Not sure which 2011 Dodge Ram Speedometer Calibrators are right for you? We have over 11133 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Blaine S from Virginia Beach, VA said, "Used it to calibrate my speedo after increasing tire size to 35's. Easy as following the directions . make sure you know in inches your tire size before u begin . Easy easy"