It is commonly said that engines running propane, vs gasoline, last longer.
Taking out the factors such as application, I am inclined to think this is because upon cold start, the propane engine does not require a rich fuel mixture. The rich mixture might result in condensation on cylinder walls in a gasoline engine. And in a diesel engine, fuel may be sprayed and may collect on the cylinder wall prior to engine start. But in a propane engine, the vapors, at least in temperatures above arctic temperatures, are unlikely to condense on the cylinder walls. Without the washing of the cylinder walls, there is less start-up wear.
My assumption is that this is the primary reason for longer life with propane as the primary fuel.
My question is: Is there research to back this up (or refute it)? Of course, some cites would increase credibility of any answer.
