If you've ever modified a car with smaller or larger tires or, perhaps, a different final-drive gear, you've immediately screwed up your speedometer. This is, of course, annoying, but for modern cars ...

Question: Three months ago, I purchased a 2010 Jeep Wrangler Sport. It came with P255/75R17 tires that are larger than the original tires, which were P225/75R16. Is there an easy and inexpensive fix ...

Yes, but just a bit. A car measures the rotations of the axle and wheel. The speed is the distance traveled per hour (speedometer reading). The distance traveled (odometer reading) is rotations ...

Question:I have a 2004 Ford F-150 and the speedometer quit working, but the odometer still works. I heard that disconnecting the battery would fix it. It did, but only for a couple of days. Does that ...