Not that it matters, but where are you getting 16.09? I always thought it was close to the same as gasoline, and my quick google search shows 14.5:1.There are different perspectives of lean. True meaning of a lean burn is based on your afr on what side of stochio metric it is on. But u can run leaner on either side. Less fuel. Stochio perfect mix is 16.09-1 afr. If we want to get all technical and what not james