It's more like 3.5 hp. when you take into account the terminal velocity of air on a average summer day at 70 degrees and 82% humidity the air molecules when rushing pass stock fenders which are made out of high density polypropylene Reduces air flow by 32.33% now that is just driving at an average 47.8 mph. when you take into account the shocks ability to flexoer your frame where by being mounted just under your fenders it reduces air flow by another 12.35 % when jumping through air where by giving you a 44.68% reduction in air flow velocity versus shaving your fenders. moral of the story....haha just pulling your chain. I don't know really what shaving fenders will actually do for you just riding around. I can see maybe flat track racing would have some drag effects but i don't think it would be a whole lot unless you start getting over a 100mph. plus i think shaving looks better.