Questions on Narrower Tires for On-Road Performance

I've been lurking around the tires threads a lot recently as I'm trying to figure out what tires will be my next. I've done my best with searching, but I have seen a lot of very general posts, e.g., KO2s SUCK, KO2s FTW with little regard to terrain type (on- or off-road) or tire size (balloons on wet pavement I imagine are never going to be great).

Here's what I know about myself:

• I hereby acknowledge that I dig the aesthetics of certain tires and recognize that it shouldn't come into play but it will.
• I live in Seattle where roads are wet.
• Truck is a grocery getter and a weekend adventurer
• The weekend adventures are not off-roading in the truck but off-roading on bikes or on foot.
• If I had cared about MPG I would have gotten a Forester.

Here's what I don't know about my next tires:

• All else equal, will a narrower tire perform better on wet pavement?
• How much can a slightly narrower tire help offset the dry- and wet-pavement performance loss of an AT tire?
• At what diameter-to-width aspect ratio does stability become an issue?
• What do 245/75R17s look like on a truck, anyway? Pictures please!

Basically, I want to run a good looking AT tire but I like the skinny look and realize I am kidding myself if I consider off-road capabilities to be more than a nice-to-have in my decision making process. Your honest and backed-up opinion is much appreciated here. I am looking to learn as much as I am looking for the dope-assest set of new tires.

 

Narrow tires provide greater pounds per square inch of contact to surfaces on the ground. This is why narrow tires are recommended on slick/icy surfaces. Narrow tires, due to their smaller contact patch, generally provide less friction and thereby offer better fuel economy.

Wider tires are good for softer surfaces such as sand and deep snow. Wider tires are also generally preferred on racing vehicles to provide more lateral support for cornering, larger contact patches for acceleration, etc.

For off-road purposes Tall/Skinny is "generally" better due to that greater pressure over the contact patch. However, wider is better for those sandy or snowy off-road conditions.

For reference: 245 tire width is what came on SR, SR5 versions of the 2nd Gen Tacoma.

Example:


This is what 265 width looks like:

This is what 255 looks like (on a 33" off-road tire):

 

I live 33 years in the Northwest and 26 years in Arizona, and I have 4 wheeled all over the continent. That is the basis for my observations about tires. The questions you asked are good ones, but the answers are more complicated than you proposed. I'll give you my bottom line first, and then if you are interested you can read why I think this.

Bottom line: Skinny performs better in every situation, on and offroad, except soft sand. I have experimented with 225s, 235s, and 255s on the Tacoma, all on stock 16x7 wheels. On a dedicated arctic truck, extreme wide tires are better in deep powder, but that has no bearing on a street driven rig. You can compensate the loss of track width with 1" or 1.25" wheel spacers. The added width gives the truck a really nice look too! Go up at least one load rating for skinny tires to prevent tire roll on corners. My favorite is load range E. My best set-up for a primarily street driven rig is 235/85-16, LR-E on a 7" wheel with 1" spacers (31" tall). For a truck that gets heavily used offroad, 255/85-16 LR-E on a 7" wheel with 1" spacers.

In deep muck, the narrow tires push less ahead of them and create less resistance. When you air them down, the contact patch they create is longer than it is wide. On a wide tire you get a mostly square contact patch aired down. The result is that you have much more directional stability with a narrow tire in soft slick stuff. I spent a summer in the Wyoming wilderness at about 6,800 feet, and got to test this very well. After severe rains, the bentonite rich clay was like driving on deep grease. The 4 wheelers from Casper would come up and try their luck getting up my road. I put my tacoma with 235s aired down to 18psi up against big trucks running 40"+ monster mud tires. Every time they tried to power ahead, they lost control. My truck was able to maintain direction, even under power. I was essentially running on mini tracks. The end result was that I got way farther down the road than any of them. I was only stopped by a long steep muddy hill. In fact, The biggest problem I had was caused by the ruts the bigger trucks created. Once I got past the mess they created, I was cruising. The only vehicles that got farther without going off the road or getting stuck were ATVs. It took 18 dollars worth of quarters to wash the mud off my truck! The same things happen in snow and ice.

I've driven extensively on ice and snow with them too with great results, even pulling a trailer. I had mine siped by Les Schwab. The narrow tires channel water out faster and resist hydroplaning. In deep snow you will never float on any Tacoma street sized tire. Forget that logic unless you are building an arctic rig. The better tack is to get concentrated contact pressure by using a narrow tire. What stops most trucks with reasonable width tires in snow is not traction really. It is plowing, both ahead of the tire, and by frame dragging. Once you start plowing snow with your frame/suspension, you probably won't be going much farther unless you have chains. Skinny tires run chains better too! The 255s give you a bit more clearance.

In my experience, deep sand is the one place that wider tires seem to work better for me. Sand is just a weird thing all by itself. The wider tires give you a little more resistance to dig out. I still don't run them in AZ. If I wanted the advantage, I would just buy another set of weekend tires and wheels for playing in sand.

On road, the narrow tires track better, require less caster, and are not pulled as much by ruts in the road. They are also lighter for improved braking, acceleration, and reduced suspension, drivetrain, steering, and bearing fatigue. I got 132K out of my factory brakes, and my wheel bearings and clutch are still good after 146K. The E rating makes the tires a bit stiffer, so that you get very little sidewall roll. 34 to 36 PSI works best on my truck, weighing 5600 pounds, split 52/48%. Chalk your tires to find the best pressure for your rig. Many people badmouth E rated tires because they over inflate the hell out of them. An E rated tire requires no more pressure than a C rated tire for the same weight of truck. In fact, they may require a pound or two LESS. I routinely get 45,000 miles out of my tires on the Tacoma. I'll be buying my 4th set in about a month (255/85-16 Cooper SST Maxx). I love Cooper tires.

Anyway, these are my experiences. I'll admit that wide tires look good, but any more when I see those tires on a truck, I don't think "cool", I think "fool".

 

Backing up the above info:

http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html