GJeep

Commenting on every point, in that article, would be as long as the article, so I'll just say this:
That article is truth and fiction thoroughly mixed together, and some points are irrelevant to the Wrangler.

Asphalt - The fastest cars with the best traction use wide tires with LOW aspect ratio, for a good reason. Try a Vette or Ferrari with narrow tires...
Soft snow on hard surface (limited to diff' height snow), or the parallel case but with mud, are the only exceptions.

Offroad - Wider tires instantly improved my Jeeps' grip on sand, gravel, mud, smooth rock - You name it.
Then, increasing diameter added to offroad performance, but I think less than the added width did.
In the vast majority of the cases, that's exactly the opposite of what we want. We want more friction area and less force per sq.inch.
6x6 is more capable offroad than 4x4, mainly because of the added friction area and reduced weight per sq.inch.
Also, in all those times when I had half a tire width gripping and the other half in the air, a narrow tire just wouldn't work.

I suspect that those who, because of the article, seriously consider narrow tires, didn't have the opportunity to compare wide vs narrow in actual offroading - and I mean offroading, not dirtroading .

arjeeper

I suspect that the article provides a limited, but valuable look at tire width, a discussion that probably opened the minds of a number of individuals, myself included, into a handful of traction factors I'd not well considered.

I also think it's a very good contrast to what I feel is the most common factor in Jeep owners choosing tire width--that wide tires look cool.

I'm also quite confident we're not likely to see much of a dent in the wide tire trend, regardless of this article's truth or fiction!

GJeep

An article that mixes fact with fiction may mislead, because it 'sounds right', while most people don't bother to study the issue enough to be able to sort the valid facts from the rest of it.

arjeeper

Agreed. And I didn't write the article so I clearly won't support that it's 100% accurate. I can also say that after reading it, the author spent much more time in their research of the issue than basically anything else I've read on the topic.

He also makes it clear it's not a peer reviewed scientific paper.

onlyone

I can say with all the tires I've owned, wide and skinny alike the skinnys have performed much better than the wide in all aspects except on dry paved roads. There is a lot of truth to the article but as someone else said earlier it seems to be that the 80 aspect ratio works really well, no matter what the size. To each his own. I won't buy another wide tire for my JK but I will buy them for my car.

2climbbig

What is your idea of a narrow tire?

GJeep

Do I see a contradiction here?
Either the narrow tires perform much better offroad, or 80% ratio works really well regardless of size.
Isn't this a self-contradiction?
Less rotating resistance of narrow tires comes from less friction on mud, sand, etc'.
Wider tires have more rotating resistance, because they have more friction -- which is what we look for.

There's more to it - a wider tire also poses more resistance to deformation (compliance with the terrain), but then it also gives more contact area with the terrain.
Quite often, greater vertical force is not the main contributor to grip.
Imagine that the surface is made of little balls which have no friction with each another. This example is more like deep soft sand, or mud, or a dusty rock, than Asphalt is.
On those friction-less balls, increased vertical force doesn't do much to increase grab.
The vertical surfaces of the tire tread act like oars or paddles, and on a wider tire the total 'oar' area is larger.

Another factor is that on soft sand or sticky mud, for instance, the tire forms a 'wake': material is piled up in front of the tire. The tire is constantly climbing this pile.
A wider tire, which distributes the same weight over a larger area, treads more lightly and sinks less. The result is a lower wake/pile, so the constant climb is at a smaller angle -- less resistance to forward movement.

BTW, the larger contact surface combined with lower load per Sq. Inch, also make a wider tire wear slower.

dmwil

I've been impressed with the 255/80/17 KM2's on my JK. I've had them for 50k miles and lots of offroad, from the mud/dirt of the midwest, to sand dunes, to Moab. They've exceeded my expectations every time. Where I don't like them is packed snow or ice. Lack of siping has more to do with that, though, than anything else.

The biggest surprise? Sand. They have shocked me as to how well they float in deep sand. I thought they'd dig to China, but they don't. They've been outstanding in mud, rock crawling, rain, and on dry roads. They ride a little rough, but the handling and braking are excellent. They outperform the stock KM's in every way, and I've never been in a situation where a wider-tired Jeep with 33's did something I couldn't do. I'm pretty certain on rocks in Moab I was encountering less wheel spin. My buddies all felt my Jeep exhibitted significantly less wheel spin on the rocks than theirs. The damage/scuffing/gouging on the sidewalls appeared to support that.

That said, yeah, they don't look as good. Big deal. I don't wear eyeliner or have tatoos, either.

Lots of varied experiences and opinions here, so that's my 2c worth. The most important thing is that your Jeep does what you want it to do, and I'm sure most of them do.