I am with Paddy as well. I don't have 25 years in the industry, just a four month senior level college course, Internal Combustion Engines. It was taught by a guy who was trying to get out of the engine industry and into teaching. He had over 20+ years of engine research at Southwest Research Institute. Basically, engine designers are trying everything they can think of to optimize the fuel/air ratio.

As an alternative, you could always ask the mythbusters. <img src="/forums/images/graemlins/grin.gif" alt="" /> <img src="/forums/images/graemlins/grin.gif" alt="" /> Sometimes their test method is a little shaky, but most of the time they do a good job. <img src="/forums/images/graemlins/wink.gif" alt="" />