Expensive tire sidewall cracks; slow leak

Maintenance/Repairs
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The larger the wheel, the more advantage alloys have in terms of weight. I’m not curious enough to spend the time to find an exact sized comparison wheel in either material. Generally, it appears as though the alloy has the advantage even in a 14" diameter wheel. However, the materials and engineering did not exist back when that car was made so the point is kind of moot.

Regarding the propensity for modern wheels to be larger, that is likely to be originated by marketing. People seem to like a larger wheel size over a smaller one. So marketing goes to engineering- if we want to sell in the current market, wheel size needs to increase. OK, that means a heavier wheel so what do we need to do to compensate? We can change the gearing in the drivetrain to better match the larger diameter wheel and we can adjust the engine power band as well… the point is, the entire drivetrain of the vehicle is a system. Tradeoffs can be made to accommodate less than ideal scenarios in any of the components…

205

This may interest no one. But regarding the failure of Wilderness AT and ATX tires on Ford Explorers, Firestone apparently commissioned a technical study
http://faculty.ce.berkeley.edu/sanjay/REPORT_WEB_Secure.PDF

It is hard to understand for those of us that aren’t engineers. :frowning:

But it focuses a lot on tire belt temperature, tire inflation pressure, and load.

But it is interesting to note that the study claimed that for highway speeds, low inflation temperatures, and heavy loads, “belt edge temperatures” could be 50 deg C over air temperature.

Also, tire problems were correlated with climate - hotter climates lead to more tire problems.

And the lubricants used at a particular factory were also argued to be associated with more tire problems. According to

that factory was closed.

That Wikipedia article has more info on the failures and the consequences.

BTW, AFAIK, my Wilderness AT tires (that came with my 1994 Ford Ranger - if I remember right the Ranger was made in October or November 994 and I bought it new in early 1995) experienced no problems other than punctures, and worked quite well for me. But I took advantage of one of the recalls (probably the one from May 2001) - simply because they were old and worn enough that free new tires seemed like a good deal, though I would otherwise have kept them for a while longer. If that’s right, they lasted over 6 years, and could have lasted somewhat longer. I was very well pleased with them. But they were on a Ranger, which had lower weight load and possibly a lower center of gravity than the Explorers, and specified a higher tire pressure. Firestone had claimed that the Explorer’s high weight load, high center of gravity and low placard tire pressure caused the problems.

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Ah … Mmmmmm … Not exactly

First, your link to the technical paper doesn’t work. I suspect you are referring to this: Barry’s Tire Tech: Dr. Sanjay Govindjee’s Report

As a tire engineer, I studied this whole affair very carefully - both as an employee of a major tire manufacturer and as a failure analyst.

I go into more detail here: [Barry’s Tire Tech: The Ford/Firestone Controversy](Barry's Tire Tech

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207

This is really old news and does not relate to your current need for tires. Plus the 1994 Ranger does not compare to the Ford Explorer problems .

Also you don’t seem to understand the difference of the Ford Ranger 4 wheel drive and your All wheel drive system you now have.

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CapriRacer): BTW, your link above to the report doesn’t work either. Maybe they have made it hard to link to. But your link at your web pages does.

I love your web page. And I love the Tire Rack review site. Finally, sources of good comparisons between multiple brands & models.

Can I rely on the Tire Rack touring tire & grand touring tire test results to be reasonably accurate for the Venza, with its 245/55R19 tires? That obviously a higher wheel and sidewall height, which differs from the vehicles Tire Rack tested these classes of tires are are tested on.

The bad experiences I’ve had with flats in remote areas has convinced me I want puncture resistant tires, because the places I drive must have more nails and bolts than most - but I’m not sure how to find that. Do you know how?

VOLVO-V70: It is true I don’t fully understand the differences between what are now called AWD and what are now called 4WD. Auto dealers told me the two names are now interchangeable. E.g., both can be manually or automatically engaged. Was that wrong?

In any event, I already have my vehicle, and it is in no danger of failing soon, which in turn means I’ve chosen my transmission, wheel size, tire size and pressure. If the tire dealer says the tires need to be replaced, tires are the main factor that can change.

Oops, my link to the report started working again. And so did yours. Maybe something about the website.

209

You said you have a tire shop you trust so let them guide you and stop making this difficult. I have even had store brand tires that gave good service.

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210

I’ve never had them but I believe puncture resistant tires just mean you can drive 50 miles and replace the tire.

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211

Simple, AWD:

  • Torque Distribution:

AWD systems constantly monitor wheel speed and traction to determine the optimal torque distribution to each wheel.

  • Center Differential:

A center differential (or equivalent) allows the front and rear axles to rotate at different speeds, which is crucial for smooth cornering and preventing binding in AWD systems.

  • Slippage Detection:

Sensors detect when a wheel loses traction (e.g., on ice or snow) and redirect power to the wheels with better grip.

  • Full-time vs. Part-time:

Some systems, like Subaru’s, are full-time AWD, meaning they constantly distribute power to all four wheels. Part-time AWD systems may primarily operate in front-wheel drive or rear-wheel drive mode and only engage the other axle when needed.

  • Electronic Control:

Modern AWD systems often use electronic controls and clutches to manage torque distribution, allowing for quick and precise adjustments based on driving conditions and driver input.

Traditional Four Wheel Drive does not have a center differential.
Key Characteristics of Traditional 4WD:

  • Transfer Case:

A key component that allows the driver to select between two-wheel drive (typically rear-wheel drive for trucks) and four-wheel drive (4H for normal conditions, 4L for low-speed, high-torque situations).

  • High and Low Range Gearing:

The transfer case often offers a low range option, providing increased torque at lower speeds for better off-road performance.

  • Driver-Selectable Modes:

Drivers can typically choose when to engage 4WD, unlike some AWD systems which are always active.

  • Locking Differentials:

Some 4WD systems offer locking differentials, which force both wheels on an axle to turn at the same speed, providing maximum traction in challenging conditions like deep mud or snow.

  • Suitable for Off-Road:

4WD systems are designed for rough terrain, offering enhanced grip and control when navigating obstacles.

Using 4WD on dry pavement can cause drivetrain binding and potential damage, as the front and rear wheels need to rotate at different speeds during turns.

Try driving a 4X4 on pavement with 4WD engaged, you will soon learn the difference.

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212

Another vote in favor of the tpms. Sitting in the drive through, my monitor went off. Down to 21#. Didn’t have to look very hard for the big ole screw to be seen. Right on the edge of the tread so the tire is ruined. So off to Goodyear in the morning to see about four new ones. Just a couple days ago I checked and had 11/32 nds so started to think about maybe replacing before winter.

213

11/32”?

You seem to buy new tires every winter.

214

Checked it again, almost 8//32. So you recommend buying just one new tire on fwd? Then what? Buy three later on? Constant mismatch.

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You should buy 4 tires, someone else will use the 3 good tires you discard.

8/32” is good tread, many new tires come with 9/32” tread. Michelin Premier All Season tires have 8.5/32” when new.

216

They are five years old. They don’t sell used tires. They’ll go to the dump.

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Most (or all) of the company’s in my area (at least 30 I have delt with) go through the used tires and sell the “good” ones to used tire dealers before being properly discarded, or the company’s picking up the scrap (take offs) tires also own used tire shops and go through them picking out the “good” ones before being properly discarded…

Besides, I think there are laws about dumping used tires in landfills, I know TN has them…

218

That’s what they told me last time I was replacing serviceable tires. They charge about $4 each for the recycling fee but no idea what the recycling folk# do with them after that.

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My old Ranger had a transfer case, with very low gear for 4WD mode, and I believe the center differential always locked in 4WD mode, though it’s been a long while since I had it, so that might be wrong. I was warned not to drive at highway speeds in 4WD mode on on pavement, unless it was covered in snow or ice, because it might literally flip. And, supposedly, even driving at lower speeds on pavement could damage the transmission. So it met your definition of 4WD. But that was a long time ago.

The modern Ford Explorers with “intelligent 4WD” don’t apparently match your description - because, at least according to one dealer, they can separately control all 4 wheels. They sound somewhat more like AWD.

I think that is true of a lot of modern “4WD” vehicles. E.g., the Honda Element 4WD models.

I.E., “4WD” has become an almost meaningless marketing hype term, that isn’t clearly distinguished any more from AWD.

There at least used to be a lot of places you couldn’t legally go without 4WD (and in some cases, chains as well, but that’s irrelevant). I wonder how the ambiguity mentioned above folds into that.

And 2025 Venzas, if I understand correctly, have “AWD”, but, unlike mine, no center differential - they use an electric motor on the rear axle, when needed. And it is a hybrid, with separate electric motors on the two front wheels. I wonder if that means they have no front differential.

220

Unfortunately that is true, the marketing departments creat nomenclature problems.

221

An electric AWD system–an electrically driven rear diff with no mechanical connection to the front drivetrain–has been around for 20 years now. It’s beautifully simple and reliable.

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222

Pretty sure same power scheme as my 2025 Rav4. There are 3 motors; one powering the rear wheels, one power sharing with the engine for front wheels and the third one is used to start the engine on demand.

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Which is pretty much the same as the power scheme on a 2006 Highlander Hybrid. It’s a 20 year tried and true setup. So much so that Mazda is putting it in their CX-50 Hybrids.

1 Like