Re: Tire size /odometer error
If, however, the previous owner (assuming it was bought used)had it recalibrated for a certain tire size, then the circumference equation would possibly be inaccurate. I had mine recalibrated by Ford and was told they could only do it 6 times and even then could only calibrate it to the largest tire Ford put on the Bronco for that year. In my case it would have been 31-10.50s. Since I was running 33s at the time it didn't help much and I was still 10% off. So, when I went to 35s, I used the mileage check points on the freeway. Did it with a set of 35" BFGs and 35" Les Schwab tires. Both showed me to be off around 14%. So Broncobilly, when I am cruising at 65 on the freeway per my speedometer, I am actually going 74 and for every 100 miles on the odometer, it is actually 114 miles. I did just the reverse on my daughter's Honda. Put smaller diameter tires on it and she thinks she is going faster than she actually is (lead footed girl).