do i need to have the speedo......
do i need to have the speedo...... reprogrammed if i go from 3.23 to 3.42? My rear is howling and im changing everything.(ring/pinion and bearings) I want to keep my 3.23, but i got a good deal on some new motive 3.42 gears.
Yes any increase or decrease in rear end gear and you will need to recalibrate your speedo. But just so you know 3.42s from 3.23s will only change by 4 mph at 2k rpms in 4th gear...assuming your and A4. It wont be much of an increase but you would be recording more mileage than your actually putting on.
so your telling me that if my car is reading 10 mph OVER the speed limit ( speedo says 55, im really doing 45 per roadside radar gun) The odometer is putting more miles on the car than it is really putting on?
Yup so basically if you drove an hour at say 55...but your really doing 45 then you will record an extra 10 miles on the odometer. The speedo is controlled by the computer so if it is getting a reading from your VSS(Vehicle Speed Sensor) that the axles are spinning at a certain speed the computer will translate that according to the rear axle ratio and factory tire size/diameter.
