While I don't have my Challenger "YET". In my 2000 Dakota 4x4 with the 4.7 magnum I have averaged 14.3 mpg since I bought it 8 years ago, so I cant wait to get my R/T and see how much MORE mpg I get with it. Over all though I am a pretty conservative driver but I do step on it at freeway onramps just to get up to merging speed.