New rims & Spedometer read out - Toyota Nation Forum : Toyota Car and Truck Forums

unioncorps · 09-04-2004, 08:46 PM

Hey everyone,

Just a quick question about getting new rims. I have the 04 Corolla S with 15" rims and stock tires (195/65/15). I want to get new 17" rims and 215/45/17 or 215/40/17 tires. Also I'm doing a 1.25-1.5" drop on my car too.

Now, I've heard from different people that by changing the tires and rims the read out on the spedometer will be off. I spoke with the guy at the rim store and he said the 215/40/17 tires are the recommended ones for the rims I wanted and he said that the spedometer should work fine... Is he BSing me? On the site http://www.miata.net/garage/tirecalc.html, I calculated some of the different sizes and it was +/- .1 to 3 mph off from the stock.

If any of you have the same car as I do and have your rims changed, does your spedometer read out correctly? If I choose the 215/45/17 tires (assuming it'll fit on the rims), then according to that site, if the spedometer reads 60 mph, I'm actually traveling at 59.1. If I choose the other ones and if the spedometer reads 60 mph, I would be really going ~57 mph...
What do you guys do about this?

Thanks a bunch!!

lou8337 · 09-12-2007, 01:30 AM

i've herd the same thing but, i think theres some kind of tollerence but not sure what it is. i'm sure most cars probably differ from each other. i'm sure there some kind of chart or something if not go to another tire store or 2 and c what they say

trancedcorolla · 09-12-2007, 08:39 AM

If you're really worried about it, just do what I did and buy a GPS. They tell you how fast you're going.

***REN69*** · 09-12-2007, 10:14 AM

I don't have the direct link right now, but if you google "tire size calculator" it will give you links to this tool, enter the original size and then the new tire size on your car and it will calculate for you how much your speedo is off with the new size.