Are dashcam speeds accurate?

How accurate are the speeds displayed on a dash cam with GPS?

You might wonder how accurate the GPS tracking feature on your dash camera is compared to the cars speedo. Is the watermarked speed indicator really what it says it is?

Car Speedo VS GPS Speed

For the most part, both can be accurate and both can have their issues

You cars speedo is measured by a physical source on your car, usually the rotation of your tires or the drive shaft, while a GPS dash cam uses external satellites to measure how much your car has moved.

Typically your cars speedo will be more accurate at slower speeds and the GPS dash cam reading will be just as accurate or sometimes more accurate at higher speeds. If there are any difference between the two, it is usually only 1 or 2 miles per hour.

Car Mods May Affect Cars Speedo Accuracy

Some things that might alter the accuracy of your cars built-in speedometer could be changing the size or tread of your tires or having low tire pressure. If you got larger rims for your car, this would also increase your tire size and change the speedometer reading slightly. The smaller the tire, the faster it will show your car going on your cars speedo, and a large tire would slow your MPH reading down.

Because GPS does not rely on the size of your tire to get a mile per hour reading, it can often be more accurate than your speedo if certain features on your car or truck are no longer stock from the factory, which designed the speedometer to work together with the various components.

Loss of GPS Signal

You do, however, need to take into consideration the ability to get a GPS signal and how that will completely take away your ability to get a MPH reading if you are solely going off the dash cam or GPS device for your speed. Driving through tunnels, extreme mountainous terrain or driving through a parking garage might cause you to lose your GPS connection.

Importance of having GPS in your dash cam

Even if you don’t want to use the dash cams GPS function to display your speed, it is still a valuable feature to have. After a major incident or accident, having the GPS coordinates, along with the time and date can greatly help and expedite an insurance claim.