After purchasing and (properly) installing the e-RAM on your engine, you do not feel that the performance increase is what we have claimed (4%-6% HP increase), you just need to do the following within 30 days of receiving your e-RAM to get a full refund*.. Take your car to a dyno test in your area. Make dyno runs with and without the e-RAM activated, and take a picture of how it was installed. Mail the e-RAM back to us with the picture, a copy of your receipt, and a clear copy of your dyno comparison results (signed as witnessed by the technician running the dyno). If the dyno shows the e-RAM does not increase horsepower in your engine by an average of at least 4% of its previous horsepower throughout the 3000 to 6000 rpm range, and we conclude from the picture that you have installed the unit correctly, we will give you a full refund* and even pay for 1/2 your dyno fee! (up to a maximum of $50 reimbursement) *Full refund does not include shipping charges *Please see "compatibility information" section below We challenge any other manufacturer of aftermarket bolt-on horsepower devices to make the same commitment! We know it works!