Wide VS Narrow Tires & Wheels -- Air Down Contact Patch Size Test

Always good tire comparison videos by these guys.

Saw this when they posted it a few days ago.

Great video.

I watched that and I still think there's something missing. Sure the tire prints are neat but it doesn't take into account either moving or lateral stability. Sure the skinning tire might be fine on a pool table but put it on unstable ground and let's see what actually happens.

Here I am on skinny 11" tires:



Here I am on 13.5" tires:



And again on 13.5" tires:

Interesting video. As complicated as it is, I still think there's more to it than shown. Overall, I think I prefer Tinkerers Video, though even simpler I think he gets less into the weeds and overall understands the physics better. The bit where he got into calculating the tread area is interesting but only partly relevant imo. Soft soil reaches between the lugs anyway, and on hard surfaces like rock you are more interested in the shape and size of the overal contact patch than the pressure of it.

One thing missing from both videos, and an undeniable advantage of wide tires over skinny, is ultra low pressures. Think low single digits for snow wheeling.

In either video, its demonstrated that despite width, the contact patch area is the same for the same pressure, but it is a different shape. Tinkerer did a great job demonstrating the qualitative properties of that shape with regards to longitudinal grip. But running a skinnier tire means you use up sidewall deflection faster as you deflate.

If airing down both a skinny and wide tire, eventually the skinny tire will be effectively flat (on the rim) while the wide tire is not. This is evident in snow rigs and modern tractors. Wider tire allows you to run a lower pressure all else equal.

That said, most of us aren't wheeling at >5psi so the other qualitative tradeoffs are more important. Overall, i'm a fan of the look of a pizza cutter anyway

With my experience I prefer a skinny tire for snow packed roads. I've driven both. But then that was before the internet. Neither tire watched a youtube video to learn how they were "supposed" to behave.

I found it easier to stay on the road with a skinny tire, kept slipping off with a wider tire. Didn't use chains.

I have both skinny and wide setups: 255/80R17 Falken Wildpeak AT3s and 315/70R17 Bridgestone Dueler AT3 REVO and use both year round in Alaska, including winters. There is not much of a noticeable difference, in 1'+ deep snow on/off-road or on ice covered roads, with maybe a slight edge in on-road grip to the Wildpeak skinnies. Whether that's due to the width, different vehicle manners or the tread/tire/compound/pressure, who can say.

Skinny vs Wide is the "which is better? 9MM vs 45?" debate of the 4x4 world.

Truth is, the best caliber the one you train with.

Similar for tires. The tire whose capabilities, limits and grip threshold you're familiar with in all terrain types will be more advantageous to you as a driver, than whatever infinitesimal % of improvement might exist between those same or similar sets of tires between wide and skinny.

Grip compound, tread pattern and design, siping, wear rate, road manners are all more important than width anyway.

I always go stock or 1-2 up sizes mostly for looks on all cars ever conscious of weight and geometry.

With literally 1000a of miles back country 4 season off road driving (oil industry - exploration stage on fresh cut lines and no road terrain) and off road bush motorcycling this practice in these conditions have never let me down.

Unsprung weight is worst enemy of at any speed and do these bigger tires ever weigh a lot not to mention wheels.

I was shocked at how light the Michelin LTX trails are.....just don't take them into off road conditions or sidewall will rear out instantly.

Hug tires look amazing though.

All depends on end use I already have 2 complete sets of wheels and tires and need a 3rd ...could probably use one more addition set. Yes I like shoes too haha.

I don't have a ton of experience with AT/MT tires, but I can say my 38x11.5 definitely slip/dig more than my 35x12.5 did. Not so much that I've got hung up or stuck (the additional height helps a lot) like @Bikeric shows in his videos, but yeah, pretty much exactly that.

Through my own trial and error, I've come to prefer narrow tires for my use. Have no idea how close the video is to my particular use as I didn't watch it. I'm sure other people have learned a wider tire is better for their use.

Use what works best for you.

One of the best videos on this subject. Thanks for taking the time to do it right.

I think another factor is the load range. I always use a C range tire because the sidewall is more flexible. Therefor I am going to guess that the tire patch is a little larger. Neither video covers load range. However most large rock crawling tires are only available in C range, which, in my opinion, validates my guess.

jzweedyk said:

I think another factor is the load range. I always use a C range tire because the sidewall is more flexible. Therefor I am going to guess that the tire patch is a little larger. Neither video covers load range. However most large rock crawling tires are only available in C range, which, in my opinion, validates my guess.

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That makes sense for that use. I'm usually on old logging roads and one of my biggest concerns, especially when aired down, is cutting the sidewalls. I'd much rather have D or E tires for hopefully thicker/stronger sidewalls.

kodiakisland said:

That makes sense for that use. I'm usually on old logging roads and one of my biggest concerns, especially when aired down, is cutting the sidewalls. I'd much rather have D or E tires for hopefully thicker/stronger sidewalls.

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For cutting I would agree that a D or E tire would be better. But for puncturing not so much. One of the reasons I air down is for puncture resistance. Think of a balloon. If it does not have too much air in it and you try to prick it with a pin, it simply deflects. If it is really full of air it will puncture. Also a C range tire will deflect more at any pressure, so it will be less likely to puncture. I often go over sharp rocks with no punctures. Also the video makes reference to Method Bead Grip wheels. I run them on my Bronco and are sold on them.

jzweedyk said:

For cutting I would agree that a D or E tire would be better. But for puncturing not so much. One of the reasons I air down is for puncture resistance. Think of a balloon. If it does not have too much air in it and you try to prick it with a pin, it simply deflects. If it is really full of air it will puncture. Also a C range tire will deflect more at any pressure, so it will be less likely to puncture. I often go over sharp rocks with no punctures. Also the video makes reference to Method Bead Grip wheels. I run them on my Bronco and are sold on them.

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They said aired down with the D or E. Which you can, you just have to go a bit lower to get the similar effect. D and E sidewalls will still deflect. And the stronger sidewall will definitely help with side punctures. Just more material to go through.

That being said the tradeoff is weight. When I got my K03s the only option was the heavier rated ones but I will probably go with a lighter rating when I wear these out.