right size tires, for no speedo correction needed? Options

[eclipse_04a]

can someone make the list and then sticky it? it was kinda started in the 20" rims thread, but thats the info im looking for. and if you need speedo corrections, what are your options? the only one i know of is to get speed hut to do custom gauges for it.... i think this info should be stickied at the that top, and if it is, and i missed it, could you be kind enough to post a link? thanks.

[97GTinKC]

23.90" is factory tire height, so any tire/wheel combo within a quarter to half inch of that overall height will not noticeably affect the speedo. should be able to use 23.75"-- 24.25" and stay pretty accurate. may want to get it checked before buying tires, it could be off now and you could correct it with a slightly different size tire, Also consider most tires have around 11/32 or more of tread when new, so your speedo will read slightly different on worn vs new also. The factory also has a 15% margin of error to meet federal specs.

Take it to a shop that does calibration and get it checked or do it yourself with a stopwatch and highway mile markers, steady speed between markers and divide the number of seconds it takes into 3600 will give miles per hour, need a long, straight and flat section of highway to get a really good measurement, but this method is pretty accurate if you do it several times and average the results.

3rd method - borrow someone's GPS, that is the most accurate way to check actual speed.