SinoTrackGPS Speedometer for Car Universal MPH Speedometer USB Connect Large Digital Speed Display Heads up Display Plug and Play Compatiable with All Cars Vehicle Truck

I love this easily add on way to see my speed as I drive. I tend to not look down at it as much as I really like to just keep my eyes looking forward and checking mirrors. I have not been great in doing the speed limits on have been pulled over of going a bit to fast and this is nice way to keep that number really at level if you car does not a larger display you can be going with traffic or when no traffic get a heavy foot. This keeps you to keep you speed in check and adds a nice layer of safety when many are not focusing on driving and driving way to fast

I really hoped this would solve a problem that I have with some of my vehicles. I’ve got several muscle cars & an old 4x4 truck that all have speedometer errors due to tire size and axle ratio changes. When I switch from the Nova to the Camaro to the truck, I usually use an app on my phone to refresh myself as to how much each one is off. I thought this GPS speedometer would be easy to swap from one vehicle to the next to make sure I know how fast I’m going on the highway and in town. Unfortunately, after testing this in two unmodified late model vehicles, comparing it to an app on my phone (also GPS based), and even using a stopwatch and mile markers on the highway, I’ve concluded that it reads about 9% higher than the actual speed. None of my vehicles are off more than 10-15%, so this amount of error doesn’t help me at all. On the plus side, the display is easy to read, it’s super easy to install, and I like the suction cup mounting bracket. I’m sure for some applications (maybe a UTV or something) this would be accurate enough, but it doesn’t do what I was expecting.

I got this device thinking it would be a good way to check the calibration on the speedometer of a car I am putting together with a non-stock tire height, a rear axle from one car and the trans from another. I tested it using my daily driven Prius which is stock except for the model of tire used (originally came with Bridgestone Turanzas and now has Bridgestone Ecopias in the stock size). I found it read a bit faster than the stock speedo, which itself is 1-2 MPH fast. At 10 MPH it is about 1 MPH fast while above 50 MPH it is 3-4 MPH too fast. So, it would be OK to use in a vehicle with no speedometer, but useless if you need an accurate measurement. As for the unit, I like its small size and easy to read, bright LED display. However, I do not like that the Micro USB port that powers it is on the back as that limits your mounting choices. It also only has a slot on the back to hold it to a suction cup mount and has no threaded inserts to make a custom solution from. It also has no internal battery, so using it on a bicycle would be difficult without an external power bank. Even then, it would be hard to mount. This also means that a good bump will make it reset since there is no internal buffer from a battery or capacitor to see it through a momentary loss of contact. For this price though, if you can deal with the limitations, it is an OK buy.

This little thing works great and is easy to see!Normally connects within a few blocks from leaving my house and it's super easy to read!