Why are we talking about horsepower anyway? The post is about fuel economy as for that I have an '01 G.P. SE and get between 21-28 all around driving. Also have a 1986 Monte SS with a twin turbocharged ls1 out of 98 camaro and whe I kepp my foot out of it without the tubos spooled up I get about 19 mpg rarely! but that is also VP purple race fuel. 7 bucks a gallon! LOL