I bought a brand new car Toyota Matrix XRS, it comes with 18 inch low profile tires. I have external GPS and Anti COP Radar both of is showing lets say 35mph and car is showing 39mph. I tested it with my other car and if radar, and gps how 35 car is showing 35. Those RIMS came stock on that model car, do you think it has something to do with that. Also is it just speed that is incorrect or could it change the actual millage of the car? Should i take it to the dealer to calibrate speedometer?Can Bigger Rims Change Speedometer and Odometer?yesCan Bigger Rims Change Speedometer and Odometer?first, definitely get the speedo recalibrated if the speed is inaccurate. if those 18's are stock, then the speedo is definitely innacurate. milage can also be affected by the speedoCan Bigger Rims Change Speedometer and Odometer?Larger rims create a larger circumference for the tire so when the speedometer is reading 35 you are actually traveling a further distance at a greater rate of speedCan Bigger Rims Change Speedometer and Odometer?This should have been programed into your vehicles computer at the factory during production. It could have been over looked. This should not cost you anything at the dealership to have it checked since the vehicle is new.Can Bigger Rims Change Speedometer and Odometer?yes you will have to take it to a dealer to get it recalibrated because i kinda doubt you have the computer tool dealCan Bigger Rims Change Speedometer and Odometer?Every timeCan Bigger Rims Change Speedometer and Odometer?I remember sometime back a ruckus about Japanese makes having speedometers that were too fast from the factory. Warranties ran out quicker.
Seems like another case of that.
