I believe theaters use peanut oil. I asked the kid behind the counter and that is what he said. I declare it fact after this exhaustive research. OK, what oil to use in a SOHC ? I like the oil that is on sale, or free. How do you get free oil? When I buy a project it always comes with a crankcase full of free oil. I have done this with outboard motors, cars, trucks, and the occasional weed whacker, although the weed whacker oil has to be "reclaimed" by letting the gasoline evaporate. (petrol for you wankers) I do know one thing, if you put 2 stroke oil into the crankcase of a 4 stroke lawn mower you will get to see the piston through a hole in the crankcase in a few minutes running time. I hope this settles the oil controversy.......... Happy New Year.