- Dec 4, 2003
- 45
- 0
- 0
I am now on my second Speedcal. I had a Mustang specialty shop install this one, and it is still screwed up. The settings are correct for my gears. I have the stock tires and stock TR3650 trans. The speedo jumps all over the place. Mileage is either more or less. Went 10 miles, and it showed 7. On 10 mile return trip it showed 16 miles. Dallas Mustang just says keep sending them back til I get one that works....this sounds stupid. If they can't figure out their own product....how many did you guys use before you got a "good one?"