Anybody Running 15.5 Tires on a 392?

[ohthatguy]

I got my 392XR last night and ordered some inexpensive 18x12 -44 wheels (Moto Metal MO962) because they weighed around 36 lbs (light vs the 55+ lb options I keep seeing) and Yoko Geolandar X-MT 38x15.5 tires (also the lightest I could find in the size).

From what I’ve seen on YouTube, some light trimming will be required to avoid contact. I don’t really have too many off-road opportunities where I am so this is an urban assault vehicle build (mall crawler) vs sonething that will see too much action off road.

Has anybody else run this size tire w/o a lift? Id love to see pics to tide me over for the week it takes my new set up to arrive.

Went with 36x15.5 Mickey Thompson Baja MTZ MT on 20x12 -44 wheels, no lift…

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[JasonInDLH]

That’ll look great! Post some pics when you have them installed!

 

[mgroeger]

Is this click bait or are you really thinking of putting that tire on your Jeep with no lift KNOWING that the Rubi can barely handle a 37x12.5 tire with no lift.

 

[ohthatguy]

Is this click bait or are you really thinking of putting that tire on your Jeep with no lift KNOWING that the Rubi can barely handle a 37x12.5 tire with no lift.

My knowledge of this tire size is limited to it working well with minor tweaking on this guy’s 392 non XR . Mine is a 392XR.

38x15.5 on a Stock 392

 

[mgroeger]

The XR comes factory with 35" tires, 4.56 gears and 1.5" lift. I was unaware of the 1.5" lift until now, thought it was only tires and gears. I guess technically HEIGHT wise you could squeeze a 38" tall tire in there because of the extra 1.5" of lift. Looks like your wheels have a -24mm offset but a 15.5" tire is WIDE. I would expect to have rubbing at full cock with that setup. I don't know that trimming lugs is going to get you clear, I really doubt it. Also you really should regear to 5.13 or at least 4.88 IMO.
Since you are admittedly building a mall crawler why do you want that tire? They are going to be clunky and weird on asphalt especially with a 15.5" wide foot print. There are other tires out there at 38" tall that aren't so wide and better suited for pavement. With a 392 I wouldn't worry about the power to run a heavy tire, I would worry about the beating on your transmission over time if you don't regear.

I can't believe I am actually advising on how to build a mall crawler much less a mall crawler with a 392!!!

 

[ohthatguy]

The XR comes factory with 35" tires, 4.56 gears and 1.5" lift. I was unaware of the 1.5" lift until now, thought it was only tires and gears. I guess technically HEIGHT wise you could squeeze a 38" tall tire in there because of the extra 1.5" of lift. Looks like your wheels have a -24mm offset but a 15.5" tire is WIDE. I would expect to have rubbing at full cock with that setup. I don't know that trimming lugs is going to get you clear, I really doubt it. Also you really should regear to 5.13 or at least 4.88 IMO.
Since you are admittedly building a mall crawler why do you want that tire? They are going to be clunky and weird on asphalt especially with a 15.5" wide foot print. There are other tires out there at 38" tall that aren't so wide and better suited for pavement. With a 392 I wouldn't worry about the power to run a heavy tire, I would worry about the beating on your transmission over time if you don't regear.

I can't believe I am actually advising on how to build a mall crawler much less a mall crawler with a 392!!!

Yeah, I was actually leaning towards the 36 x 15.5 initially because the width actually is more important to me than the diameter. But I wanted to get a little more sidewall out of the situation and figured I might as well go balls out if I’m going to do it. Offsets on his wheels and the ones I ordered are -44.

The only people I’m really worried about impressing are the crossing guards that open the door for my daughter when she gets out at school every day. They used to jockey to be the ones to open the door on my BMW X6M with the bright red leather interior. If it puts a smile on their faces, I will be happy with the outcome.

 

[mgroeger]

I need to excuse myself from this conversation...

 

[ohthatguy]

I need to excuse myself from this conversation...

Ha, all good. Everybody’s got a different mission statement I guess. For me, it’s just that I want my kids to think my car is cool and they have fun riding around in it. I appreciate the feedback.

 

[azwjowner]

Experimentation is how the world advances. All we ask is that you report back how well or awful they worked for you and the pros and cons, so that others may learn about the various options available.

 

[ohthatguy]

Experimentation is how the world advances. All we ask is that you report back how well or awful they worked for you and the pros and cons, so that others may learn about the various options available.

Will do. I love putting the widest possible tires on vehicles. Normally, I am obsessed with minimizing, unsprung weight and getting the offsets perfect so that I can put every millimeter of rubber I can under the fender but this project has a very different scope.

Edit: the Geolandars were too narrow (only 12” tread on a 15.5” wide wheel?!) so I switched gears to a 20x10 -44 wheel set and Mickey Thompson 36x15.5 tires that run super wide. Here are 36x15.5s on a few vehicles courtesy of the interweb:

 

[ohthatguy]

36x15.5 tires on 20x12 wheels going on to replace the 392’s factory 315/70/17s.

i’ve only driven about 5 miles on them so far but the wheel feels great, the handling is fine and soon I will know how much they are impacting the fuel efficiency. At full lock they seem to contact the rock sliders, so I’m going to take those off and trim them up about an inch, and it should be good to go.

 

[RELBUS]

Looks good. I would bet the majority of the Jeeps I pass daily on the road are mall crawlers. Who cares. You do you.

FWIW my winch is simply a bumper ornament

 

[Dailydrivenwrangler]

I’m liking the look as well as your vision for the build

 

[ohthatguy]

Thanks, fellas. I’m genuinely shocked that the MPGs are hanging at 12.5 vs the 12.6 I was getting on the OEM 35’s (315/70/17).

Update: after getting used to the new set up and driving a little more aggressively for a couple of days, MPGs dropped to 12.3.

My next tire will be the 35x15.5 Baja Boss AT. It seems like the no compromise (MPGs, handling, acceleration, gearing change, ease of entry for the kids, stress on parts, etc.) route to super wide tires.

The stock 392XR wheel 41 lbs and 315/70/17 tire 62 lbs totals out at 103 lbs per corner. My 20x12 wheels are listed as 37 lbs and the 35x15.5 Baja Boss would be 85 lbs. for 122 lbs per corner.

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