Fuel Saving Tips

GPS vs Speedo

Contrary to what has been said here before, differences between GPS and Speedo/Odometer are NOT because of any laws. Since elevation estimates from the GPS are generally 3 times more prone to errors, this also means that GPS speed calculations are affected. You GPS unit has logic that takes its data and "plots" you effectively onto the closest road The bottom line is that GPS indicated speed will always be variable, and subject to small amounts of variable error. Your speedo, OTOH, may be slightly off- however it will be off by a constant ratio. Trust the speedo - NOT the GPS.