ACECARDigital GPS Speedometer, Car Universal HUD Head Up Display with Speed MPH, Compass Driving Direction, Fatigue Driving Reminder, Overspeed Alarm Trip Meter, for All Vehicle (G4S-green)

This thing is pretty cool. I'm using it in my 54 Nash. The original speedo is very inaccurate. It's easy to calibrate. I calibrated in a new car and set the cruise control on 40mph. It read 3mph fast. I changed the calibration setting from default (107) to 104. That part is weird and I don't understand that kind of interface. But it was easy. Just weird.It dims down comfortably for night driving.Moving the thumb wheel to the left turns the speed alarm on or off. Just don't move the wheel to the right. It sets everything back to default, for some strange reason.

The cord stays in the way the speed is not quite accurate it’s always off by 10 to 20 mph the directions come written very small and are not clear on how to set it

I bought this digital speedometer and GPS compass mainly for the compass function. I already have an accurate digital speedometer in the car. But the compass reading is very small and if your eyesight is 20/20 you can read it with no trouble. The speedometer is factory set to read about 3 mph faster than your actual speed. I don’t know why. There is a calibration you can do to adjust that. I haven’t tried it because it requires that you be going 60 kmh (about 36 miles an hour) and then doing a trial and error adjustment — or so the non-english speaker prepared instructions say. ( I may attempt to simply adjust it against the built-in speedometer.) So it’s really a redundant speedometer with a barely readable compass that does seem to be accurate and unaffected by the metal of the car.

The display is easy to see during that day time and at night. The only thing they need to improve on is labeling the menues. If you lose the instructions, Goodluck on ever making any adjustments.The over speed setting is nice to have especially for new drivers who are good at maintaining a constant speed yet.

Works great. Use the instructions to set up otherwise you’ll be lost. Had a test video and pictures but for some reason Amazon wouldn’t let me post the media. Good bang for your buck speedometer. I’d buy again.

Everything on the product worked as described. Because I put oversized tires on my vehicle this speedometer was not quite accurate anymore. I was able to finally tune this product to display an accurate speed.

No matter where I’m at or where I go. How many times I reset it. It just doesn’t get GPS signal and doesn’t work at all.

My Motorcycle display is in Km and I needed mph. There is no setting to change this. Bought this and added a on off micro usb charger and it works perfect. Drove by one of those radar signs on the road and it matched the speed perfect. Thanks.