How do you carry a spare tire?

Even that article you linked disputes what you say.

Towards the bottom of the article:
"If a difference is unavoidable, mount the smaller tire on the inside, Goodyear suggests. The outside tire wears faster than the inside tire. As it wears, its diameter will approach that of the inside tire. Additionally, any crown on the road will favor the placement of the smaller diameter tire on the inside." The bigger tire (because it has more tread) will wear faster than the smaller tire.

 

That’s what the tire tech said. Not my claim.

 

You keep asserting his claim as correct. That makes it your claim.

 

Fine. You can say it’s my claim, which I’m backing up with a tire tech. It’s an argument from authority. And I also posted an article to further support my “claim.” More on that on a different post.

 

Set my reply to the article you posted. In a paragraph tries the bottom it literally disputes the claim you are making.

 

So what’s apparently going on is that excessive tire wear can happen to both the taller and shorter tires in particular situations.

From the article:

“...As we've already explained, the taller of the two tires will suffer a greater degree of sidewall damage because it's taking up more of the load. The shorter of the two will experience more irregular tread wear due to excessive scrubbing.”

“‘When you have two tires, one taller than the other, rotating around the same pivot point, the shorter tire will scuff its way along the road because its tread passes a point on the ground at a faster rate relative to the larger tire,’ explains Rick Phillips, manager of commercial tire sales at Yokohama Tire.”

 

I figured out years ago, if you have much wear on your tires at all, and do not have a used one that matches, it is cheaper to buy 2 tires than one.

 

What kind of junk were you running? I've had so many caps let go, I can't remember them all, but in all my miles, I don't ever remember blowing out a virgin tire. It's why I ran virgins on all my tractors.

 

What causes this is the taller (more tread) tire is rolling faster than the smaller tire. Since the taller tire has more weight on it, it carries more traction than the smaller tire, which causes the shorter tire to scrub.

All that being said, I haven’t seen noticeable damage in 100 miles. I just put the spare on, not worrying about matching tread depth, and fix it at my next available opportunity. Maybe it’s causing a little more wear, but it’s not readily noticeable.

Edit- I should clarify, both tires are turning at the same RPM, but the circumference is traveling at different speeds ( due to the difference in size).