Going 70mph, both of my gps records me going about 65-66 and when i pass through places that show my speed, it usually reads 3-5mph slower than what im going. My cluster has never been tampered with, also im rolling on stock 195/55/15 tire size.

anyone else experience this?

 

it's pretty standard. Going with a larger tire would help with the speed discrepancy.

 

Hi there! This post is a little old, but I believe I'm having the same problem with my integra. I'm travelling at 80mph on my speedo, but I've verified through the GPS and pacing other cars that I can see their speedo that I'm really traveling around 74-75 mph. So its quite a difference. I've been trying to find an answer but not sure what the problem is. As far as I know the VSS and cluster has not been tampered with. Wheels are stock size, 195/55R15. I've read everywhere else on Google that the wheel does change it somehow, but it shouldn't by that much. Anybody have similiar problems? Any solutions? Thanks in advance!

 

Typically on any GPS navigator, your cluster speed and the speed recorded on your GPS will almost never be exactly the same. If you're anywhere from 1-3mph off on your GPS then most likely your speed is correct that is if you're running the correct tire sizes and rims. A difference of 5mph or greater is quite a difference so there might actually be a problem here. For example, my brother swap his 96-00 civic Ex cluster for a 99-00 civic Si cluster. After the swap, the difference was about 5mph according to the GPS. So we swap the stock cluster back, and we we're only off about 2-3mph. We did the same for my cousin's Ek hatch. We swap his cluster for the Si cluster he bought and the results were exactly the same. I also tested it with my stock 97 Gs Integra (with proper tires and rims) and the results were identical. I couldn't confirm for sure so I decided to test it on my dad's 2001 Tacoma which had only 50k on it. The results were similar. It was only off no more than 1-3mph. Plus you have to consider the year, type, and model of your GPS. Newer models tend to be more accurate. You also have to consider that there are defects in measuring your car's speed since, in this case, it is done with the use of satellites. Last but not least, on average most cluster are off by a few to a couple hundreds of rpm. Same applies for the mph.