|
You're right,
1 PS = 75 kp·m/s = 0.73549875 kW = 0.9863201652997627 hp (SAE).
Explains why the horsepower ratings on the bmwusa.com site have always seemed a little off. Silly to be changing measurements on such a little unit. I think everyone should just use kiloWatts as is the international recommendation for automotive industries. I just wonder why the 265 DIN hp Z4 3.0si is shown as 255hp (should be 258hp SAE.), and the Z4 3.0i as 215 SAE HP (should be 227 SAE HP) on the US site. Perhaps they do round up numbers a bit, because at least the N52B30 and M54B30 engines are the same, they're shipped from Germany to the factory in Spartanburg for the Z4's and they do not put different units into different market cars, as there is no emission requirement difference on the "regular" Z4's. However, there must be an octane difference on the measured SAE hp's which BMW USA obviously measures themselves and the specs call for lower octane fuel than the DIN HP specs. I'm too tired to look it up on Google right now, so that must be it... Most available US gas is of lower octane rating anyway... (Yes, I know the difference between RON and ROZ octane ratings)..
Even the N52B30 pot gets about 10 DIN hp increase merely by using 99+ octane (RON) gasoline as compared to regular 98E unleaded. (Tested in a roto-dyno.) (And also decreases overall consumption by about 0.5 liters per 100 kilometers on extra-urban driving.)
Best regards,
Jussi
|