Rim Sizes

[reddragon]

I have heard from alot of people the rim sizes affect the speedometer. I went to a rim shop and he told me there would not be a change but alot of people have told me there is a huge difference can anyone help me.

[AGT]

Originally posted by reddragon@Feb 12 2005, 08:20 PM
I have heard from alot of people the rim sizes affect the speedometer. I went to a rim shop and he told me there would not be a change but alot of people have told me there is a huge difference can anyone help me.
It all depends on the diameter of the final wheel and tire setup. Like my 16s with 50 series that came stock were a 25.2 inch diameter whereas my 18s with 40s were 25.27. Not much difference means everything is fine but if you get a 17 with 40s it could be off a little.

[reddragon]

how off would it be

[AGT]

50 miles per hour or so :lol: Nah so little it wouldn't matter...if its speeding you are worried about than its your own ass for that anyways. If its mileage you are worried about then dont drive a car. Driving is a privelage not a right haha

[Grouch]

here's a handy dandy little tool to figure out how off it will/could be

Tire size/Speedo Error calculator:
http://www.miata.net/garage/tirecalc.html

[Spilner521]

I have 15" stockers with 215/60-15 tires and upgraded to 18's with 225/40-18 tires.

15" overall height = 25.2"
18" overall height = 25.1"

at 60 its off by .2 mph. not something to worry about if you ask me. i went by one of those radar signs the cops set up on a side street. when the car said i was doing 45, the sign said i was doing 45 (while also telling me to slow down :D)

[Redog]

Originally posted by AGT+Feb 12 2005, 08:28 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (AGT @ Feb 12 2005, 08:28 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-reddragon@Feb 12 2005, 08:20 PM
I have heard from alot of people the rim sizes affect the speedometer. I went to a rim shop and he told me there would not be a change but alot of people have told me there is a huge difference can anyone help me.
It all depends on the diameter of the final wheel and tire setup. Like my 16s with 50 series that came stock were a 25.2 inch diameter whereas my 18s with 40s were 25.27. Not much difference means everything is fine but if you get a 17 with 40s it could be off a little. [/b][/quote]
17's with 45's is better.

the 40's are for 18's

Good rule of thumb, plus size one inch, decrease the sidewall by 5

225/50/16's = 235/45/17's

(althought 225 is the widest on an Alero but some guys have 235's on thier cars

[BigJon34]

Originally posted by Grouch@Feb 12 2005, 06:04 PM
here's a handy dandy little tool to figure out how off it will/could be

Tire size/Speedo Error calculator:
http://www.miata.net/garage/tirecalc.html
That webpage should be stickied or maybe we can get the javacode to put on aleromod. It would be very useful considering the number of times this question is asked in the forums. I think it was like my very first post.

[Grouch]

it's in the Wheel/Tire Info FAQ thread. But no one ever looks at the FAQ's. If we started stickying all the Common and FAQ questions around the site the first half of every page would be stickies.

[BigJon34]

What about imbedding their code into the site?

[Oldsman]

Originally posted by Redog@Feb 13 2005, 06:31 PM
(althought 225 is the widest on an Alero but some guys have 235's on thier cars
235's...................................hahahahaha haha....................weak