Hey, not sure if this fits here. My car had fourteens all around. I put cooper cobra radial gts on my car. P145 60R14 on front and P155 60R15 in the back, rims are sized accordingly. My speedo is no around five mph off (well, it says im going 60 when i am goin 65-friends checked me out w/ five different vehicles, all brand new) I know nothing about the gauge situation in my car... So i could use a little advice on how to remedy my problem

PS. Sorry about this post being so gramatically challenged.. Im rushing around today

 

The remedy is in the gear.There is a gear at the trans end of the speedo cable that you need to change to correct your MPH.

 

Yeah, you need to know your rear end gear ratio, and the size of your ties and you cna calculate the correct speedometer gears. Just post them here and someone will tell you what you need.