Alright when I got my pcm programmed I swore I told them I had 3.73 gears so they know to change it to 3.73 gears. I also told them I had 275/40/17 tires. But when I get to 2000rpm in 6th gear I am only doing 74 or 75mph. When I get to somewheres between 2200 and 2300rpms I am now doing the 82mph that I am suppose to be doing at 2000rpms with the 3.73. Do you think my tach is off by that much on my car? Or did they program my computer wrong? Thanks for any help.

 

same thing happened to me. tach is probly off.