Rim upgrade?

Just bought a 2002 3.2 TL Type S and I love it. I'm looking for advice on wheels. If I upgrade the rims to 18"s (or larger), will it upset the way the engine, speedometer, suspension, etc. function? It currently has stock 17"s on it. Thanks for the help!

18s or 19s won't do too much to upset the speedo. Theres a website that calculates how off the speedo will be, but I can't remember which one. It might be www.tirerack.com but I'm not sure. Do a google search or a search in here, it'll show up. When I upgraded from 15s to 18s on my accord, it said my speedometer would read 60mph when I'm actually going 62.5 mph or something. Nothing too major. A tire shop can correct it for you if you want.

Other than that, the ride will be a little harsher compared to stock due to thinner sidewalls. Gas mileage will drop. Cornering will get better though. CL-Ss are the beautiful cars, especially with a nice set of feet on em. If I could afford one, I'd have one:sunglasse

here's a link that will calculate it tire calculator (http://www.miata.net/garage/tirecalc.html)

here's a link that will calculate it tire calculator (http://www.miata.net/garage/tirecalc.html)


Great, thanks for your wisdom. I'll check that link out. Any idea how drastically gas mileage will be affected?

very welcome. its what we're here for.
When I put my rims on, there was a noticeable drop in gas mileage since I upgraded three whole inches plus the rims I got are pretty heavy.

I think I used to get about 325 miles on a full tank, now I get around 275. Thats about a 15% drop if I estimated right. My rims weigh about 28lbs each if I remember correctly. The weight is more important than the size as far as mileage is concerned. Check this link (http://www.wheelweights.net/) for aftermarket rim weights.

I'm not sure exactly how accurate his table is, but its good at least for ballpark figures. Different sites will give different weights though.