My unofficial test of the Power X Wing I installed on my ultra classic. I put a total of 1625 miles on after installing riding a both highway and city with the following results. 1. No change in MPG 2. No change in drivability or throttle response with my EFI system 3. No change in power or torque that I could detect 4. Noticeable change in my bank account I will not disput the Power X Wing web site results, my test was not done with a dyno and I'm just a backyard mach. I can say the drop in my bank account is 100% verifiable. I have removed the Power X Wing placed it with the other useless harley stuff I have.