Speedometer reads about 1 mph over actual speed, when compared to GPS, radar advisory stations, and using a stopwatch along a "speedometer calibration corridor" on US-31 just south of Indianapolis.
When traveling at 69 mph, the car reads 70. When traveling at 54 mph, the car reads 55. When traveling at 24 mph, the car reads 25.
We first noticed this when traveling in 70 mph traffic, and everyone was going just slightly faster than us. When we increased our speed to what the car said was 71 mph, we were going the same speed as traffic, and not creating a nuisance to other drivers.
Speedometer reads about 1 mph over actual speed, when compared to GPS, radar advisory stations, and using a stopwatch along a "speedometer calibration corridor" on US-31 just south of Indianapolis.
When traveling at 69 mph, the car reads 70. When traveling at 54 mph, the car reads 55. When traveling at 24 mph, the car reads 25.
We first noticed this when traveling in 70 mph traffic, and everyone was going just slightly faster than us. When we increased our speed to what the car said was 71 mph, we were going the same speed as traffic, and not creating a nuisance to other drivers.
- Allen M., Versailles, US