well, I know, BUT, I went backwards on the pulley size, so I know that didn't help. I think the only other thing that could have helped is the factory fan over the flex fan possibly? Its just crazy because before it would just climb and climb until I finally had to park it, and now, even with a 180 thermostat, it wants to run at 170 when moving! you can tell when the thermostat closes because it will go to 180 and then drop right back down when it opens again. I love it!