3 Scientific Experiments to Settle This | Wide vs Narrow Off-Road Tires

Awesome video Kai! Very informational! Glad to be working with you on this!

In the mud tall skinny super swampers rule

Everyone knows pizza cutters are better. This is a cool video

You Sir have way too much free time

any one has any points for soft dry sand ?????

Narrow tires do better in snow experience taught me

Good video but as a Canadian you didn't test in snow,rain or mud. Problem with engineering is every thing looks good on paper. Practical trials give accurate data. My xj has 14 inch wide 33s on 15 inch rims. Rims size has alot to do with tire deformation and stoping on ice is very noticeable.

You forgot to test the treat compound

Pizza cutters won't work in deep mud as well. Some people who off road, Drive on mud tracks with hill climbs and bounty holes. So they dont worry about rock climbing 😅

I’m curious about your thought on General Grabbers.

Narrow is good in snow wide good in mud

Love the video but I feel like the tire flex also has somewhat to do with the wheel width to tire width ratio

I would be interested in see the Patagonia Mt02 ,

Contact patch is a function of tire pressure and vehicle weight. Same weight and same pressure will lead to similar contact patch size.

Tire flex ramps. Under increasing load (constant weight, lowering pressure) the flex remains relatively flat until a critical point where the flex starts to increase greatly. Narrower tires reach this critical point at lighter loading (higher pressure).

What is happening at this critical point is the transfer of force on the tire side wall, instead of the contained air pressure. When skinny and wide tires are at full pressure, neither had a contact patch that reached tire width. The entire load was supported by contained air; the sidewalls are only containing the air pressure. As the contact patch width approaches the tire width, more load is placed on sidewall directly. This works from the other direction too; as tire pressure decreases, the contained air needs a greater tire area to support the same weight, thus the tire must deform more. Either way, as contact patch width approaches tire width, tire flex increases.

Thus the narrow tire contact patch approached tire width at higher pressures, loading the sidewalls for deformation, earlier, resulting in narrow tires having greater flex at same tire pressure and vehicle weight.

The choice between wide and narrow tires is if you want less or more flex at the same contact patch.

Excellent video!

Edit: terrain still matters for tire width choice. Contact patch is a reaction from a driving surface that can support the same pressure. On soft terrain that cannot support the pressure, the terrain will deform around the tire. Thus tire geometry/dimensions matter, as the terrain is forming the contact patch around the tire. Narrower tires let you sink through the soft terrain and wider tires let you float above it. For snow you want the skinniest tires to sink through snow and reach the pavement underneath for a normal contact patch. I know for sand and riverbeds, you want a sweet spot to sink in about 3 inches. Too wide, you are stuck floating on the loose top layer with no grip. Too narrow and you end up digging with too much material in front of your tires.

Useful content. Thank you!

When you used to buy tires in inches they would lie about width.
A 12,5”wide tire would measure 10 wide tread.
A 10” wide tire would measure 8”wide tread.
15”wide tire would Measure 12.5”wide tread.
Dry rock crawling in Moab with a 9”wide tires 295 was a big grip reduction. In my bone stock, 100 series. I only upgraded the tires, BFG KO2

Super video. So many possible variables, sand,and mud, thick or loose, rolling resistance, road noise, unsprung weight of narrow vs wide. Vehicle track width difference wide vs narrow.

Now I'm wondering how this would work with mountain bike tires

Lose any air and you run risk of rim pinch. Like diff between a ten speed and a mountain bike. I like a wider to protect rims and get the floatation . Skinny is great in shallow mud and snow . But when the going gets tough bigger is better. The skinnier you go the more likely of failure . Get a slow leak or seep out on a rock and the bigger one will resist seepage and stay on the bead way more. Rolling resistance , fuel milage and price are a downside of bigger . But thanks for getting all technical for us to visualize it.

I have zero rock crawling experience, but I've seen tall skinny tires do things in the mud that blew my mind. I love having the scientific data to back up my anecdotal evidence! Awesome job!

One thing about wider tyres vs narrower is on the same rim you can lower the wider tyres pressure a lot lower without risk of de-beading. The narrow tyre sidewall doesn’t bulge out as much as it is not much wider than the rim width.
I noticed this when I went from a 9” wide rim to a 8” wide. Of course this doesn’t matter if your rims are bead locked but bead locked wheels aren’t street legal in Australia

I don't find this very surprising. Basically, pressure is nothing but the weight-force that the contact patch supports divided by the area of the patch, so if you compare same pressure then obviously the patch will have the same size regardless of tyre model. (Until you get to extremely low pressures, where sidewall rigidity distorts the picture.)
But that's kind of missing the point, because same-for-same pressure doesn't make a lot of sense to compare! As every cyclist knows, different-width tyres have very different pressures at which they work best: a road tyre is operated at 50 psi or more, a mountainbike tyre at around 25 psi, and a fatbike tyre at 10 psi or even lower. Of course you can vary the pressure in all of them, but running a narrow tyre at too low pressure risks damage (pinch flats) and running a wide tyre at too high pressure prevents it from giving its full offroad performance.
For cars the same should apply too: wider tyres only pay off if you run them at lower pressure (or on a heavier car), else they just add mass and rolling resistance without benefits.

And if you don't want to are down just get a skinny tire and then you don't have to worry about airing down you got more weight on a smaller patch which gives you more traction to begin with anyways so you're good I never are down

I don't even need to watch the video but nobody should have to question what tire they need if you want better traction off road or for slippery weather get skinny tires if you want traction on the road in normal conditions get fatter tired

I like wider tires on my truck that has power steering, but on my old Power Wagon with no power steering I use narrower tires and it’s easier to turn…

Narrow tyres perform better on muddy terrain. I'll continue watching if my sentiment is supported by this video. Thanks for this video.

Tires with sharp edges are far better than rounded edge tires.

Good year used to maka 10 ply work horse tire which was unbeatable in traction .But of course they no longer produce them.

Take this from a New England resident for 55 years. Narrow tires do not plow or toboggan in snow. Wide tires are terrible in snow.

Excellent info , thank you. I am interested in the rolling resistance of these types of tires and how it affects gas mileage. My experience has shown me that a wider tire will give better floatation on soft surfaces but does not work as well as a narrower tire on slick hard surfaces. The downward force on the contact patch is a very important factor. Function over form gets the job done.

Real world driving conditions, stoping, accelerating and cornering, added weight with passengers, etc I would think the wider tire has better contact.

Now, do a comparison of the km3 in heavy clay mud skinny vs wide. I've heard skinnys can help with hard bottom mud pits, but wides are needed for the bottomless pits to work more like flotation tires.

Also, I'd love to see how the cooper stt pros handle compared to km3 on rock.

In winter driving narrow tires are much better than wides ones. I remember a friend who bought big wide tires for is CJ5 and was not able to drive at the first snow and had to buy narrower tires for the winter. In my opinion wider tires only advantage is for floating a bit better in deep mud and not being stuck on the differentials. I all the time use winter tires narrower than my summer tires. They cost less and are much more efficient. Now the cars have too wides tires for the weight of the vehicules and they float on water and are dangerous. They are only marginaly better on dry conditions.

Vielen Dank für die wirklich sehr aufschlussreiche Einsicht.
Ich hatte mir schon sowas gedacht. Aber das schmale Reifen so viel besser sind, hätte ich nicht gedacht! Wow!
Mach weiter so, sehr interessant.
Beste Grüße aus Deutschland

Just upgrade your vehicle from a Toyota to a Jeep you will have more fun and you can customize your Jeep in any shape or form of anything roadworthy and off-road Worthy

Hello there,

Your video is informative in tires size. I am doing my research as well when for my tires on my 2010 tundra double cab 2x4. The tires on my 2010 right now are 285/55R18 enough more to turn left and right so I am good there. I am looking to do a 4.2 lift kit by Readylift with fox shocks . I call many shop that specialize in lift kits and ask a question about tire size and said I can going up to 35.35 are to wide and I will have no room to turn.then I was thinking what size equal to my 285/55R18 there are 33x12.5x18 . So the question I need to know with your knowledge on tires size , will these tires size with rubbing and cutting? Please advise on the 33s or what tires will fit with the 4.2 readylift with out rubbing or cutting.
Thank you in advance sincerely Freddy.

Hell , the U.S. army knew this in the late 30's

I’m more interested in track performance (sidewall, tire diameter, tire width) but this is still very fascinating.

Are you running wheel spacers with the 255's? or do you not recommend to run spacers?

I didn't find that shocking. People put too much emphasis on looks and fashion over performance and function. I roll pizza cutters on my toy and it kicks ass off road not to mention the dynamics on road come into play with the extra wind drag and road resistance of the wide tire 🤔 ...but they don't look kewl 😭 lmao

The tire sizes Im seeing are either too wide or too tall for my car, so Im really not sure what to do or choose.
Im looking at getting a set of 33s or a 34 on my 4th Gen 4Runner. Upgrading from my stock 30s.
I already have it lifted and willing to do some mods. I don't do anything hardcore offroad as its my daily driver.
Narrower for me looks nicer and better for my Alberta winters

I like the Baja Boss ATs, but they only come in a 285/70-17, or a 295/70-17.
295s - (33.7" Tall, 12.1" Wide) - Taller, which is more of what Im looking for, but they are wider.
285s - (33" Tall, 11.5" Wide) - Still a decent hight, but maybe a bit smaller than what Id want, but they are narrower.
These are my options as I don't want to get a set of 35s.

My other option is to get my backup tire option, the Toyo Open Country AT3s.
Here they have a 255/80-17, or the 285/75-17.
255s - (33.1" Tall, 10" Wide)
285s - (33.9" Tall, 11.3" Wide)

In what situations would a wider tire be better? How skinny can you go until you start seeing adverse effects?

The day they put tall skinnies on tanks is the day I put them on my truck.

I think you're supposed to break them in to your vehicle

I was able to get 33’s on my 1st gen without mods by buying a narrow tire. Acceleration, fuel mileage, and steering response is noticeably better. I had a wider 30’s on before and the 33’s that are narrower are better. Tire weight makes a huge difference on many many components and things and would make an interesting experiment to see whether the benefits out weigh the costs to ball joints, fuel economy, or the mods required to fit the fatter heavier tire. Me personally, I’m staying with the narrow tires, ground clearance matters.

I don't know how I ended up watching your video, but I liked it! Having grown up in Southern Vermont, where our fifth season is mud after snow, we were taught that narrow'eeeerrrr works better in both scenarios. 🤷‍♀✌

I have been preaching this for 35 years 👌

Word.

From my experience in road racing I have to ask, when your measuring the contact patches initially are the tires “worn in”?

I ask because the reason we don’t race on brand new tires is to wear the contact patch in for them. This varies for the weight of the vehicle, corner of the vehicle they are on, chamber, etc.

I was always told a new tire had more of a circular patch and never really believed that until I saw this video.

While this is great confirmation for me it kind of nullifies your testing (assuming your tires aren’t worn in).