New Tires this week, need advice/opinions - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 08-20-2012, 09:08 AM   #1
Jeeper
 
Join Date: Mar 2012
Location: Locust, NC
Posts: 41
New Tires this week, need advice/opinions

Hello everyone! I am getting a new set of tires this week on my stock 2003 TJ Wrangler. I have decided on the Firestone Destination A/T's but not on the size. I am totally stock and I love the fact that I am getting 20+ mpg. I would like to get the Jeep up a little but I don't want to mess with my fuel economy. The stock size is 30x9.5 and I am considering the 31x10.5. Which one should I get? Do any of you have pics. of a stock TJ with 31x10.5 tires so I can see how they look?
Thanks,
Michael

mismith is offline   Quote Quick Reply
Old 08-20-2012, 09:13 AM   #2
Jeeper
 
Join Date: Feb 2012
Location: Shillington,PA
Posts: 381
If you are somehow getting 20 plus MPG, and you like it that way, I wouldnt change a thing ( tire size or type)...just my 2 cents.

JustinCHorst is offline   Quote Quick Reply
Old 08-20-2012, 09:36 AM   #3
Jeeper
 
Join Date: Mar 2012
Location: Locust, NC
Posts: 41
I check it religiously and yes I get between 20 and 20.4 every fill up. The worst I ever got was 19.5. I don't know why people get so surprised at this. I have 2 other co-workers with different year stock TJ's like mine with 4.0 and 5 speed. We all get 20 mpg, heck they talked me into buying one. I also have a friend with a 2009 stock 2 door with the v6 and 6 spd. and he swears he consistantly gets 21+ mpg with his in daily driving and even higher on the highway.
Michael
mismith is offline   Quote Quick Reply
Old 08-20-2012, 09:39 AM   #4
Jeeper
 
Join Date: Feb 2012
Location: Shillington,PA
Posts: 381
Im not doubting you...maybe you have a light foot, flat roads, and ethanol free fuel (which helps)...what I am saying is a larger more agressive tire of any kind will only hurt your MPG.
JustinCHorst is offline   Quote Quick Reply
Old 08-20-2012, 09:55 AM   #5
Jeeper
 
Join Date: Mar 2012
Location: Locust, NC
Posts: 41
Well I do drive conservatively but we live in a very hilly area. The previous owner put these little el-cheapo 225/? skate board tires on it. I hate them and they look stupid on a Jeep. My other buddies mentioned above are running A/T's. One guy is running the stock style Good Year Wranglers and the others have Bridgestone Duelers. The 30x9.5's are gonna give me another 1 inch taller than the ones on there now. Is 1 inch really gonna make a difference in mpg? I would think it would do better because the little tires on there now seem to have it screaming for another gear once up to speed.
mismith is offline   Quote Quick Reply
Old 08-20-2012, 10:06 AM   #6
Jeeper
 
Crazyflyingplastics's Avatar
 
Join Date: Jan 2012
Location: Austin
Posts: 531
Images: 2
Quote:
Originally Posted by mismith View Post
I check it religiously and yes I get between 20 and 20.4 every fill up. The worst I ever got was 19.5. I don't know why people get so surprised at this. I have 2 other co-workers with different year stock TJ's like mine with 4.0 and 5 speed. We all get 20 mpg, heck they talked me into buying one. I also have a friend with a 2009 stock 2 door with the v6 and 6 spd. and he swears he consistantly gets 21+ mpg with his in daily driving and even higher on the highway.
Michael
People are surprised because most jeeps get around 15 mpg. You can probably put 31 on there, but it would be a tight fit. Most do a 2 inch lift for 31s. If you don't plan to hit the trails, 31 would be fine.
Crazyflyingplastics is offline   Quote Quick Reply
Old 08-20-2012, 02:29 PM   #7
Jeeper
 
Join Date: Feb 2012
Location: Shillington,PA
Posts: 381
Quote:
Originally Posted by mismith View Post
Well I do drive conservatively but we live in a very hilly area. The previous owner put these little el-cheapo 225/? skate board tires on it. I hate them and they look stupid on a Jeep. My other buddies mentioned above are running A/T's. One guy is running the stock style Good Year Wranglers and the others have Bridgestone Duelers. The 30x9.5's are gonna give me another 1 inch taller than the ones on there now. Is 1 inch really gonna make a difference in mpg? I would think it would do better because the little tires on there now seem to have it screaming for another gear once up to speed.
Its really impossible to say how it will reflect ( for me to figure out), but larger surface area, rotational mass, and greater friction will reduce your MPG...at worst 1-2 mpg on avergae...Im guessing.... but I would plan on a loss....personally I would do it as I know it will look much better then your current setup, just dont be dissapointed if you lose some mpg.....was your speedo corrected for your small tires?...if not you could be logging more miles and therefore slightly inflating your current MPG numbers....you will have to take in account speedo changes when you size up as well.
JustinCHorst is offline   Quote Quick Reply
Old 08-20-2012, 02:47 PM   #8
Jeeper
 
Join Date: Aug 2012
Location: NE Texas
Posts: 104
I have 31x10.5x15 Cooper Discoverer A/T3's and still get 20mpg if I don't run too fast. They are on American Racing wheels that were on the Jeep when I bought it. I don't have any clearance issues but have a 2" lift I am installing this weekend.
TxkTJ is offline   Quote Quick Reply
Old 08-20-2012, 03:32 PM   #9
Jeeper
 
Join Date: Mar 2012
Location: Locust, NC
Posts: 41
well I checked and my tires now are 225/75/15 and approx. 28.5" in diameter. I had the smallest tires of my co-workers and friends. I just went by and ordered my 31x10.50x15's! I know it will look better and if I lose mpg's then so be it. Now do I have to re-gear my speedo to be correct? If so, then how do I do it?
Michael
mismith is offline   Quote Quick Reply
Old 08-20-2012, 03:35 PM   #10
Jeeper
 
Rolf's Avatar
 
Join Date: Sep 2011
Location: South Africa
Posts: 941
Quote:
Originally Posted by TxkTJ View Post
I have 31x10.5x15 Cooper Discoverer A/T3's and still get 20mpg if I don't run too fast. They are on American Racing wheels that were on the Jeep when I bought it. I don't have any clearance issues but have a 2" lift I am installing this weekend.
I have 32"s and on a good day with carefull driving I don't even get 12mpg.
__________________
2003 Wrangler Sahara 4.0 42rle D30/D44
Front: 2" BDS coils + JKU shocks
Rear: 2" BB + Zone Nitro shocks
Zone 1.25" BL + 1" MML, UCF LoPro
32" BFG AT on 16" Racing Hart
Ramsey Pro Plus 6000, IPF 900s 130W
Rolf is offline   Quote Quick Reply
Old 08-20-2012, 04:29 PM   #11
Jeeper
 
svtyone's Avatar
 
Join Date: Oct 2011
Location: el cajon,ca
Posts: 102
Wow 32's and that bad of mirage? I'm thinking you have others issues for bad gassed mirage. I have 31's and get 15-19. My dad has an 05 with 31's and he gets about 19-22. That's the six cylinder of course.
__________________
get your s@#t dirty
svtyone is offline   Quote Quick Reply
Old 08-20-2012, 04:32 PM   #12
Jeeper
 
WeekenderATX's Avatar
 
Join Date: Jun 2012
Location: Austin, TX
Posts: 563
31x10.5 duratracs on 2.5in RC lift. Rubbed at full turn. Fixed by adding washers to steering stops. Easy.

Attachment 152127
WeekenderATX is offline   Quote Quick Reply
Old 08-20-2012, 07:10 PM   #13
Jeeper
 
Join Date: May 2011
Location: Sampson County
Posts: 36
I currently have 30 x 9.5 x 15 tires on my TJ and have gotten between 18-20 MPG Hwy; city Hwy combined 16-18. I get the best mileage using the cruise control at 65-67 MPH on the interstate. Have 5spd and 4.0 with 373 gears. I checked the odometer against a GPS for 100 mile trip and was less than 1 mile difference. The first 2 tanks of gas after buying Jeep mileage was 14-16 MPG; checked air pressure in tires and found to be at 15 PSI. I found between 30-35 PSI gave me the best mileage. I'm not sure how much difference 31 x 10.5 tires would affect your mileage but 30" tires may get you 19-20 MPG.
hrun is offline   Quote Quick Reply
Old 08-20-2012, 07:25 PM   #14
Jeeper
 
JVLemur's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 4,478
I have 31x10.5s on my stock 01 TJ. I like the look of it, no rubbing and rides well, only thing is I have stock 3.07 gearing and my gas is between 14-15mpg at very best, but I don't mind.
Here's a pic.
__________________
Don't follow the Hype, follow your Heart.
JVLemur is offline   Quote Quick Reply
Old 08-20-2012, 07:34 PM   #15
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,491
Images: 2
A stock unlifted TJ works fine with a 31x10.50 size tire. That is roughtly the equivilent size to the metric size tire that comes on the same unlifted height Rubicon.

At the most, and only if you happen to get a little minor inside tire sidewall rubbing when you turn the steering wheel all the way to the left or right, you may need to add a pair of two cent washers underneath both steering stop bolts. If needed, here's how to do that... Jeep Steering Stop Adjustment
__________________
Remember that having a different opinion doesn't also require one to be a jerk when expressing it.

When you have a choice, buy American.

Jerry Bransford is offline   Quote Quick Reply
Old 08-20-2012, 09:23 PM   #16
Jeeper
 
Join Date: Mar 2012
Location: Locust, NC
Posts: 41
What about my speedometer being off with the 31's? Do I need to change anything for it to be accurate?
mismith is offline   Quote Quick Reply
Old 08-20-2012, 09:31 PM   #17
Jeeper
 
JVLemur's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 4,478
Quote:
Originally Posted by mismith
What about my speedometer being off with the 31's? Do I need to change anything for it to be accurate?
Every time I check with my gps I read +5mph but its also downhill, I'll check again on my way home and I'll let you know
__________________
Don't follow the Hype, follow your Heart.
JVLemur is offline   Quote Quick Reply
Old 08-20-2012, 10:09 PM   #18
Supporting Member

WF Supporting Member
 
Water Dog's Avatar
 
Join Date: Mar 2011
Location: Roseville, CA
Posts: 5,123
Images: 11
Quote:
Originally Posted by mismith View Post
What about my speedometer being off with the 31's? Do I need to change anything for it to be accurate?
Here's a chart to figure the number of teeth you need on a new speedo gear. Jeep Speedometer Gears for Wrangler TJ, YJ, Cherokee XJ, Grand Cherokee ZJ Once you know that just go to Quadratech or whoever else sells them and order the gear with the correct number of teeth....10 minute install. Here's a hint: wait until you get your new tires mounted then go out and physically measure the height instead of depending on what the tire size tells you.

Also remember that if you are running bigger tires and haven't recalibrated your speedo, your mileage calculations won't be right as well.
Water Dog is offline   Quote Quick Reply
Old 08-20-2012, 10:24 PM   #19
Jeeper
 
Join Date: Mar 2012
Location: Locust, NC
Posts: 41
How do you recalibrate the speedo? Man, nothing can ever be simple eh?
mismith is offline   Quote Quick Reply
Old 08-20-2012, 10:31 PM   #20
Jeeper
 
JVLemur's Avatar
 
Join Date: Apr 2012
Location: California
Posts: 4,478
Quote:
Originally Posted by mismith
How do you recalibrate the speedo?
New speedo gear, water dog posted a link, also I checked for you, on a 30 mile trip, mostly highway, the speedometer reads speed fairly accurate up until 50mph, that's when it changes, I was doing 60-65mph constantly and my speed was between 64-70mph on my gps which means that theres about a 5mph difference, so my speedometer is reading
-5mph not +5mph sorry.
__________________
Don't follow the Hype, follow your Heart.
JVLemur is offline   Quote Quick Reply
Old 08-20-2012, 11:07 PM   #21
Jeeper
 
Throde's Avatar
 
Join Date: Aug 2012
Posts: 39
Quote:
Originally Posted by svtyone
Wow 32's and that bad of mirage? I'm thinking you have others issues for bad gassed mirage. I have 31's and get 15-19. My dad has an 05 with 31's and he gets about 19-22. That's the six cylinder of course.
I have 05 unlimited 6 speed manual and lucky to get 16 mpg with 30s
Throde is offline   Quote Quick Reply
Old 08-21-2012, 09:35 AM   #22
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,491
Images: 2
Quote:
Originally Posted by mismith View Post
How do you recalibrate the speedo? Man, nothing can ever be simple eh?
Actually it is very simple to recalibrate the speedometer which can be done in 5 minutes with nothing more than a 1/2" wrench. The speedometer gear just snaps into place.

Here's how... Changing Your Jeep Speedometer Gear

__________________
Remember that having a different opinion doesn't also require one to be a jerk when expressing it.

When you have a choice, buy American.

Jerry Bransford 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 05:40 AM.



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