I've put about 225 miles on mine since I put it on. I haven't noticed that it is changing. Feels the same now as when I put it on. Which is still a very good thing. I have noticed a "slight" increase in fuel economy. The gauge isn't dropping as fast as it did. I can usually plan on getting right at 50 miles per 1/6 of the tank by looking at the guage. Right now I have 197 miles on this tank of gas and it's still closer to 1/2 full than 2/3 empty. Usually at when the gauge is at this point I've only got about 160-170 miles on the tank. I'm guessing this it doion about 1-1.5 MPG better. Not bad considering I've been stomping on it more than usual.