Ever since i bought my car two years ago it seems like the spedometer reads faster than what the car is really going. Ive riding side by side on the highway with a friend and his car is pratically brand new and his speedometer would say like we were going 10 Mph less than what mine would say. I replaced the VSS less than a year ago any ideas?

 

Do your current tire diameters match the stock tire diameters. If your current tires are smaller in diameter then it would make your speedo think you were going faster than you really are.

This probably isn't the cause of your problems though because you would probably need to be like 2" off or something like that to make your speedo read that far off. But it's something to double check.

 

No i have the stock wheels and the tires match specs for that year it seemed the same when i had my 17s on there too but those havent been on it almost a year

 

Have you ever had the speedo inspected to make it isn't broken itself? Maybe try removing it and having a shop that does that kind of work look at it or try replacing it with a known good unit.

 

u can do a dyno run and see if ur speedo matches the dyno's speed, also if u have AAA they do free speedo testing every month at diff locations, goto the AAA website and look at the services if u have it

 

Or you can go to a track and see your capture speeds at 60ft 1/8 and 1/4mile. And compare it with most others running the same times as you. If its of by 10 you'll know

 

Borrow a GPS receiver (or buy&return)... that will tell you the speed. BestBuy has them, Walmart has them...

 

thats cool i didnt know that AAA does speedo testing ive never heard of any shops doing that kind of work. another thing it seems that the tachometer corresponds with the speedometer according to the owners manual maximum shift speeds

 

I cant find on the AAA website about the speedometer testing