Originally Posted By: SpitfireS
Originally Posted By: d00df00d
The high oil consumption in M engines comes largely from "loose" piston rings, which have to be used to minimize friction.
Honda engines are small displacement 4-cylinder engines, and they tend to use internal dimensions that are a little more sane. They can make similar specific outputs, but they just don't have as much going on inside them as BMW engines do. That's why they can get away with using more down-to-earth oils.
Honda uses the FRM cylinder walls to reduce friction.
FRM = Fibre Reinforced Metal.
@ 9000 rpm there is a lot going on in my F20C2, 2.0l four cylinder S2000 engine.
Still, Honda recommends a 10W-30 (dino) oil.
Specific output for the F20C2 = 120hp/liter.
Designed in 1998/1999.
I think wear/load should be meansured by torque per liter, because "HP per L" is only a multiplication of said torque. If the torque levels are low, ie 156ft/lbs, then suddenly 245hp acheived by multiplying 150ft/lbs over 3 times the power strokes as a production car engine, isnt very impressive at all. In fact each power stroke delivers a fraction of the torque per power stroke as the regular passenger car engine pushing 150 ft/lbs through ONE power stroke at 300rpm, undoubtedly seeing high compenent loads. High revving Hondas are very low loaded engines, because they produce very little torque per power stroke. The BMW, while making a similar powerband, has no excuse however, for bearing failures.