UTQG temp question.....

[daves87rs]

On an all season tire with a A rating for temp (like the CS4 or the General Altimax) compare to say a tire with a B rating (Like the GY Assurance, Mich Defender)...when it comes to a smaller size tire (13,14,15)?

Many tires I see have A B ratings, but very few have the A A ratings like the bigger sized tires do.....

 

[jorton]

Here is one 15" with A A rating and here is another.

 

[KB2008X]

First off, when tires are tested by the tire manufacturers the tire is spun against a metal drum in a controlled environment - it is not a car and not on the road.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=48

A larger tire has more surface area than a smaller tire and is better able to release the heat generated, so it naturally has a better rating.

Larger tires are built for heavier loads and will generally be built with better materials and/or better processes, and theoretically, at least, will do better dealing with heat. Furthermore, most small tired cars are econo cars and the owners are more sensitive to price and typically won't pay more for a better tire. They're happy with cheap tires and don't push the performance envelope of their tires anyhow. So, there is no incentive for tire manufacturers to build small tires with great ratings.

Be aware that you can't compare UTQC ratings from one tire manufacturer to the next.

Keith

 

[CapriRacer]

Originally Posted By: KB2008X
......Be aware that you can't compare UTQC ratings from one tire manufacturer to the next.

Keith


I've pointed this out before, but because the testing is the same for every tire manufacturer, you CAN compare. You have to be especially careful with the treadwear rating. Unlike the other ratings, where the grading system is quite coarse, the treawear rating has very small increments and the testing is quite variable, that presents the opportunity to play games with the numbers.

So be cautious when comparing treadwear ratings. Small differences (say 10%) are insignificant.


Originally Posted By: daves87rs
On an all season tire with a A rating for temp (like the CS4 or the General Altimax) compare to say a tire with a B rating (Like the GY Assurance, Mich Defender)...when it comes to a smaller size tire (13,14,15)?

Many tires I see have A B ratings, but very few have the A A ratings like the bigger sized tires do.....


The temperature rating is more or less a speed rating.

Nowadays, smaller rim diameters are only found on older cars - and cost, not performance is the major factor when purchasing these sizes. So these tires tend to use lower speed ratings.

 

[daves87rs]

Originally Posted By: CapriRacer
Originally Posted By: KB2008X
......Be aware that you can't compare UTQC ratings from one tire manufacturer to the next.

Keith


I've pointed this out before, but because the testing is the same for every tire manufacturer, you CAN compare. You have to be especially careful with the treadwear rating. Unlike the other ratings, where the grading system is quite coarse, the treawear rating has very small increments and the testing is quite variable, that presents the opportunity to play games with the numbers.

So be cautious when comparing treadwear ratings. Small differences (say 10%) are insignificant.


Originally Posted By: daves87rs
On an all season tire with a A rating for temp (like the CS4 or the General Altimax) compare to say a tire with a B rating (Like the GY Assurance, Mich Defender)...when it comes to a smaller size tire (13,14,15)?

Many tires I see have A B ratings, but very few have the A A ratings like the bigger sized tires do.....


The temperature rating is more or less a speed rating.

Nowadays, smaller rim diameters are only found on older cars - and cost, not performance is the major factor when purchasing these sizes. So these tires tend to use lower speed ratings.



That's kinda what I thought, but I figured I ask just to be sure. Thanks Capri!

 

[Hokiefyd]

Originally Posted By: KB2008X
Be aware that you can't compare UTQC ratings from one tire manufacturer to the next.


"U" in UTQG (and it's UTQG, not UTQC) stands for "Uniform", meaning the same testing procedures are performed on all tires. By their nature, they are designed to be a uniform grading scale.

 

[Quattro Pete]

Originally Posted By: Hokiefyd
"U" in UTQG (and it's UTQG, not UTQC) stands for "Uniform", meaning the same testing procedures are performed on all tires. By their nature, they are designed to be a uniform grading scale.

That may have been the intent, but there is plenty of wiggle room there, if you've read the TireRack text linked to above...

Quote:
The problem with UTQG Treadwear Grades is that they are open to some interpretation on the part of the tire manufacturer because they are assigned after the tire has only experienced a little treadwear as it runs the 7,200 miles. This means that the tire manufacturers need to extrapolate their raw wear data when they are assigning Treadwear Grades, and that their grades can to some extent reflect how conservative or optimistic their marketing department is. Typically, comparing the Treadwear Grades of tire lines within a single brand is somewhat helpful, while attempting to compare the grades between different brands is not as helpful.

 

[Hokiefyd]

Originally Posted By: Quattro Pete
That may have been the intent, but there is plenty of wiggle room there, if you've read the TireRack text linked to above...


Tire Rack's article is talking about tread life. This thread (and the context of the comment about UTQG being brand-specific) is about the UTQG temperature grade.

 

[Quattro Pete]

Gotcha.

I've seen Capri talk about treadwear above, so I assumed we were discussing UTQG as a whole.

 

[CapriRacer]

I disagree with what Tire Rack has published.

They have over-emphasized the differences between brands. If you take what they are saying lierally, then Brand X with a 400 UTQG Treadwear rating can't be compared to Brand Y with a 500 UTQG rating.

- and I say that's a significant enough difference to conclude that Brand Y is going to deliver more miles before it has to be removed due to wear. It might not be 25% more, but it is certainly not like the reverse would be true.