I have a 92 civic hb with a b16a3 motor the car right now has 16" on 195/60's. My spedometor is dead on. The del sol this motor came out of had 14's stock. I want to go 15" but I don't wanna my spedo to be off. How couldve the previous owner had adjusted the spedo, also it's a y21 tranny if that matters. I was hoping to go 15" with 50 series side wall. Apparently that ain't going to work with keeping the spedo accurate. Any ideas?

 

brain fart hmmm

 

Is the speedometer adjusted to the 195/60/16's? Because those tires are seriously oversized for the chassis. They're over 10% oversized, which is a rather unsafe amount. Safe amounts are less than 3%. Furthermore, if the speedometer is calculated for the 195/60/16's, you're going to have a very difficult time finding tires in a size that will keep your speedometer accurate. Even 195/70/15's are undersized, by comparison. So your hopes of a 50-series sidewall aren't feasible.

 

195/45R16 (recommended) is at 22.9" in diameter, and stock was 22.7". The 195/60R16 is 25.3" so maybe you read the tire size wrong.....