Ok I am buying the Rims today, I have been shopping for tires as well. Well I have people telling me I cannot run certain sizes, my stock size is 225x70x15 I want to run a little wider tire. What do you guys recommend? The rims will be 15x8. I was looking at a 215x60x15 but was told this going to be too small. So I need to know how the measurements are taken please.

 

Confused...you said you want wider, but you went smaller???

The first number when dealing with P metric tires, example: P225/70R15, the first number (225) is the width of the tire in millimeters (divide by 25.4 to get inches). So 225/25.4=8.85" So the tires is almost 9 inches wide. Next you have the aspect ratio (70). This is a percentage of the width that makes up the sidewall height of the tire. So 70% (or .70) of 8.85" is the height of one sidewall. .7x8.85=6.195" Then since a tire is round (somewhat) multiply by 2 because there are two sidewalls when going from the bottom to the top. So 6.195"x2=12.39". Now add the rim diameter (15") to get the total diameter of the tire. 12.39"+15"=27.39"

Your second choice of 215/60/15 would be 8.5" wide (narrower) and 25" tall. Ideally you want to stick to the original tire's overall diameter. But you do see a lot of offroaders going to larger diameter tires. If you want wider tires but lower profile sidewalls, usually you want to get bigger rims. Since you already are getting 15's, you may want to go with something like 235/65/15 (27" OD 9.25" W) if it exists or maybe 245/60/15 (26.6" OD 9.65" W) if it will fit with out rubbing...not sure if you have the equivilent to an XLT or what?

 

Confuzzled now. LOL I will have to read this several times to get it.

Okay my stock rims are 15x5.5 or 15x6.5 I do not remember but the rims I ordered are 15x8 so reading your post above I could safely and still look good with a 235/65/15 or a 245/60/15?

 

So on this ebay listing http://cgi.ebay.com/ebaymotors/ws/eB...category=66473

it says in the table

P245/60R15 tire size
100 T service desc
440 A B UTQG
7.00 - 8.00 Approved Rim Width
7.00 Measured Rim Width
9.47 Section width (Explain This please)
26.55 Overall Diameter
8.00 Tread width (Explain this)
1753 Max Load
10.5 Tread Depth

Sorry for the long post but I really am trying to understand and hopeing to know
if these tires will fit my truck and my new rims.

 

Stock rims are 15x7.

What size rim is a piece of information the tire manufacturer provides. Pick a size you want and look to see if they recommend it for your rim. IT IS MANUFACTURER SPECIFIC in many cases and has to do with sidewall flex and other factors.

Some time spent on a manufacturers tire chart should get you what you need. You can usually find the info on their website.

 

Well, since you are getting 15x8 rims...this (7.00 - 8.00 Approved Rim Width) means they will fit the rims. Whether they fit the truck is another story. Hopefully someone with an XLT can chime in.

9.47 Section width (Explain This please)
Section widthwould be the width of the tire from sidewall bulge to sidewall bulge. This is a little wider than the actual tread width

8.00 Tread width (Explain this)
Tread width would be the width of tread on the tire...it varies as does section width based on the width of the rim you are using. See in their example they said 7.00 Measured Rim Width. So all these width measurements are actually with a 15x7. Your 15x8's should make things a little wider i think.

So if you were to look at the tire from the top (if it were on the truck) you would see a width of tread, in this case 8" on a 15x7. And sticking out past the tread would be some sidewall and that width is the section width, in this case 9.47" on a 15x7.

 

This should help answer all your questions man, google is great

http://www.miata.net/garage/tirecalc.html

 

In case you ever need to know tire diameter, and you don't have the internet handy, remember this number: 1270

You can take any metric sized tire and it has three numbers in it, like 265-70R15 for instance.

Multiply the first two numbers, divide by 1270, and add the third number to get the tire diameter in inches.

265 x 70 = 18550

18550 / 1270 = 14.6

14.6 + 15 = 29.6 (about a 30" tire)

Or: 265 x 70 / 1270 + 15 = 29.6

That works for any metric size tire, always. That way you need only a pocket calc or a piece of paper if you can remember 1270.

 

Hell, I can't even use that...

 

Mike, I have known what the tire sizes meant, but I have never actually taken the time to break down the actual height of my tire using this method. I just wanted to thank you. I figured up my old tires and wheels and the new ones to see the difference I had in over all height and it actually makes me feel pretty good with the amount of lowering I am doing to my truck. My old tires were 27.39" and the new ones are 25.68". So the 2/3 lowering kit I am putting on my truck I think will give it a nice look while making it also 'look' stock. Slammed trucks are cool, but I still need some practical use out of mine. Anyways, thanks for opening my eyes.

 

I really hope you are kidding.

 

i have a 15x8 inch rim as well and i went for the biggest tire i can fit on a 4x2 ranger with no lift. After talking to many tire companies they said 30x9.5x15 are the biggest so i went with that and they fit good. only peoblem was it was rubbing one one side when i turned the weel all the way. so i just cut part of the mud flap off an i was good to go.
Why they only rub on one side and i have an inch gap on the other?? i donno. if anyone knows what might be wrong i could use some help.