There is variation in requried oil content among gas engines - plain bushed conrods require notably more than those with needle bearings for example. I am not 100% sure but I think we could get away with less oil if the connecting rods ran bearings versus bushings - IIRC that is one of if not the highest demand location for lubrication.

Slightly OT but a common mistake with gasoline engines is to run oil:gas at a lower ratio than the engine manufacturer recommends, usually because the oil bottle says "50:1" or something like that. The engine manufacturer knows the requirements of the engine based on metallurgy, bearings or bushings, etc. and makes a recommendation accordingly which should be followed. The ratio on the premix oil bottles refers to the minimum ratio that it can be mixed at and maintain film strength, not the ratio that it should be used at in any engine. An engine calling for 50:1 for example needs an oil rated to mix at up to or beyond that ratio. An engine needing 20:1 can run "50:1" or "100:1" rated oil but it needs to be mixed at 20:1.

MJD