Skip the auto shop - Our mechanics make house calls

Q: Speedometer 5 MPH too slow

asked by on

The van is going five miles under the speed it is showing on the speedometer.

A: Speedometer issues are not very common and ...

Speedometer issues are not very common and sometimes can be caused by things we do. For example replacing the tires. Tires need to be replaced with tires of the exact same size because that is the size that is programmed into the vehicles computer. So the speedometer calculation is done based on that. If you have replaced your tires with a different size, the vehicle can be reprogrammed to the new tire size so that it all works correctly. This is something that the dealership will need to do for you as it is a factory setting. If you have not replaced your tires, but are still having issues, it might be caused by the speed sensor in the transmission. Some vehicles have two speed sensors. A qualified mechanic can determine the speedometer issue and replace the necessary parts to get it functioning properly again.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: When starting noise from engine

The rattle is coming from the camshaft sprocket on one or both cams. To get rid of the noise the cam sprocket would need to be replaced. These are part of the variable valve timing system and this is only...

Q: Rear sensor replacement did not fix speedometer needle

Hello. If the sensor is fine then the instrument panel is the problem. It is common for the motor that runs the speedometer needle to fail and cause this. It would require that the instrument panel be replaced. If you...

Q: Cyclic noise when it runs

Cycling noises are common in cars with low refrigerant levels. When the refrigerant is low, the A/C system has a pressure sensor that turns the compressor off to avoid damaging it. Once the pressure gets to a good point again,...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.