My neighbor has a propane fueled 30 KW Kohler with less than 400 running hours. We just had a 6 day power shutdown, and the generator was working fine until it shut down due to loss of oil pressure. It was down over 2 quarts on a 4-5 quart crankcase. The spec. says 5W-30 synthetic oil. The dealer said it needs to be checked every 24 hours, which, of course, requires a shutdown each time. After filling, it ran fine, and after another 36 hours, the oil was down over 1 quart, and the dealer says this is normal. I find that hard to believe. I have a 12 KW Kohler, and the oil level is down maybe a pint, and that is after about 250 hours since the last oil change. My spec. says 10W-30 synthetic. I'd be interested to know of others' experience on this subject.