Mustang Dynos, I find, always dyno about 10-20 HP lower than they should. I got my car dynoed on a Mustang, and I was happy I hit 109HP. Now if I were on a Dynojet, I'd be at like 119 or 125 ish. I've heard that the Mustang Dyno was more accurate, but the only people that ever say that are the salesmen or the people that have them in their shop. But I must admit that most of my runs were very consistent. Made maximum torque from about 4000 rpm to almost 5300 rpm on almost every one, and once I started losing torque, my horsepower took over at 5300 rpm and leveled out and held to redline, again on almost every run.