-Used to correct speedometer because of tire size or gear ratio changes
-Fits 1994-2004 Mustang manual and automatic transmission
-Fits 2005-2010 Mustang with manual transmission. Will correct speedometer. It has no limit on magnitude of gear ratio change for manual transmission vehicles.
-Fits 2005-2010 Mustang automatic transmission. Will correct speedometer to equivalent of 10% gear ratio change, higher or lower.
***NOTE: To maintain cruise control function on 2005-2010 Mustang automatic and manual transmissions, gear change is limited to equivalent of 5% higher or lower ratio (<+/-5% change). For example, a gear change from 3.55 to 3.73 results in a gear ratio reduction of 4.8% so cruise control will continue to operate normally. A gear ratio change from 3.55 to 4.11 results in a gear ratio reduction of 13.6% so cruise control operation is lost.
-The Speed-Dial scales a frequency based vehicle speed signal up/down to maintain accurate vehicle speed indication to the instrument cluster and PCM.
-Easy 4 wire installation
-No reprogramming of PCM necessary