Blue Taco, Tire Logic.... wider vs taller?

[slowbox]

Please note anything blue taco posts means my novice butt is threading here.....

I've been prowling tacoma forums and discovering some interesting but maybe counter-intuitive bits of info regarding tire width.

In a nutshell I've got a 3" lift planned, and wanting to keep my wheels but possible new tires:

Current stock tires: 265/70/16 BFG
Yet lots of recommendations for: 255/85/16  

So less wide, but taller tire.  Folks are proposing that the narrow tires actually provide a fair bit of function over the wide depending on conditions.
Here's the thread if curious: http://www.ttora.com/forum/showthread.php?t=180050

I found it curious, I dont expect to swap out my good stock tires yet, but didn't know GATR's take on it.

-tom

[ATLSRT8]

I am no expert, but I figure for rock crawling the more contact area (wider) the better. I have seen narrow tires on mud rigs and snow rigs because it helps cut through the elements.

[DOUG]

For what we do, the more rubber on the ground, the more traction.  The wider the better. 

Sent off camber

[clark123456]

EDIT:  I understand the concern with wide vs tall for specific vehicles.

Two dissimilar things are being compared:  Width vs Height    ---  You can have a wide tire that is tall (relative to a short tire) and you can have a wide tire that is short (relative to a tall tire).  Do the same thing for a skinny tire and you should get the point.

Wider tires (relative to skinnier tires) can cause/create some issues if you are not prepared for them:
1) Front tires rubbing against parts (control arms & anti-sway bar in my case) in the wheel well is a common issue if you aren't running spacers and/or wheels with enough backspacing.  Some times you can have a problem with the rear tire rubbing also, but hopefully not due to turning.
2) Stress on steering components.  The extra contact area with the terrain surface can add significant resistance to turning which impacts steering components.
3) Splashing of water and slinging of dirt, rocks, and mud.  The extra overhang, especially if you go really wide due to the additional offset you need to avoid issue , will allow the tires to sling stuff around.
4) Stress on axle shafts.  While not likely to be a concern, the extra width can add stress to the axle shafts in turning situations, especially in situations of really sticky tires with locked axles (not axles with lockers, but axles where the locker is locked up tight (a spool)).
5) MPG hit.  More surface area equals more resistance which will theoretically impact your MPGs.  Maybe not much, but theoretically there will be an impact.

When considering your tires, think about how you will use them and what you really to get out of them (long life, look tough, Load E rating, comfort on road, etc).  Assign some sort of weighting to the various features that makes sense to you.  I like to use Excel to focus my attention when comparing things, so I would create a matrix that captures the various tires I'm considering (Y axis) and matches that to features offered by the tire (X axis) (sticky-ness, gas mileage impact, longevity/life, max weight load for towing/hauling, on-road, cost, availability after the sale, etc, etc).  Then find the tire that has the highest calculated value based on your weighting and tire feature matrix.  Then, forget everything you did and see what you can find for cheap that looks good and that you think will work for your needs



This site will let you play with the various tire and wheel sizes and compare them visually and with measurements.  http://www.rimsntires.com/specspro.jsp

[clark123456]

For what we do, the more rubber on the ground, the more traction.  The wider the better. 

Sent off camber

Doug, this guy's document doesn't agree with you:  http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html

[slowbox]

A lot to wrap my head around here, I've written 2 paragraphs and erased them all because I simply don't know.

In some practical sense I can say I need tires for moderate commuting, not dedicated trail truck rubber.

Height is a plus for clearance.  Width would seem to require more energy to pull in terms of friction, yet narrow points all torque into tighter band of space.  On a grip friendly surface, narrow would carry, right?.  In mud/snow surface I presume width is king.

***grain of salt pls... I'm just kind of tossing out some thots.  I'm a spacial thinker (and i hate it) rather than a good numbers man.
   

[DOUG]

No Clark I don't agree with him lol.  Physics don't lie.  The larger the contact area of a like material, the more the friction, and therefore traction in the case of a tire.  The wider the same height tire, the larger the contact patch.

Plus you can't wrap around a rock without width.  

Plus anything that says expedition is all about gravel roads and camping...

But I'm no Einstein

But I did stay in a Hilton last night

Sent off camber

[Danny Kinder]

If you are going 33 tall it seems that the 10" width would be a little unproportional for what we do, although this is not an uncommon size + you can run bfg's.
Have you thought about 285/75 R16 (33x11.5) you will have a few more options.

It is good to get opinions and ask questions like you are doing!


TAPATALK

[jgerhard]

Another thing you need to look at is the side ply.  It's easy to cut a tire off-road on the sidewall.  You want a thick sidewall or one of the brands that uses Kevlar to keep things light.

[clark123456]

No Clark I don't agree with him lol.  

Ah, that perspective thing!  


The one thing in the article that caught my attention was about load distribution of 'vertical load' (i approached the article with skepticism).  It made sense to me on paper, but I can't attest to real world application.  My limitation with my 33x10.50x15s always appeared to be height versus width (ground clearance killed me).  If I had to make a decision between width and height, such as being confined with a certain wheel well size and lift, then I would choose height based on my previous experience with those 10.50 tires I mentioned.  Those skinny tires are BFG KM2s, so they grip like a mofo, but so did my shock mounts, control arm mounts, pumpkins, and skid plates.  From an appearance perspective, my 35x13.50x15s look MUCH better/tougher than those pizza cutters I have.  

I ran the 10.50s on the Bell FS trail ride and made it up the v-ditch with no issue (locked F&R), but I'll be running the 35s at Morris.

[DOUG]

He says he is writing to substantiate his belief

Sent off camber

[PopTop]

Once you get to 33" tires in BFG's I think they're all the same width up to 37" so there isn't much choice to begin with.  To the original question, 265/70/16 or 255/85/16. The isn't much difference, so choose the one you think will suit you best based on your personal preferences (height, looks, etc.).