I want to swap out my cluster w/o tach to one with a tach. Which ones will fit the SPI? I have an 01'.
You’re right. Tire size does cause a difference. Although, when I first got my focus, the speedometer was off by 2mph and it still had the stock 14" steel rims on it. So when I thought I was going 55mph I was actually going 53. Then when I put my 16" rim on it got worse. I think it’s off by like 4mph now.It's probably due to your tire size compared to OEM.