Tires size and weight advise - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 12-14-2013, 04:32 PM   #1
Jeeper
 
Ajax333333's Avatar
 
Join Date: Dec 2010
Location: Gilbert, AZ
Posts: 415
Tires size and weight advise

Sorry for another tire question. I searched, but can't find what I'm looking for. (sp in title= advice!!)
I accidentally posted this in the TJ sections so I'm re-posting here.

I have a 2007 JKU with a factory tire carrier. Right now I run 285/70/17 BFG AT's. They weigh 59lbs and are 32.8" according to Tirerack.com specs. I need new tires. The other I'm considering have the following specs:

Mickey Thompson 285/70/17: 59lbs, 33"
Duratracs 285/70/17: 59lbs, 32.8"
Duratracs 315/70/17: 60 lbs, 34.4

I know there is a lot of talk about gears and such, but if a Duratrac 315/70/17 weighs as much as the BFG 285/70/17 do I have anything to worry about? I assume gas mileage would be about the same and it would drive about the same because the weight is the same (OK - 1lb different). Also I would think that he tire carrier would be OK since I have been running the BFG on there for a few years now. Am I missing something or do you think I would be OK?

For what it's worth I have an auto w/ 4:10 gears and a 2.5" lift

Ajax333333 is offline   Quote Quick Reply
Old 12-14-2013, 07:51 PM   #2
Jeeper
 
Join Date: Sep 2013
Location: Arizona currently
Posts: 210
Quote:
Originally Posted by Ajax333333 View Post
Sorry for another tire question. I searched, but can't find what I'm looking for. (sp in title= advice!!)
I accidentally posted this in the TJ sections so I'm re-posting here.

I have a 2007 JKU with a factory tire carrier. Right now I run 285/70/17 BFG AT's. They weigh 59lbs and are 32.8" according to Tirerack.com specs. I need new tires. The other I'm considering have the following specs:

Mickey Thompson 285/70/17: 59lbs, 33"
Duratracs 285/70/17: 59lbs, 32.8"
Duratracs 315/70/17: 60 lbs, 34.4

I know there is a lot of talk about gears and such, but if a Duratrac 315/70/17 weighs as much as the BFG 285/70/17 do I have anything to worry about? I assume gas mileage would be about the same and it would drive about the same because the weight is the same (OK - 1lb different). Also I would think that he tire carrier would be OK since I have been running the BFG on there for a few years now. Am I missing something or do you think I would be OK?

For what it's worth I have an auto w/ 4:10 gears and a 2.5" lift
Weight is not the primary thing to be concerned about when going to larger tires. It's where the weight is located at that makes the difference. Going to a 34.4 inch tire from a 32.8 inch tire, even if the weight is identical, is going to make a marked difference in acceleration and fuel economy because it essentially changes your gearing, thus reducing the amount of torque being applied where the rubber meets the road. This means you will need more throttle to accelerate as hard as you used to, which means reduced gas mileage. Additionally, the extra width of the tire introduces more rolling resistance as well as aerodynamic drag (both on the tire as well as extra air getting under the jeep which increases drag as well). You'll lose a MPG or so and your acceleration will suffer a bit. A re-gear solves the acceleration issue but there's no way around the loss of MPG.

MHShale is offline   Quote Quick Reply
Old 12-14-2013, 10:32 PM   #3
Jeeper
 
bengen1's Avatar
 
Join Date: Sep 2011
Location: St. Louis County
Posts: 592
Fwiw 285/70/17 duratracs are 54 lb not 59
bengen1 is offline   Quote Quick Reply
Old 12-15-2013, 05:59 AM   #4
Jeeper
 
Faith and Trust's Avatar
 
Join Date: Aug 2013
Posts: 258
My advice is get the tire you want.
Faith and Trust is offline   Quote Quick Reply
Old 12-15-2013, 06:40 AM   #5
Jeeper
 
The Green Monster's Avatar
 
Join Date: May 2013
Location: NC
Posts: 199
Weight located further away from the axis of rotation yields great rotational inertia. As MHShale said, even with the two tires being approximately the same weight, the larger diameter tire will cause more strain on your acceleration and therefore gas mileage in situations where you are not traveling at a constant speed.
__________________
Brian
2013 JKUR
The Green Monster is offline   Quote Quick Reply
Old 12-15-2013, 08:19 AM   #6
Jeeper
 
WhiskeyMike's Avatar
 
Join Date: Aug 2012
Location: Austin, TX
Posts: 833
I just went from 33x15x12 duratrac to 315 duratracs. The MPG difference was negligible. So far about .5 mpg difference. The acceleration is slower, but not so much I wouldn't do it again. I think the carrier is dependent on how you treat it. Lot of mixed reports. I'm swapping to new bumper with carrier.

Pick the one you want.
WhiskeyMike is offline   Quote Quick Reply
Old 12-15-2013, 08:56 AM   #7
Jeeper
 
Ajax333333's Avatar
 
Join Date: Dec 2010
Location: Gilbert, AZ
Posts: 415
Ok, good to know. I wasn't too concerned with MPG as I was with the carrier weight, though I have a 60 lb. on there now.
Ajax333333 is offline   Quote Quick Reply
Old 12-15-2013, 09:59 AM   #8
Jeeper
 
Old Dogger's Avatar
 
Join Date: May 2012
Location: Phoenix, Rattlesnake Country
Posts: 3,249
Two things to always remember are:
Taller tire, heavier tires, and heavier wheels will always impact your fuel economy, but will also have a negative effect on your BRAKING SYSTEM, also! It will take more distance to stop, and your brake pads will wear at a more aggressive rate!

I believe that your owners manual, will tell you what the max is for your carrier!
Old Dogger is offline   Quote Quick Reply
Old 12-15-2013, 10:07 AM   #9
Jeeper
 
Ajax333333's Avatar
 
Join Date: Dec 2010
Location: Gilbert, AZ
Posts: 415
Didn't think about braking. Good tip.
Ajax333333 is offline   Quote Quick Reply
Old 12-15-2013, 10:25 AM   #10
Jeeper
 
Old Dogger's Avatar
 
Join Date: May 2012
Location: Phoenix, Rattlesnake Country
Posts: 3,249
Quote:
Originally Posted by Ajax333333 View Post
Didn't think about braking. Good tip.
I don't want to get off of your topic, but I see that you are in Gilbert. I was a Manager for Hunter in Gilbert, "one of the largest contractors in Arizona", but am now retired, FYI!
Old Dogger is offline   Quote Quick Reply
Old 12-15-2013, 11:23 AM   #11
Jeeper
 
Ajax333333's Avatar
 
Join Date: Dec 2010
Location: Gilbert, AZ
Posts: 415
Oh cool. Nice to meet you. Once I get new tires I'm going to start wheeling more with my son. Maybe I'll see you out on the trails / runs.
Ajax333333 is offline   Quote Quick Reply
Old 12-15-2013, 12:07 PM   #12
Jeeper
 
Old Dogger's Avatar
 
Join Date: May 2012
Location: Phoenix, Rattlesnake Country
Posts: 3,249
Quote:
Originally Posted by Ajax333333 View Post
Oh cool. Nice to meet you. Once I get new tires I'm going to start wheeling more with my son. Maybe I'll see you out on the trails / runs.
I have a cabin up on the Rim, that is where I normally run..........
Old Dogger is offline   Quote Quick Reply
Old 12-15-2013, 06:03 PM   #13
Jeeper
 
rubisteph's Avatar
 
Join Date: Aug 2013
Posts: 377
Unless you have a diffrent than stock bumper at the back, the biggest the stock carrier will fit is 285/70-17. Any bigger and you wont be able to close the tailgate due to bumper clearance.

Unless you use a spare tire relocator. If you do that, you will add much more stress on the stock carrier due to the prying effect, doing exactly wbat you are trying to avoid right now!!!
rubisteph is offline   Quote Quick Reply
Old 12-15-2013, 06:14 PM   #14
Jeeper
 
JTPhoto JK's Avatar
 
Join Date: Jun 2011
Posts: 1,046
Images: 3
That depends on the tire. Many 35s are small enough to fit on the stock carrier and stock bumper with a 4.5" backspace wheel. I personally ran Duratracs and Xtreme M/T on the stock carrier. In our club one jeep has 35" mud grappler on stock carrier.
__________________
Jeff _(OIIIO)_

08 Black and Khaki JK Sahara Unlimited, Dual Tops, MyGig, Tow pkg, Trax-Lok Rear Diff,
Mods -- 3.5" Rock Krawler front springs, 2.5 TerraFlex BB, PitBull Rockers 35x12.50x17 on BlackRock Vipers, AEV Premium Bumper,
JTPhoto JK is offline   Quote Quick Reply
Old 12-15-2013, 06:43 PM   #15
Jeeper
 
rubisteph's Avatar
 
Join Date: Aug 2013
Posts: 377
Quote:
Originally Posted by JTPhoto JK View Post
That depends on the tire. Many 35s are small enough to fit on the stock carrier and stock bumper with a 4.5" backspace wheel. I personally ran Duratracs and Xtreme M/T on the stock carrier. In our club one jeep has 35" mud grappler on stock carrier.
Right, forgot about wheel offset, as I took for granted he was on stock wheels. However, the tire being further out must be a tailgate/ stock carrier killer. I believe anyone wanting to run bigger than 33s, should seriously consider the teraflex tailgate reinforcement brackets or other aftermarket carriers..... If I ever go bigger than 33 myself, I'd go with the AEV carrier for my 10A.
rubisteph is offline   Quote Quick Reply
Old 12-15-2013, 07:37 PM   #16
Jeeper
 
JTPhoto JK's Avatar
 
Join Date: Jun 2011
Posts: 1,046
Images: 3
Again it really depends.. On our rigs the 35" tire put less stress on the tailgate then a 33" would because the 35" tire actually sits on the bumper and bumper supports the weight and stops vibration.. Now a 35" on the stock carrier with an aftermarket bumper thats a different animal and I agree a tailgate support/reinforcement would be suggested.. For the record, we now run 35" Pitbulls and they do not fit on the stock carrier.
__________________
Jeff _(OIIIO)_

08 Black and Khaki JK Sahara Unlimited, Dual Tops, MyGig, Tow pkg, Trax-Lok Rear Diff,
Mods -- 3.5" Rock Krawler front springs, 2.5 TerraFlex BB, PitBull Rockers 35x12.50x17 on BlackRock Vipers, AEV Premium Bumper,
JTPhoto JK is offline   Quote Quick Reply
Old 12-15-2013, 10:27 PM   #17
Jeeper
 
Ajax333333's Avatar
 
Join Date: Dec 2010
Location: Gilbert, AZ
Posts: 415
Quote:
Originally Posted by JTPhoto JK View Post
Again it really depends.. On our rigs the 35" tire put less stress on the tailgate then a 33" would because the 35" tire actually sits on the bumper and bumper supports the weight and stops vibration.. Now a 35" on the stock carrier with an aftermarket bumper thats a different animal and I agree a tailgate support/reinforcement would be suggested.. For the record, we now run 35" Pitbulls and they do not fit on the stock carrier.
Your Jeep looks great. How long have you been running that setup on your stock carrier? That is kind of the look I'm going for.
Ajax333333 is offline   Quote Quick Reply
Old 12-15-2013, 11:38 PM   #18
Jeeper
 
JTPhoto JK's Avatar
 
Join Date: Jun 2011
Posts: 1,046
Images: 3
Quote:
Originally Posted by Ajax333333 View Post
Your Jeep looks great. How long have you been running that setup on your stock carrier? That is kind of the look I'm going for.
Thanks.... I ran that set up for about 3 years with no issues. After I got the Pitbulls I could no longer run the spare on the factory carrier.
__________________
Jeff _(OIIIO)_

08 Black and Khaki JK Sahara Unlimited, Dual Tops, MyGig, Tow pkg, Trax-Lok Rear Diff,
Mods -- 3.5" Rock Krawler front springs, 2.5 TerraFlex BB, PitBull Rockers 35x12.50x17 on BlackRock Vipers, AEV Premium Bumper,
JTPhoto JK is offline   Quote Quick Reply
Old 05-08-2014, 07:17 AM   #19
Jeeper
 
Rottiegirl's Avatar
 
Join Date: Aug 2012
Location: SW Pennsylvania
Posts: 22
Thanks to all who contributed. Changed from stock GY Wranglers (17") and stock wheels to Mickey Thompson MTZ, 285/70R17 on 17" American Racing wheels,no rubbing issues at all, at least on road. Haven't gone off-road yet. Thread was a lot of help in understanding wheel and tire issues. Now need a new tire carrier (and rear bumper, front bumper to match, lights, ......... ).

__________________

Rottiegirl
Rottiegirl is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 03:12 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC