1999-10 Mustang Ford Racing Speed-Dial Speedometer Adjuster
Used to correct speedometer because of tire size or gear ratio changes Easy 4 wire installation No reprogramming of PCM necessary Fits 1994-2004 Mustang with manual and automatic transmission Fits 2005-2010 Mustang with automatic transmission. Will correct speedometer to equivalent of 10% gear ratio change higher or lower Fits 2005-2010 Mustang with manual transmission. Will correct speedometer. No limit on magnitude of gear ratio change for manual transmission vehicles
The Speed-Dial scales a frequency based vehicle speed signal up/down to maintain accurate vehicle speed indication to the instrument cluster and PCM.
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.