The speedo in my wife's car runs slow, when you're doing 70 the speedo reads 58. When I bought the car it had 235/55-16's on it. I figured maybe it was supposed to have 245/50-16's. So we put new tires on it this weekend and the speedo is still wrong. I checked the gear ratio physically by turning the driveshaft and tires and counting turns; comes up 2.7. This puts it at 2.73 of course. Do you think somebody switched it to this? I know these gears are standard on an A4 car. What gives??

 

What "GU" RPO is on the code sticker?
GU2 : AXLE REAR, 2.73 RATIO

GU5 : AXLE REAR, 3.23 RATIO

 

Thanks shoebox---- Where do I find the code sticker? I'm thinking that a Hypertech or Superchips would fix the problem

 

It does say GU2 on the inside of the driver door. 2.73's. Maybe I need a new speedo cable? This has to have happened too someone else also...............

 

ttt