What is a metric size equivalent to 32"

trekkindave · 07-07-2009, 10:22 AM

My pre-owned Jk came with 17" wheels the stock tires.. they have 30,000 miles on them and I want to upgrade in stead of replace with the factory tire.

I want to put the biggest tire I can get on the truck without going into a lift. The chart says that I can do a 32" tire without rub without a lift, but I am having a hard time finding the proper metric sizes to know what tires are available...

I think i remember seeing something like a 270-65-17 that was 31.6 inches in diameter.

Im looking for an aggressive looking AT with good street manners since I unfortunately dont wheel anything harder then a flat beach. So I am pretty sure I am going to get the BFG AT's....

Again.. I am looking for the biggest Metric size, or size options for a JK unlimited with 17 inch wheels and no lift that do not stick too far out the side of the truck.

bunkrdfool · 07-07-2009, 10:24 AM

255/75/17 are the bf goodrich m/ts that the rubi's come with.

abock33 · 07-07-2009, 10:27 AM

^ what he said. Their on my x also.

**Hilldweller** · 07-07-2009, 10:52 AM

Here's a great tire size calculator:
http://www.1010tires.com/TireSizeCalculator.asp?action=submit&reset=yes

You sound like you'll like a 275/70-17. Just a little bigger around and a bit wider than a stock 32".
If you want the J8 military tire, a BFG KM2 255/80-17 will fit and be a 33" for you.

trekkindave · 07-07-2009, 11:03 AM

Im looking for more of a AT tire similar to the BFG All Terrains.. from what tire rack is showing me.. they are not offered in a 275/70-17 or a 255-80-17

**Hilldweller** · 07-07-2009, 12:23 PM

Quote:

Originally Posted by trekkindave

Im looking for more of a AT tire similar to the BFG All Terrains.. from what tire rack is showing me.. they are not offered in a 275/70-17 or a 255-80-17

Find the tire you like and check the manufacturer's website to see if it's available. Sometimes Tire Rack and Discount Tire Direct might not list the tire.

Cooper Discoverer ST, Goodyear Wrangler MTR w/Kevlar, Goodyear Wrangler Silent Armor, Firestone Destination A/T, Mastercraft Courser C/T (Cooper) --- all come in 275/70-17.

If you got a set of spacers for your wheels, you could run 285/70-17 ---- that would give you a kazillion choices more.

That1guy · 07-07-2009, 01:31 PM

Go with a 265/70/17. Thats what on my ram and I think they are a 32 tire.

If you want an aggresive looking tire that is great on the road, go with the dick cepek FC II's. My good friend runs them on two different jeeps and they are great. They wear good and the do well on the street and can still play.

**Hilldweller** · 07-07-2009, 01:45 PM

Quote:

Originally Posted by That1guy

Go with a 265/70/17. Thats what on my ram and I think they are a 32 tire.

If you go out with a tape measure I think you'll find that it's not even a 31" tire.

The 255/70-18 stock tire on the Sahara is just a little over 31". The 265/70-18 that I put on to replace it was still under 32" but the manufacturer said it was 32.6". The 285/75-16 tire I'm running now is 32 7/16" and the manufacturer claims that it's 33.1".

Tire sizes lie. Yardsticks tell the truth.

That1guy · 07-07-2009, 02:13 PM

Quote:

Originally Posted by Hilldweller

If you go out with a tape measure I think you'll find that it's not even a 31" tire.

The 255/70-18 stock tire on the Sahara is just a little over 31". The 265/70-18 that I put on to replace it was still under 32" but the manufacturer said it was 32.6". The 285/75-16 tire I'm running now is 32 7/16" and the manufacturer claims that it's 33.1".

Tire sizes lie. Yardsticks tell the truth.

According to the tire calculator its a 31.6. Meh, its close

gpb · 07-07-2009, 02:33 PM

This isn't rocket science (or shouldn't be).

Given any tire spec in the form of "Width / SidewallRatio - Rimsize" the nominal diameter will be Rimsize + ( Width x SidewallRatio / 50 )

So for a 265/70-17 you start by converting 265mm to inches ( 265mm / 25.4 mm per inch = 10.43").
Then it's 17 + ( 10.43 x 70 / 50 ) = 17 + 14.6 = 31.6.

These measurements don't account for the tire being on a vehicle -- obviously the vehicle's weight on the tire will squish it down some. Measuring from the ground to the top of the tire will give you a different tire diameter than measuring front to back. Which is correct?

greenjkrescue · 07-15-2009, 09:33 PM

This may sound stupid, but how do you figure out the width?

**Hilldweller** · 07-16-2009, 06:29 AM

Quote:

Originally Posted by greenjkrescue

This may sound stupid, but how do you figure out the width?

it's printed on the tire....
The 285 of 285/75-16 means 285mm wide, 75% of that in sidewall height, on a 16" wheel.

ricku · 07-23-2009, 09:15 AM

According to the BFG website their LT285/70R17 AT tire is 32.70" in diameter. I bet that will work (that's what I'm planning to do also).
Let us know what you finally come up with.

DominicR · 07-23-2009, 09:27 AM

Don't know if this helps any but I put this formula in an excel spreadsheet when I was shopping for tires. Sub in different tire width, sidewall size, and rim size and it will calculate the entire tire size.

Current Tire (Stock)
225 Width in millimeters
/25.4 Millimeters per inch
8.86 Inches of tire width
x0.75 % of sidewall size
6.64 Inches of tire width for sidewall
x2 For two sides
13.29 Total tire inches on sidewall
+17 Rim Size
30.29 Tire Height

gmfcma · 12-12-2009, 07:56 PM

dont know if this will help you or not, but BFG just put out their 275/70-17.
i just ordered them on tire rack.

07-07-2009, 02:33 PM	#10
gpb Registered User Join Date: Nov 2008 Location: GA Posts: 305 Profile Gallery Classifieds My Jeeps	This isn't rocket science (or shouldn't be). Given any tire spec in the form of "Width / SidewallRatio - Rimsize" the nominal diameter will be Rimsize + ( Width x SidewallRatio / 50 ) So for a 265/70-17 you start by converting 265mm to inches ( 265mm / 25.4 mm per inch = 10.43"). Then it's 17 + ( 10.43 x 70 / 50 ) = 17 + 14.6 = 31.6. These measurements don't account for the tire being on a vehicle -- obviously the vehicle's weight on the tire will squish it down some. Measuring from the ground to the top of the tire will give you a different tire diameter than measuring front to back. Which is correct?

07-23-2009, 09:15 AM	#13
ricku Registered User Join Date: Oct 2007 Location: Kalida, Ohio Posts: 109 Profile Gallery Classifieds My Jeeps	According to the BFG website their LT285/70R17 AT tire is 32.70" in diameter. I bet that will work (that's what I'm planning to do also). Let us know what you finally come up with.