1- Is it ok to run a synthetic oil for a period of time and then switch back to regular oil. ( Lazer HP/23HP kawi)? 2- Is it ok to run a multi-viscosity synthetic (Mobil one) in a commercial mower? I've heard that there is a consumption here is hat true? If so, how much would you expect to consume in 40 hours (Myoil change rate) I like the idea of getting Mobil One (5 quart jug!) at Walmart! 3- I am currently running Amalie(sp?) High performance 30W. O don't think I've ever seen an oil pour so clear. Anybody use it on their mowers?