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: Was they right

Your car has two coolers, one in the radiator, and one in front of the radiator. The one out front is the one that is more likely to leak. There are three options to repair the leak. First, you...

Q: Broken speedometer

Hi. The most common problem is the instrument cluster followed by the vehicle speed sensor on the transmission/transfer case(2wd/4wd). You will have to use a scan tool to determine if the VSS signal is reaching the instrument cluster. If you...

Q: Poor fuel mileage

Hi There, There are a number of things that can cause poor fuel mileage. A faulty camshaft position sensor is one of them. The camshaft position sensor is a magnetic sensor that monitors camshaft speed to regulate ignition timing and...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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...