Originally Posted By: dwendt44
Most OPE engines, yard tractors included, are air cooled. And air cooled engines run hotter that a water cooled auto engine does.
They are more similar to motorcycle engines, many of which spec. a 20W-40 or heavier oil. Think Harley-Davidson, Victor, BMW. etc...
Then why do many manufacturers of air cooled engines show 10W30 as one of the recommended oil viscosities?
We have had numerous discussions concerning the durability of decent quality OPE engines. Several participants have posted stories of mowers that are decades old with poorly maintained engines running on a few tablespoons of residual oil from the original fill or at the very least, well used oil many years old. Yet they continue to run and run fairly well despite the neglect. I know I've seen my share of it.
My point is that far too many owners of OPE have oil anxieties concerning brand/type and viscosity. Where, in reality, the engine doesn't care one way or the other as long as it has relatively decent oil in it's crank case. Use any reasonable quality oil of recommended viscosity and change it as per engine's manual. The engine will probably outlast the machine it's mounted on barring catastrophic failure.
When was the last time anyone here had an engine blow up because they used regular, off the shelf 10W30 in their OPE rather than something more expensive?
I've been running $1.79/liter Shell Formula 10W40 in both my riding mower engines for a couple years now. No oil consumption, no smoking, no difference in engine performance or sound. They just keep on doing what they're supposed to do. Accordingly, why the need for more expensive oil?