In Depth Tire Explaination

[360kid]

I'm looking to get some in depth knowledge on tires. I'm looking at a set of General RT43. They come in various speed ratings of T, H, or V and are all about the same cost, within a couple of dollars of each other. So, what is the difference?

First, I know what the speed ratings of T, H, and V refer to, no need to chime in on that. What I really want to know is what does the manufacturer, in this case General, do differently to achieve the different speed ratings on tires that for all intents and purposes... look identical?

Would the H and V tires have a grippier compound? Stiffer sidewalls? Less sidewall squat? Are the H and V tires only better in dry traction but worse in wet and light snow? Which tire would have better light snow traction for the bumper months?

Basically, if you have seemingly identical RT43 tires for identical price, but one set is rated for 118 mph and the other 130 mph, I want to know what that actually means in terms of tire characteristics and how that translates to 3 season driving.

 

[raytseng]

It can just be trade secrets from the Tire manufacturer, as the rating does't require any differences other than certification for that speed and they don't need to say what they did differently.

One time, a tire rep told me that some of the close ratings don't reflect any change in construction. Rather it is just due to binning like computer cpus.

Midway through the tire manf. process, the carcasses that were inspected to be the most true were going to be stamped Z, then the ones that were a little flawed they'd do V, and more flawed they'd do H. If it was too flawed it would be rejected.

So potentially if the manufacturing was all perfect for a day they'd just make some of the carcasses H's even though they could be good enough to be Vs. And they'd just sell them because that's what the market calls for some H's.

But this could've just been a single case or an urban legend and only true say for the upper end like H vs V; and not when you go lower to the budget rating like a T. There could also other models or manufacturers don't follow this strategy and actually have construction or compound differences between the speed ratings even for the same make/model.


I believe in general the highest rated tire (Z or V) should have zero tradeoffs compared to getting the (H) tire other than being priced higher. You won't get a cushier ride on the same make/model.
In reverse, if you get the lower "H" "maybe" it will be just as good as the V/Z if you believe the story above.

 

[eljefino]

Believe capriracer mentioned the 130 mph rating includes a cap ply, an important consideration in construction that you generally want.

 

[EdwardC]

Take a look here: http://www.barrystiretech.com/speedratings.html

About 3/4 of the way down, they talk about the jump to H rated tires typically needing an additional cap ply. It talks about how the speed capabilities of a tire decrease with age, but I don't know what the effect of the T vs H rated tires assuming they are both fresh.

I do think that the additional ply is in the tire, at least in the case of T and H. If you go to General's site, the T rated tire has a different weight than the H rated tire of the same size. http://generaltire.com/tires/passenger-and-minivan/altimax-rt43

 

[raytseng]

If the tire specs are difference, either with weight, or tread warranty or dimensions; then for sure there's a difference in construction.
It may also be listed as a completely different item on tirerack as the warranty or description has differences in text.

But on tirerack, Often you see H and V are listed under same item, and only differ in price by $4. If you see that, then it starts becoming a possibility that between H and V is the same construction specs (although might still be different from the binning I said above).

 

[eljefino]

Originally Posted By: raytseng

But on tirerack, Often you see H and V are listed under same item, and only differ in price by $4. If you see that, then it starts becoming a possibility that between H and V is the same construction specs (although might still be different from the binning I said above).



You need to come up with some proof for this statement.

 

[360kid]

Originally Posted By: EdwardC
Take a look here: http://www.barrystiretech.com/speedratings.html

About 3/4 of the way down, they talk about the jump to H rated tires typically needing an additional cap ply. It talks about how the speed capabilities of a tire decrease with age, but I don't know what the effect of the T vs H rated tires assuming they are both fresh.

I do think that the additional ply is in the tire, at least in the case of T and H. If you go to General's site, the T rated tire has a different weight than the H rated tire of the same size. http://generaltire.com/tires/passenger-and-minivan/altimax-rt43


Reading Barrys Tire Tech article explains a lot. From reading that article, I would hypothesize that all of General's RT43 tires are identical in terms of tread and compound. The difference being that they added an extra layer, "Cap Ply," to the H and V tires in order to get them to pass at the higher speed rating. If my guess is correct, there would be no reason to buy the T rated tires. The H rated tire is more than likely just the same tire with the extra ply inside.

I wonder why the the T rated tire would have a longer warranty? It's 75,000 miles vs 60,000 miles on the H and V. Perhaps the longer warranty is just a marketing attempt to sell more T speed tires.

 

[bvance554]

The RT43's have gotten a lot of great press around here, and I put a set on my Cruze based on that. After 10k I'm not THAT impressed with them. They're ok... Very good in the rain. I have yet to experience them in the snow. But they're loud, my mpg has decreased more than 10%, and they just don't grip that well on dry pavement. I put a set of Kumho's on my son's Passat. They were slightly cheaper, have a much lower treadwear rating than the RT43's, but they ride and handle so much better.

 

[CapriRacer]

As a general rule, S rated tires do not need any cap plies, T rated tires need cap strips over the belt edges (but that will not appear on the sidewall as an additional ply), H rated tires need a single cap ply, V rated tires need 2 cap plies, and W,Y and Z rated tires need 2 cap plies and cap strips.

Again, that is a general rule, and there are plenty of exceptions.

Also, there is no reason why any tire would have a different tread compound simply because of the speed rating - except to say that winter tires would be an exception. HOWEVER, it is fairly common for higher speed rated tires to be designed more for grip than for wear - and that would require different tread compounds, and that would result in a different mileage warranty.

Also, it is fairly common for higher speed rated tires to be designed for better handling, and that would require a high filler in the bead area. There is no way to know if this difference appears in a tire or not, unless you cut the tire open. Again, this varies a lot and is not directly tied to speed rating.

In this case, the General Tire Altimax RT43 has the same mileage warranty regardless of speed rating, so it is very, very likely that the tread compound is the same throughout the line. It is also likely that entire line was designed with the same bead filler arrangement.

 

[stephen9666]

All the name-brand t-rates tires I've bought or considered in the last several years had a cap ply. That includes Hankook H727, Kumho KR21 and Cooper CS5 Grand Touring.

 

[360kid]

Originally Posted By: bvance554
The RT43's have gotten a lot of great press around here, and I put a set on my Cruze based on that. After 10k I'm not THAT impressed with them. They're ok... Very good in the rain. I have yet to experience them in the snow. But they're loud, my mpg has decreased more than 10%, and they just don't grip that well on dry pavement. I put a set of Kumho's on my son's Passat. They were slightly cheaper, have a much lower treadwear rating than the RT43's, but they ride and handle so much better.


I have ran the General Altimax Arctics before based on reviews. Tire Rack really talks up the General tires. At first, I thought they were great, probably due to the excitement of the purchase and the honeymoon phase. By halfway through the first winter, I thought they were quite mediocre. After two winters, I gave them away less than half worn.

Tire Rack again is leading me to believe the RT43 are awesome tires and handle pretty good in the snow for an All Season. So, I am strongly considering them. Your comment makes me wonder if I'll just be disappointed again as I was with the Altimax Artics.

 

[Cressida]

Originally Posted By: stephen9666
All the name-brand t-rates tires I've bought or considered in the last several years had a cap ply. That includes Hankook H727, Kumho KR21 and Cooper CS5 Grand Touring.


A couple of points to consider:

1. I have seen examples of the same brand / model of a tire that may have a cap ply in a specific tire size yet a different tire size (in same model name AND speed rating) may not have the cap ply. (This is based off of reading the sidewalls about the tire construction)

2. The Consumer Reports test and reviews of the RT43 show the tire in the "T" speed rating to have better snow traction than does this tire in the "H" or "V" speed ratings. Nevertheless from what I've read, tread compound does not make much difference in snow traction - it is largely based on the tread design.

 

[360kid]

Originally Posted By: Cressida
Originally Posted By: stephen9666
All the name-brand t-rates tires I've bought or considered in the last several years had a cap ply. That includes Hankook H727, Kumho KR21 and Cooper CS5 Grand Touring.


A couple of points to consider:

1. I have seen examples of the same brand / model of a tire that may have a cap ply in a specific tire size yet a different tire size (in same model name AND speed rating) may not have the cap ply. (This is based off of reading the sidewalls about the tire construction)

2. The Consumer Reports test and reviews of the RT43 show the tire in the "T" speed rating to have better snow traction than does this tire in the "H" or "V" speed ratings. Nevertheless from what I've read, tread compound does not make much difference in snow traction - it is largely based on the tread design.


I did see that the T rated tires performed differently that the H, V... I just subscribed to Consumer Reports last night myself. I would disagree about the compound for snow. The tire compound of studless snow tires is completely different from All Season and Summer tires. From my experience, you really cannot judge a winter tire by tread pattern. It really is the compound and sips that make the tire. If it really was tread pattern, then Firestone Winterforce would be the best snow tire available due to it's aggressive pattern, but in reality it is one of the absolute worst winter tires.



I ended up ordering the Continental True Contact DWS (Dry, Wet, Snow) tires. They were $98 a tire and seemed to have the best dry, wet, snow balance I could find according to Tire Rack and Consumer Reports. I typically run summer and winter, but both sets are worn out and I really didn't want to buy a new set of summer and winter tires for a car that is worth $1600 and are planning to dump it next spring/summer. So, I was trying to find a compromise of an All Season that would also be safe for 35 mile winter commute.

 

[raytseng]

Originally Posted By: Cressida
Originally Posted By: stephen9666
All the name-brand t-rates tires I've bought or considered in the last several years had a cap ply. That includes Hankook H727, Kumho KR21 and Cooper CS5 Grand Touring.


A couple of points to consider:

1. I have seen examples of the same brand / model of a tire that may have a cap ply in a specific tire size yet a different tire size (in same model name AND speed rating) may not have the cap ply. (This is based off of reading the sidewalls about the tire construction)

2. The Consumer Reports test and reviews of the RT43 show the tire in the "T" speed rating to have better snow traction than does this tire in the "H" or "V" speed ratings. Nevertheless from what I've read, tread compound does not make much difference in snow traction - it is largely based on the tread design.



Regarding the snow traction. Often times when they do a review that spans different ratings, that means they tested across different cars which often means they tested across different sizes. Since the H or V Rated tires are typically specced for sportier cars, the chosen dimension for that test is typically fatter.
Since T are tires specced for econoboxes they are typically are skinnier tires to be tested on a econobox.

So for the snow test, the skinny T tire may do better than a fatter H or V entirely due to the sizing.

Even Tirerack has this comparison problem too, if you try to read their reviews of a All-Season Shootout vs the UltraPerformance Allseason. If the 2 shootouts use a different car and tire size, you can't compare tires that cross two different shootouts or 2 different tire categories if the tests change the size.

I think though if it were apples/apples then you wouldn't be giving up anything by going with the Higher V or H except the $.

 

[raytseng]

360 kid:

Did you get the DWS or the newer DWS06? Supposedly the newer tire is better than the old without any tradeoffs.

 

[HTSS_TR]

Originally Posted By: raytseng
Even Tirerack has this comparison problem too, if you try to read their reviews of a All-Season Shootout vs the UltraPerformance Allseason. If the 2 shootouts use a different car and tire size, you can't compare tires that cross two different shootouts or 2 different tire categories if the tests change the size.

I think though if it were apples/apples then you wouldn't be giving up anything by going with the Higher V or H except the $.

I agree.

Only valid comparison is within a shootout.

 

[stephen9666]

Originally Posted By: raytseng

Regarding the snow traction. Often times when they do a review that spans different ratings, that means they tested across different cars which often means they tested across different sizes. Since the H or V Rated tires are typically specced for sportier cars, the chosen dimension for that test is typically fatter.
Since T are tires specced for econoboxes they are typically are skinnier tires to be tested on a econobox.

So for the snow test, the skinny T tire may do better than a fatter H or V entirely due to the sizing.


Your assumptions are incorrect in this case.

CR lists the size they test for each tire. It appears they generally choose common sizes for testing for this exact reason. I'm a subscriber, so I just checked.

The CS5 GT (T rated) and the CS5 UT (H and V rated) were all tested in the same size, 215/60-16.

EDIT - CR says all of the the all season and performance all season tires tested were 215/60-16
Quote:
All Season and Performance All Season tires were tested in a 215/60R16 size.


The ultra high performance tire category looks like they used the size 225/40-18

 

[Darris]

Originally Posted By: 360kid
... I would disagree about the compound for snow. The tire compound of studless snow tires is completely different from All Season and Summer tires. From my experience, you really cannot judge a winter tire by tread pattern. It really is the compound and sips that make the tire. If it really was tread pattern, then Firestone Winterforce would be the best snow tire available due to it's aggressive pattern, but in reality it is one of the absolute worst winter tires
.


I think you're blurring two different elements of Winter performance. Tread pattern is paramount to SNOW traction specifically, whereas special winter compounds are used to improve traction on ICE & frozen pavement. Although I do recall reading something about the differences of Hydrophilic vs Hydrophobic compound as it could relate to snow traction, in fact the tread does the heavy lifiting.

A relative had WinterForce tires on his wagon form 2011-2014 which I drove a few times and indeed they are extremely good tires in deep, fresh snow with mild temps, but on frozen snow, ice or extremely low temps they are horrible, in fact worse than most all seasons because the voids work against traction in those conditions.

Quote:

I ended up ordering the Continental True Contact DWS (Dry, Wet, Snow) tires. They were $98 a tire and seemed to have the best dry, wet, snow balance I could find according to Tire Rack and Consumer Reports..


You probably got the slightly better tires overall. These are two of the better snow-biased all-seasons available at a moderate prce (althhough a couple of BITOG'ers swear by Pirelli P4 ) just don;t expect miracles on ice or frozen snow.

 

[Darris]

Originally Posted By: raytseng
360 kid:

Did you get the DWS or the newer DWS06? Supposedly the newer tire is better than the old without any tradeoffs.



DWS6 is the successor to the original DWS, However I think Continental is now adding the"DWS" as a marketing designation to some other all-season models. The True Contact & Pure Contact are a totally different product offered at broader range of price points, speed ratings and sizes than the original DWS.

 

[Rand]

What tire did you get I dont see any true contact with DWS?

I do see EWC DWS and EWC DWS06 models.

Its like you combined 2 different model names or I am missing something?