I have a 92 hatch with a b18c, and I have 15 inch si rims. My friends told me the speedometer is probably off because the tires are bigger than the stock 13inch steelies, how would I fix the speedometer so it reads the correct speed ?

 

there are two ways to fix your speedo to match your mods. One, you take it to a speedometer shop, and they recalibrate it. Two, you do what cheap bastards like me do, and figure out the percentage of difference between speedo speed and actual speed, and just do some quick math to find out how fast you're really going when the speedo says 65.