I was reading some of the topics here bigger wheels and how it effects the speedo. i want to get 18" rims...how can i go bigger w/o affecting the speedo? (as far as offset, type of tire, etc.)

anyone got any suggestions for brands with 18" chrome deep dish


what if i were to go with 20"

what would be the type of tire and offset and all the other mumbo jumbo


thanks

 

Speedo will be off if you get anything bigger than the stock wheel and stock tire size.

(More knowledgeable people correct me if Im wrong)

 

i have 19's and my speedo is practically dead on...i have been clocked at highway speeds and only about 3 mph off...as far as offset goes i have a 42mm offset on my rims and they look really nice, my tire size is a 215/35/19, i had slight rubbing issues at stock height at absolute left and right but thats it and dont have that problem anymore with the drop...

i would stay away from anything bigger than a 19 inch rim, i mean 20's look cool as crap but they are just too big for the box, i know there has to be a lot of rubbing issues with dubs.

 

Um, yeah, that's pretty much wrong.

You can go to just about any size wheel you want, as long as you buy a tire that's the same diameter/height as the stock one.
Walk with me...
The stock tire on an xB is a 185/60-15, obviously on a 15" diameter wheel. That 185/60 tire diameter (height) is approximately 23.7".
As someone else mentioned, 20s are a bit too wild for the little xB, so let's stick with your original thought of an 18 incher.
When up-sizing rims, you usually want a beefier width tire, so let's go with a 205. A 205/35-18 is almost identical in diameter to the stocker at 23.6". At a difference of less than only .4%(!), this will keep your speedo just about exact to what your stock tires' reading would be.
See the trick to buying smart?

 

lol cool thanks alot. on website i look at, they suggest a 215 instead of a 205 will it be a difference of .4% either way???

 

here is a link so you can play with tire sizes.
first start with the stock tire size the see the overall height.
then just play with the numbers to find a size you want and keep it as close to the same height as posible.
only fill in the first 3 blanks.

http://www.juric.org/mopar/tools/tirecalc.php

oh and make sure that size is even made
you know like a 195/30/19 is 23.6 inches tall but nobody makes a tire that size.

 

Im going to go to the corner to cry now

Im a Kiniesology major not a math major

Like I said depends on tire and wheel choice

 

Well...no, but close enough.
Let me take it a bit further, if you don't mind - and I'm not boring the crap out of anybody.
I'm going to assume that you aren't familiar with what all those numbers mean in tire sizes, so this may help you get a better idea about what you're talking about, and shopping for.
Starting withe stock tire, 185/60-15; this is actually a simplified version of the entire number, which can be as long as say "P185/60HR-15".
The "P" just means its a Passenger car tire, not a truck type.
The "185" (or 205, 215, etc.) is the cross-section width of the tire in millimeters, or with this tire, about 7 1/4". This is where a lot of folks misunderstand the numbers: this is the cross-section, measured from sidewall to sidewall, NOT the tread width!
The "60" (or 50, or 45, etc.) is the aspect ratio of the tire, or the sidewall height, represented in a percentage. In other words, the sidewall on this tire is 60% as tall as the tire is wide. This is how you figure a tire's diameter/height - so 60% of 185mm = 111mm. 111mm x 2 (two sidewall heights, since as you look at the tire from the side, you'd have one sidewall height at the top, and one at the bottom) = 222. Now, you've got a 15" wheel between the two sidewalls, right? OK, 15 inches x 25.4 (to convert it to metric) = 381mm. That 381mm + the 222 from the two sidewalls = 603mm. If you convert that 603mm back to American standard, you've got 23.7 inches (just like in my first post!).
The next letter, "H" (or T, Z, etc.) is the speed rating of that particular tire. All tires have this. Its the maximum speed rating at which the tire has been tested to be able to run continuously at. There are charts to look this up on, as there is no formula to figure that out with. Obviously, the higher the rating, the higher performance the tire.
The "R" just means it's a radial tire, which just about all are these days anyway.
Finally, the "15" (or 16, 18, etc.) is the diameter of the only wheel the tire will fit on.
Sleeping yet?
I hope not...I still haven't answered your question!

If you use the above formula, you can figure out yourself the answer to the 215 vs. 205 dilemma...

Ok, OK - I'll help. the 215/35-18 is about 23.9" , which is only slightly taller than the stock 185/60-15 at 23.7", so you'll be fine. That will only affect your speedo by about .8%, which at 60mph is only about 1/2 a mile an hour - you'll never notice it.

Be sure to post pics when you get 'em! :D

 

or you could just use this link
http://www.juric.org/mopar/tools/tirecalc.php
and save yourself from all the crazy math.

 

True - that's a pretty cool site.
But I thought it might be a good idea for the guy to actually know what he was talking about, too...

 

Nice info man. I couldn't have explaned it any better myself.

But really, would you really worry about being 5 mph off? The only way this would be a concern, is if you drove a road that no one else did for you to pace with, and some idiot cop sat on that deserted road waiting for the one guy to drive by speeding, to give him a ticket for a measely 5MPH. So unless you and the cop are the only ones that live on this deserted road, I wouldn't worry about it. I ahve had cars with no speedo at all. I just pace with the traffic.

 

yah i agree.
don't just give him a fish teach him to use a fishing poll.

i just like taking the easy way when it comes to that kind of math