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 ...

Q: I have a 1995 automatic Honda Accord LX and the speedometer and odometer work intermittently. I noticed that both work (but not always) on warm/hot days and do not work at all on cold days. The car ...

Remember calculating which speedo drive gear would make your speedometer and odometer read accurately after a gear and tire size change? if you own a new JK wrangler, those days are gone. Now the ...