the higher the number the longer-lasting?
treadware rating no.s...
- Thread starter daves66nova
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in theory
theoretically. also gives an idea of how soft the rubber is. most track tires are in the 80 or less range, but they dont have to last more than a few thousand miles for an amateur racer.
It is said that you can't compare treadwear grades across manufacturers but you can within the brand. Capriracer posted some good information about this awhile back.
I guess I need to comment on this:
Mileage warranty is strictly a marketing tool. It is not based on anything tangible. I don't think anyone should use the mileage warranty as an indication of rate of tread wear.
Rate of tread wear: There are a lot of things that can influence tread wear, the largest is what I call "city" vs "country" driving. This is really the amount of turns you make compared to the amount of distance you travel in a straight line, and since most tire wear occurs in the cornering mode, you can get great wear if you don't make any turns. I've seen the cheapest of the cheap do almost 100,000 miles, simply because the vehicle they were on drove the freeway between cities 99% of the time.
Comparing the UTQG rating between tire brands: The problem here is that this is a really gray area. There is a government mandated test that everyone is supposed to use and it is a prescribed route and distance and the wear rate is supposed to be compared to a control tire. However, the tire on test may not be compatible with the control (different size, so the two test vehicles have to be different and that's not allowed), so the government allows a comparison between the control and a previously tested tire and then a comparison to the tire on test. This string can get quite long - so there is plenty of room for "fudging". Nevertheless, there is some basis to the UTQG number.
The second gray area is that the test result is an upper bound, and the manufacturer can use any number lower than that. And they do, generally for marketing reasons. An extreme example of this is a tire specially compounded for racing. They may assign a UTQG rating of 50 and not even test the tire.
The way I would phrase it is that the UTQG rating is as good a way of gauging tread wear as there is, and you can compare between brands, but you need to take it with a grain of salt - may be the whole shaker.
Also, have noticed that older designs still use UTQG number assigned when they were first introduced. New designs will have higher numbers assigned just to show that they are "better" when often the older design is as good and often better.
Back to the original question , pretty much a yes.
Bob
Back to the original question , pretty much a yes.
Bob
Good info from those folks floating above.
Another consideration is what part of the country you live/drive in.
Saw a map awhile back showing tire wear rates adjusted for geographical areas.
Appears that the type of crushed rock used in cement making affects tire wear. If I recall correctly, granitic-type rock causes more wear due to the components of that rock.
Wasn't a huge difference among geographical areas but it appears the differential exists.
Wondering about asphalt. Read that some area add ingredients to increase friction. Wasn't gound up glass or tires being used in some locales? Wonder of that could affect wear?
Another consideration is what part of the country you live/drive in.
Saw a map awhile back showing tire wear rates adjusted for geographical areas.
Appears that the type of crushed rock used in cement making affects tire wear. If I recall correctly, granitic-type rock causes more wear due to the components of that rock.
Wasn't a huge difference among geographical areas but it appears the differential exists.
Wondering about asphalt. Read that some area add ingredients to increase friction. Wasn't gound up glass or tires being used in some locales? Wonder of that could affect wear?
Since most tire wear occurs in the cornering mode, HOW you drive is really the biggest influence on what mileage you will get. Put another way, driving in a straight line extends tire life....turning doesn't. Needless to say, most of us can't really change this - we have to go where we have to go. But the folks who drive in the city don't do as well as those that live in the country.
Road surface has some affect, but as obbop said, it isn't a huge difference. This is mainly due this cornering effect. Many locales that have high abrasive surfaces also are remote, so the locals don't experience excessively rapid tire wear.
But one of the worst places for tire wear is southern Florida. The limestone used as aggragate is commonly refered to as "young", and the sea shells that make up the material are easily cleaved out the rock. The edges of these shells can be quite sharp, and tends to slice tiny bits of rubber off the tires, especially on newly paved concrete. After years of wear, the opposite happens and the road surface gets highly polished, which can be quite slippery.
I don't think adding glass or ground up tires really caught on. What I have seen is higher porosity surfaces, (larger aggragate) where water drainage is better and therefore the traction in wet conditions is better. It is generally a bit quieter, but this tire noise thing is so complex, it's hard to make definitive statements.
Yeah, down here in south FL, I noticed a lot of road surfaces, especially on local streets are very grainy, porous. Like you said, it helps with wet traction since we get quite a bit of rain, but driving on these surfaces generates a lot of noise.
Do different pavement compounds cause noticeable differences in fuel economy? Just curious...
Do different pavement compounds cause noticeable differences in fuel economy? Just curious...
If you are asking if different paving surface materials affect fuel economy, I think the answer is yes, but the effect is slight - which I will explain below.
If you are asking if different tread compounds affect fuel economy and that can be tied to the friction of the tire to the road surface.....ah..... it's more complicated than that.
The vast majority of resistance to rolling in a tire comes from friction within the tire itself.
This means the amount of deflection a tire experiences has a major effect - this equates to inflation pressure vs load.
This also means that the amount of material, especially material in the tread area, will also have a major effect. So All Terrain tires will have higher RR values than All Season tires - everything else being equal - which is usually not the case.
But the tread compound also has an effect. There are three properties that get traded off - RR, traction (especially wet traction), and wear. This means that tires that give good RR, generally don't have good traction or wear (or both), which is why you'll hear these types of complaints on Original Equipment tire, where the car manufacturers have to get CAFE fuel economy number and have the tires compounded to help.
High Performance tires generally have cap plies, which adds to the mass in the tread area, as well as having good traction compounds - which don't wear well and have poor RR values. I think this is where the myth of "friction with the road surface causes RR" comes from. The friction with the road surface contributes very little to RR compared to the deflection of the tire.
OK, now to the road surface.
Believe it or not, road surfaces flex under load - asphalt more than concrete. Needless to say this is very similar to what happens when a tire flexes, but to a much smaller degree since the deflection is much smaller. This should result in heat buildup in the road surface - and probably does, but I would think it would be so small that it would be difficult to measure.
And, of course, we can measure the heat build up in a tire by measuring the pressure buildup.
FWIW, and I don't know if it applies to rolling resistance and fuel mileage, but concrete roadways generally have a higher coefficient of friction vs asphalt.
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