Re: Oil Change
Along Dave's lines we used to run engines on propane. Absolutely -0-, nada, contaminates of any kind. You can almost never change the oil. Whatever you add keeps it semi fresh. Change the filter occasionally. You can take a propane engine apart with 100,000 miles on it an will look like it went together yesterday. The downside is it's really hard on exhaust valves but especially seats. With hard seats, which virtually every engine has these days, a propane engine will run for a very long time.