is it worth upgrading to 35's?

N-Smooth

Smooth Gang Founding Member
Location
UT
bfg at's make great street tires and are great on dry slick rock. add moisture and you will hate life. while it was raining on the maze this last weekend even my new km2's were filling up with wet sand. i love my km2's and discount gave me just under $200 off just for asking
 

DaveB

Long Jeep Fan
Location
Holladay, Utah
With 4.56 gears the tire that would most closely match the stock set up assuming it had 3.55 gears and 28 inch tires from the factory would be: 28x4.56/3.55 = 35.9 So if you are trying to get the stock ratio/RPMs back the 35s would get you there. Mass of the tire however would affect it as mentioned before.
 

sixstringsteve

Well-Known Member
Location
UT
it's getting tougher to find a 35" tire in a 15" rim. I'm with nate, I also prefer an 8" wide wheel with 12.50s.
 
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skippy

Pretend Fabricator
Location
Tooele
I am running 8 inch wide wheels with a 15 inch wide tire and love them........Definately run an 8 inch wheel for 12.50 wide tire
 

RockChucker

Well-Known Member
Location
Highland
I once heard 8" wheels with a 12.50 or wider tire a poor man's beadlock. I would have to agree. I routinely go down to 10psi and maybe a little lower and have never lost a bead. Yet. Knock on wood.

Get the 35's and don't look back. They look better and you will love the difference on the trail. Btw I have a TJ with 4.56's 35's and a 5 speed. If I stay around 65 I return about between 17 and 18 mpg. Pretty dang close to stock.
 

Cody

Random Quote Generator
Supporting Member
Location
Gastown
What kind of trails do you hope to run? It sounds like things of the Kane Creek ilk are really the limit you intend to go, in which case I wouldn't bother with the 35's. 35's are nice, and I liked the way my last couple ZJ's worked with 35's, 4.56's, 5" lift and long arms but I wanted to be able to run trails up to the level of Pritchet. 33's vs. 35's do make a difference on a trail like that. Otherwise, with your already undersized running gear, I would err on the side of safety and run the smaller tires that are overall easier on your drivetrain. Remember, on d30's and d44's, it's not just the shaft /joint size that you have to worry about. It's the added weight and force of the larger tires being harder on ring gears, knuckles, ball joints, steering etc. Tj's and XJ's run 35's on those axles all the time, but they are also running 6 bangers and don't weigh 5500lbs loaded.

I used to put a 35 in the back. I couldn't use the factory J-bolt or the factory provisions, but it fit. I used 2 ratchet straps and it sucked it in there really well and didn't budge. The seat would fit up with low psi in the spare, but my seats were in the garage anyway since I don't like anyone well enough to have them come along...and I was usually loaded to the brim with glamping gear and fuel anyway.

I've always said, that 4.5" and 33's is the limit on a ZJ unless you're prepared to deal with a can of worms. Anything more requires a lengthy list of stuff to do correctly.
 
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N-Smooth

Smooth Gang Founding Member
Location
UT
^^^ definitely worth thinking about. driving style has a lot to do with it as well. i am rocking 33's with a 19 year old 4.0 and my d44 & d30 HATE me.

on a semi-related note, i ran kane creek for the first time this year and thought about like 1/10 of that trail was fun. never again haha
 

TRD270

Emptying Pockets Again
Supporting Member
Location
SaSaSandy
In my opinion, it isn't worth it because of the 1" extra ground clearance. HOWEVER, I do think 35's are worth it for a different reason. It's much easier for a 35" tire to roll over a bowling-ball size rock, compared to a 33" tire. Bigger tires help you maintain your momentum and roll over obstacles a lot easier. The extra 1" of ground clearance is just an extra bonus.

Just to jump in and throw a curve ball

Does this same logic apply to a 35 on say a 17inch rim? or do they have an easier time rolling over with a 15 inch rim with the larger sidewall to squish?

Not questioning your logic just more curious if anyone has better luck with same tire, same terrain with a 15in vs 17in rim and 35's

Mostly curious because we are in the same dilemma with 84 4runners' rig. The 33's are dry rotted from sitting so long and we are thinking about putting 35's on it. But she has 15inch rims and I have 17inch rims I would like to get both rigs on the same page as far as tires and wheels go. but it would be interesting to keep the 15in on hers just to see if there is a difference since everything else is virtually the same
 

Chevycrew

Well-Known Member
Location
WVC, UT
The only thing I have noticed in bigger versus smaller wheels, is when running larger tires on small wheels you get more sidewall flex (good) and hop (bad).
 

sixstringsteve

Well-Known Member
Location
UT
Does this same logic apply to a 35 on say a 17inch rim? or do they have an easier time rolling over with a 15 inch rim with the larger sidewall to squish?

Most people wouldn't notice the difference. The diameter of the tire is still 35" either way, regardless of rim size. I've heard that 17's roll over stuff better due to the sidewalls squishing less (it maintains more of a round shape when rolling), but I question just how much of a difference it makes. I've had both 35x15 and 35x17's and I prefer the 17's a little more because they have less hop. But I'd say it's really only a 10% difference between the two. The bummer is that 17" tires usually cost over $100 more each.
 

Cody

Random Quote Generator
Supporting Member
Location
Gastown
On the same note, a 35 r15 will have more bounce in a "moab bump" than a 35 r17 and will wrap itself around ledges a little better, but the 35 r17 will have less sidewall lean offcamber and while cornering at speed. I noticed a difference in both of those situations when going from 35 r15's to 35 r 17's.
 

chans

Registered User
Location
Sandy
it's getting tougher to find a 35" tire in a 15" rim. I'm with nate, I also prefer an 8" wide wheel with 12.50s.

Just curious. When you search for a 35 12.50 15 tire on Discount they show 6 and the 35 12.50 17 only show 4. Are people including the metric equivalent in a 35 for 17" rims? I know 37 12.50 15 are getting hard to find.
 
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