the C55 has this chart

http://www.rri.se/popup/performanceg...p?ChartsID=607

and has 10% and 11% loss respectively - even this is quite good.

The M5 comes in as follows ....

http://www.rri.se/popup/performanceg...p?ChartsID=153

7% and 9% respectively ... so maybe even that motor is underrated...?

Any thoughts ??? - great database on this website....

EDIT : Think I misread this ... the data is the rated output adjusted for drivetrain loss ... I think....!!!?????

Ted Baldwin

............the percentage difference stated on the chart is the not drive train loss. It is the difference between manufacturer claims and that measured by the testers. The E55 did not make 446RWHP. That number is the final crank HP after measurements and calculations by the testers. It is then compared to the 469Hp that manufacturer states. I know the chart has RWP on the left column, but I think it only refers to the 333 which then converts to 446cran HP.

Ted

Fikse

by their dyno, it looks like most cars are overrated by the facotry.... even the 2006 Z06, which they say is only making 475HP..... even though Chevrolet stated the Z06 is "certified" at 505HP by the new standardized SAE testing standards that the manufacturers must comply with......

stevebez

Maybe drive train assumptions are out - the Golf GTI is the only one I have found that is very close to advertised spec....

Its good to note though that the CLS55 is one of the better results.

I like the standardised system they are trying to adopt ... makes good sense.

stevebez

According to Page 7 of Part 2 below - the reported HP is WHP unadjusted for driveline loss....

Perhaps someone can verify this ????

http://www.rototest.com/index.php?DN=32&Visitor=4

Grumpy666

The peak HP numbers for the CLS/E are at 6100 RPM, so they're probably using third gear for the measurement to avoid the speed limiter. I suspect that their inflated wheel HP & torque numbers contain a gear ratio adjustment factor.