Reflecting on Changing Tire Size over the years..

[LRNAD90]

So I'm probably dating myself here, but I remember back when I was younger, and first got into trucks and off road driving, the 33" tire was considered a large tire. Larger tires existed, but it seemed rare to see anything larger than 33's on the trail, even on serious rigs, particularly on smaller trucks. 35's were around, but mostly on larger, full size trucks.

I remember when I got my '89 Nissan Pathfinder, and people thought the stock 31" General Grabbers were absolutely massive tires (for comparison sake, an '89 a Jeep Cherokee came on 225/70-15's (27.5") and an '89 Wrangler came on 225/75-15's (28")). The 4 runner was the only other similar size SUV at the time (that I recall) that offered a 31" tire.

Most ROW Defenders came on 235/85-16s (32ish")
The NAS Defender came on 265/75-16s (32ish").
Discoveries arrived on 235/70-16s (29ish") rubber..

At one point I thought the Defender seemed 'just right' on 33's, now they seem kind of pedestrian..

Now you can buy Jeeps and Broncos off the showroom floor with 35" Tires..
37's don't even look overly large on current Jeeps or Broncos, and seem like the 'new' 35" tire..
Hell, I see a lot of Jeeps on 40's now..

Likewise, locking differentials were highly specialized items (or at least it seemed like it to me at the time) back then. Today many trucks can be had with lockers, many even front and rear.

Makes it seem like a mildly modified Defender isn't even competitive (capability wise) with current stock offerings..

No, I don't really know where I'm going with this, just reflecting I guess..

Feel free to add your thoughts..

 

[pmatusov]

The "real" trails set things right.
We've seen our first JKUR on 37s with a broken driveshaft about 1000 feet into the Rubicon from Loon Lake. We've also seen a ZJ on 40s - but running a front Dana 60 and rear Dana 70, so the owner's ground clearance is what it would have been with Dana 44s with 35"s.
And you keep seeing people on old CJ5s and FJ40s on 30-31" tires with open diffs all over Colorado trails.

At least, the off-road candidate trucks still have sensible rim diameters.

 

[erover82]

Vehicles keep getting larger, and proportionally the tires have as well. There's also an arms race aspect to it fueled by the inherent bravado and competition in pop off-road culture. The increasing tires sizes relative to body size are chasing after a smaller and small percentage of trails that actually need them.

The stats for a typical short wheelbase 4x4 could look roughly like this:
28" tires - 70% of trails
30" tires - 85% of trails
32" tires - 95% of trails
33" tires - 99% of trails
35" tires - 99.5% of trails
37" tires - 99.8% of trails
40" tires - 99.999% of trails

Diminishing returns, not to mention exponential costs.

I find it grounding to consider that I can get to anywhere I want to go with 32s and a winch. I'm not really interested in the artificial challenges I could attempt if only I had 37s and spent $$$ on supporting upgrades.

The solution to vertical climbs with zero traction was solved decades ago, and it didn't involve monster truck tires.

 

[blueboy]

I find it grounding to consider that I can get to anywhere I want to go with 32s and a winch.

Agreed. Always have considered a winch as an additional traction aid albeit the last resort. Camel Trophy Rovers ran tall / skinny and did pretty well with winches grinding.
On tire size pretty sure owner age is also a factor. 😁

 

[erover82]

Agreed. Always have considered a winch as an additional traction aid albeit the last resort. Camel Trophy Rovers ran tall / skinny and did pretty well with winches grinding.
On tire size pretty sure owner age is also a factor. 😁

Yeah it's unfortunately often viewed as a failure, when in reality it's a success in preparedness. Additionally, the use of traction boards, stacking rocks, winching, etc is one of the more strategic and invigorating parts of 4wd travel. It breaks the boundary between glass and environment. That's why, regarding CT, those guys were longing for it after being confined in the cab for long stretches of humdrum hard pack.

 

[pmatusov]

The stats for a typical short wheelbase 4x4 could look roughly like this:
28" tires - 70% of trails
30" tires - 85% of trails
32" tires - 95% of trails
33" tires - 99% of trails
35" tires - 99.5% of trails
37" tires - 99.8% of trails
40" tires - 99.999% of trails

This is a good use case breakdown, but it doesn't account for "which trails."
My WAG is that people going over 35" (this number is also subjective) are from two classes - poseurs who never leave pavement, and people "tuning" their vehicles to their very local trails or mudholes.
Locals living near Johnson Valley in California or Rubicon or Fordyce Creek or Dusy Ershim are likely to sport tall tires, but for them these places are in the "weekend bash," rather than "once or twice in a lifetime" category.

 

[evilfij]

Keep in mind traction control was largely unknown (came in 93 rear only on Range Rover) and then DII and I can’t recall when on defender, maybe TD5 era. It really helps in my experience for soft roading as I am most likely to do.