Ride quality difference in a H rated tire vs a V?

Status
Not open for further replies.
Originally Posted By: CapriRacer
Originally Posted By: GC4lunch
The European speed system is a rating that is the same as the Temperature rating in the American Uniform Tire Quality Grading mandated by the NHTSA. It is a measure of one thing, and one thing only: the maximum temperature to which a properly inflated tire, loaded within its load limitations can attain before it will explode.


I'm sorry, but that is not correct.


I am not going to disagree with you, because I think that we are saying the samee thing from different directions. After I had posted the above, I attempted to revise it -- but was outside the short revision time period -- to say "... the maximum rotations per minute that a properly inflated tire, loaded within its load limitations can sustain before it attains an internal temperature that will cause it to explode ..." It is the speed that causes the temperture rise, and it is the temperature that causes the catastrophiic failure, but the causal chain is seamless.

Originally Posted By: CapriRacer
Both the speed rating and the UTQG Temperature ratings are not tied to temperature.

I diasgree; you are incorrect. The reason that the UTQG criterion is called the "Temperature rating" is because it is tied to temperature. The test procedures of both ratings systems are the same: running a tire against a rotating steel drum of specified diameter at a specified number of rotations per minute for a specified time period. If the tire fails before the end of the time period, the speed rating is not achieved.

Now, to design a tire that will pass the test, the tire manufacture can follow either or both of two strategies: it can design the tire to dissipate the heat that is generated more efficiently, or it can design the tire to withstand greater temperatures before the tire fails. Both strategies are directly related to temperature.

Originally Posted By: CapriRacer
Both tests are about the maximum speed a tire can attain before failure - and failure doesn't mean a loss of inflation pressure. It means loss of casing integrity. Typically, the failure is a "belt-leaving-belt" separation - and the air chamber is still intact.

In real-world conditions -- on the road, rather than in the testing chamber -- delamination is followed almost instantaneously by a loss of integrity of the air chamber: delamination on the road is followed so closely by explosion of the tire that they effectively are a single event.

Originally Posted By: CapriRacer
Originally Posted By: GC4lunch
..... The S, T, H, V, Z speed ratings simply indicate how many rotations per time period the properly inflated, not overloaded, tire can sustain before it will explode; the speed ratings mean nothing more or less than that......


In some repects that is correct, but more accurately, the speed rating is the speed that the tire can attain before failure. The tests are step speed tests, where the tire is subjected to increasing speed in a series of steps. You could look at that as either time or revolutions, but that's because the test has that defined, but the way this is always reported is a speed.


The way it is reported is as a grade: C, B, or A for the UTQG, or S T, H, V... for the ECE speed ratings. The ECE speed ratings provide a table for the maximum vehicle speed associated with each letter, but that table is a translation of revolutions per minute when the tire is run against the steel drum in the lab, using a mathematical formula. The tire under test in the lab is applied to an axle that is stationary; no actual speed is involved.

Originally Posted By: CapriRacer
Temperature is NOT the criteria used to determine the speed rating.

I am sorry, but that is nonsensical: the tire fails when it attains a temperature that exceeds its design parameters to dissipate heat or when the heat reaches a temperature where it exceeds the tire's design parameters to retain integrity. The temperature need not be measured in degrees, because the temperature is more directly measured by the tire's failure, but temperature ultimately is the only criterion used to determine the speed rating.

Originally Posted By: CapriRacer
Originally Posted By: GC4lunch
.... Obviously a stiffer sidewall will flex less than a more flexible sidewall, for instance, and rayon carcass plies will generally perform batter than polyester carcass plies........


I disagree. There are a number of different materials that could be used for the plies, but they don't impact that speed rating. The casing is the same for an S rated tire and an H rated tires. The difference is the cap plies.

Here we have a direct disagreement. Rayon is superior to polyester as a material for tires because of its linear characteristics over a wider range of temperatures than polyester. Again, temperature is the crucial factor. The number of cap plies is not specified in either the European or the NHTSA speed rating rules or testing procedures, and there is an implication in the ECE-30 language that (theoretically, at least), a bias ply tire with no cap plies could achieve any speed rating.

Originally Posted By: CapriRacer
Originally Posted By: GC4lunch
....... But there are no hard and fast rules. For example: the Continental ExtremeContact DW tire has a single polyester ply carcass construction, and has a relatively flexible sidewall therefore, and a relatively soft ride; but the 'DW is a Z-rated tire, albeit a tire that never, ever, should be driven underinflated, because it heats up very rapidly when driven at high speed when underinflated......


I think you will find that the larger tires will have 2 plies regardless of the tire line - and by larger, I mean load carrying capacity - and Load Index is a short cut to that value.

Actually, the tire I used as an illustrative example, the Continental ExtremeContact DW, has high specified load levels compared to other tires of similar sizes. It has a single sidewall ply.

Originally Posted By: CapriRacer
... in order to pass the higher speed ratings, the tire has to have more cap plies. You could call it a "Rule of Thumb", but it's a generalization about how things are currently done.

Now you're just making things up.
 
Originally Posted By: CapriRacer

I was going to respond to each of those inserts......

Please proceed.

Originally Posted By: CapriRacer
Before I do. we need to know what sort of consulting you did with the tire industry.

No you don't. Apparently like you, I am an independent contractor; no one client pays me a salary, and I work on a fee basis; all of my book of business comes from direct referrals from existing clients. In common with you, my clients are very protective of the confidentiality of our relationship; I am very solicitous of my clients' desire for confidentiality, and thus resist any impulse to compromise the trust that my clients have placed in me.

Originally Posted By: CapriRacer
... here are my credentials:

http://www.barrystiretech.com/credentials.html

Very impressive; I will readily concede that your credentials outgun mine, at least for breadth.

Originally Posted By: CapriRacer
Any questions?

Yes; will you now address the issues of my last post?
 
Originally Posted By: GC4lunch
....Will you now address the issues of my last post?


The reason I asked for your background is that what you have been posting was either incorrect or totally different than my experience.

I am still unconvinced you have the technical background in tire engineering to be able to make the statements about tire construction - that is, whether cap plies are what drives speed capability and not body plies.

The problem here is that I don't know of a source that lists the construction for lines of tires - so I'm not going to be able to prove my point in this area by citing examples.

It also means you can't either.

But we can talk about Speed Ratings and the UTQG "Temperature" test. Those procedures are published and we should be able to find them on-line.

So the first part is for us to agree that neither the Speed Rating tests nor the UTQG "Temperature" test are "test to failure" type tests. They are a "test for compliance" and the only criteria is successfully passing a certain step in the test. The tests aren't designed to test capability. The result of the test would be either a failed tire (and the tire fails the test) or an unfalied tires (and the tire passes the test).

Put a different way, the tire manufacturer desires a certain Speed rating or a certain "Temperure Rating" and if the tire passes that particular step in the test, the test is over.

Are we still on the same page?
 
Just to inject my practical experience with the Primacy MXV4 on a V6 Accord, here's my experience. After removing the horrible riding (on this car) Conti Extreme DWS after 30 days because of flat spotting I traded for the spec V rated Primacy MXV4 at Discount Tire. I've been very satisfied with the tire's ride and performance. I suppose I could have gone with the H rated Primacys looking for perhaps a better (softer?) ride, but in the MXV4's, the H rated version on Tire Rack is ~$100 more for a set of four. Sticking with the spec V rated has worked fine for me.

That said, on other vehicles like a Civic with an H speed spec I've had success using S and now T rated tires with the Yoko Avid Touring S.

Let the interesting technical discussion/debate continue.
 
Sayjac....do I read correctly:

"...I traded for the spec V rated Primacy MXV4 at Discount Tire.....I could have gone with the H rated Primacys looking for perhaps a better (softer?) ride, but in the MXV4's, the H rated version on Tire Rack is ~$100 more for a set of four."

I'm new to Michelin's tire models soooo this question....

...the "H" is MORE than the same "V" rated tire?

Thanks for educating my confusion...
 
Last edited:
Originally Posted By: KitaCam
Sayjac....do I read correctly:

"...I traded for the spec V rated Primacy MXV4 at Discount Tire.....I could have gone with the H rated Primacys looking for perhaps a better (softer?) ride, but in the MXV4's, the H rated version on Tire Rack is ~$100 more for a set of four."

I'm new to Michelin's tire models soooo this question....

...the "H" is MORE than the same "V" rated tire?

Thanks for educating my confusion...

I just went to the Discont Tire website and in the 215/55/17 size that fits 2007-2011 Camry SE & 2012 Camry SE I4 & XLE I4 & V6, the H rated Primacy is $165 and the V rated Primacy is $180. I run H rated Primacys in that size and LOVE THEM.
http://www.discounttire.com/dtcs/filterT...ca&toggled=

(PS ….. don’t you use your same handle over on ToyotaNation?)
 
Originally Posted By: KitaCam
Sayjac....do I read correctly:

"...I traded for the spec V rated Primacy MXV4 at Discount Tire.....I could have gone with the H rated Primacys looking for perhaps a better (softer?) ride, but in the MXV4's, the H rated version on Tire Rack is ~$100 more for a set of four."

I'm new to Michelin's tire models soooo this question....

...the "H" is MORE than the same "V" rated tire?

Thanks for educating my confusion...

On TR in the spec size for my 3.0L V6, the 215/50-17, it's a $104 difference to be exact, $656 vs $760 for H rated. Also checking Discount Tire, the H rated is $7 list more per tire than V rated, one 'might' be able to negotiate that to same price at a DT b&m store. No V rated on DT Direct but the H rated MXV4 is the highest priced tire in that size. So, while that may not be true for all sizes, it is true in this instance, I wasn't going to pay more for what 'might' have been a softer ride with a lower speed rated tire. YMMV, check your size.
 
Wonder if there was a "special purchase" of V rated Primacys or something in your size sayjac. Or more likely, Tirerack made a mistake in your favor since our sizes are so close.

For the heck of it, I went onto tire rack and in my size 215/55/17 the difference is even more pronouced than that of Discount tires I mentioned above as follows:

Primacy MXV4 H rated set of 4 $626
Primacy MSV4 V rated set of 4 $796
 
Last edited:
Originally Posted By: CapriRacer
. . . whether cap plies are what drives speed capability and not body plies.

I have not intentionally made any claims about what tire architecture drives speed capability; I did react indirectly to a statement upthread that seemed to imply that there is a lock-step relationship between the number of cap plies and the ECE speed rating of a tire. Were that the case, high performance tires soon would begin to look like this. Moreover, I think you will agree that the cause of heat build-up is flexing within the tire; or do you disagree on that point?

Originally Posted By: CapriRacer
The problem here is that I don't know of a source that lists the construction for lines of tires - so I'm not going to be able to prove my point in this area by citing examples.

It also means you can't either.

I know of no compilation in one location that sets out the construction details of all brands and lines of tires. (If there were one, it wold be a bear to maintain, as new lines are introduced all the time.) However, it is possible to talk about specific lines of tires (as I did above with the Continental ExtremeContact DW) for which the construction is known.

Originally Posted By: CapriRacer
But we can talk about Speed Ratings and the UTQG "Temperature" test. Those procedures are published and we should be able to find them on-line.

I provided a link earlier to a recent publication of ECE-30; the UTQG test procedures are in the Code of Federal Regulations here. The numbering scheme (the hierarchy of subsections and sub-subsections, etc.) that the government uses makes citation difficult -- I once noted in a published article that an FTC regulation that was intended to be useful to consumers did not function as a sentence in the English language -- but the content is all there.

Originally Posted By: CapriRacer
So the first part is for us to agree that neither the Speed Rating tests nor the UTQG "Temperature" test are "test to failure" type tests. They are a "test for compliance" and the only criteria is successfully passing a certain step in the test. The tests aren't designed to test capability. The result of the test would be either a failed tire (and the tire fails the test) or an unfalied tires (and the tire passes the test).

Put a different way, the tire manufacturer desires a certain Speed rating or a certain "Temperure Rating" and if the tire passes that particular step in the test, the test is over.

We have no disagreement on that point whatsoever, but I point out that it is a distinction without a difference. Consider the pole-vault competition in track & field. When the pole-vaulter clears a certain height without knocking off the horizontal bar, he or she has passed that height, a "test to compliance." The bar is then raised to a higher position, and the pole-vaulter attempts to clear the latter height. If he or she succeeds -- another "test to compliance" -- then the new height is the only level recorded for that vaulter for the event; if he or she fails, then the lower height is recorded for that vaulter the event. Is pole-vaulting a "test to compliance" event or a "test to failure" event?
 
Not sure why the V rated tire is less in that size, but seeing as the H rated is also more at Discount Tire, (though not as much difference as TR) I'm not inclined to think it's an error by TR.

Also, I didn't purchase the tires from TR, but at Discount Tire as part of a trade for the Conti DWS's I referred to in my original post here. At that time too, the H rated MXV4 was more expensive than the V rated tire at DT. Apparently other factors beyond speed rating like supply and demand, can determine prices of a tire. fwiw, I only use TR as a possible price match reference when buying tires from Discount Tire.
 
I got the V rated Primacy's put on the Accord for 61 dollars more than I paid for the GY Comforttreds. They matched Tread Depot's price of $568 and it was free shipping as well for that price. (Also have the 70 dollar Michelin rebate coming as well)

Gotta say initially these are a pretty smooth riding tire. Not sure how much softer the ride would be with the H version but after 2 days riding on these I gotta say they are nice.

I'll be giving a more detailed review in a day or so once I get some miles on them. I took a ride down to Boch Honda West today and was happy at the noise and comfort level of the tire



Goose
 
Originally Posted By: HerrStig
Originally Posted By: friendly_jacek
Way too much B.S. in this thread. Speed rating has nothing to do with sidewall stiffens and everything to do with a nylon cap.
That's nice, but when you actually LOOK at the differences in tire models which come in several speed ranges you discover that the sidewall construction is often different as well.

I made a discovery this weekend, in costco's tire shop I compared the sidewall construction between the H and V rated MXV4. The V-rated tire has 1-ply and the H-rated has 2-ply. I would have thought it would have been the other way around?
 
thanks for all the info. I literaly went and put a bag of Orville Redenbacker Movie Theater Butter single serve in the microwave, thanks Capri & GC4lunch for the spirited & sensible discussion. The popcorn made it even better,
 
Originally Posted By: Colt

I went with H rated Michelin Primacy MXV4's on my Lexus a month after I got it.
Got rid of the V rated horrible ride and noise of Bridgestone Turanza EL 400's.


That's not a fair comparison between OEM V vs one of the most expensive aftermarket H.
 
Originally Posted By: ottomatic
thanks for all the info. I literaly went and put a bag of Orville Redenbacker Movie Theater Butter single serve in the microwave, thanks Capri & GC4lunch for the spirited & sensible discussion. The popcorn made it even better,


I did a little research and found out that what I thought was pretty much true, isn’t.

The gist is that for polyester tires, the number of cap plies is pretty close to what I stated

- BUT –

For rayon tires, it’s different – and different in a way that is difficult to state. Plus there are some other quirk’s I uncovered in my research.

So GC4Lunch was correct in his challenge.
 
Originally Posted By: CapriRacer
Plus there are some other quirk’s I uncovered in my research.

You have piqued my curiosity. What quirks did you uncover?

For the convenience of the Orville Redenbacker munchers, I excerpted from the tedious NHTSA UTQG regulation the essence of the Temperature testing procedure, which I quote below.

Originally Posted By: National Highway and Traffic Safety Administration


(g) Temperature resistance grading. (1) Mount the tire on a rim of design or measuring rim width specified for tires of its size in accordance with § 571.109, paragraph S4.4.1 (a) or (b) and inflate it to the applicable pressure specified in Table 1 of this section.

(2) Condition the tire-rim assembly to a temperature of 95 °F for at least 3 hours.

(3) Adjust the pressure again to the applicable pressure specified in Table 1 of this section.

(4) Mount the tire-rim assembly on an axle, and press the tire tread against the surface of a flat-faced steel test wheel that is 67.23 inches in diameter and at least as wide as the section width of the tire.

(5) During the test, including the pressure measurements specified in paragraphs (g) (1) and (3) of this section, maintain the temperature of the ambient air, as measured 12 inches from the edge of the rim flange at any point on the circumference on either side of the tire at 95 °F. Locate the temperature sensor so that its readings are not affected by heat radiation, drafts, variations in the temperature of the surrounding air, or guards or other devices.

(6) Press the tire against the test wheel with a load of 88 percent of the tire's maximum load rating as marked on the tire sidewall.

(7) Rotate the test wheel at 250 rpm for 2 hours.

(8) Remove the load, allow the tire to cool to 95 °F or for 2 hours, whichever occurs last, and readjust the inflation pressure to the applicable pressure specified in Table 1 of this section.

(9) Reapply the load and without interruption or readjustment of inflation pressure, rotate the test wheel at 375 rpm for 30 minutes, and then at successively higher rates in 25 rpm increments, each for 30 minutes, until the tire has run at 575 rpm for 30 minutes, or to failure, whichever occurs first.

Annex 7 of ECE-30, the European Speed Ratings test cited in message #2812076 above, is very similar.
 
Originally Posted By: GC4lunch
We have no disagreement on that point whatsoever, but I point out that it is a distinction without a difference. Consider the pole-vault competition in track & field. When the pole-vaulter clears a certain height without knocking off the horizontal bar, he or she has passed that height, a "test to compliance." The bar is then raised to a higher position, and the pole-vaulter attempts to clear the latter height. If he or she succeeds -- another "test to compliance" -- then the new height is the only level recorded for that vaulter for the event; if he or she fails, then the lower height is recorded for that vaulter the event. Is pole-vaulting a "test to compliance" event or a "test to failure" event?


To use the pole-vaulting analogy, it's my understanding (and I have a very limited understanding of this, so please forgive me), that the tire manufacturer sets a design target for a particular tire, and as long as it meets that criteria, they're happy. It could very well meet a higher criteria, but they don't necessarily test for that. In other words, they don't keep raising the bar to higher levels. If the tire clears the bar at the intended height, it clears the bar.

To make a hard example, take a tire, any tire. Say for example the Michelin Defender. Take a size, say 195/65R15 91T. Michelin has marketed this tire as a passenger all season tire. The tire is tested for compliance with the T speed rating and it passes. Michelin is happy, the tire is marked T, and it goes on sale.

The tire might pass the test for H. It might pass the test for V. But Michelin doesn't care. Michelin has H and V tires in this size and load rating. Michelin intends the Defender to be sold as a passenger all season tire, and not as a high performance tire, so it is labeled with a speed rating appropriate for the passenger all season tire niche, even though it may have the physical capability of more.

Again, that is my understanding. Anyone, please correct me if I am wrong. If my understanding is correct, that may be the root of CapriRacer's statement that it's more of a test of compliance, and not a test of failure. The tire isn't tested until it fails. It is simply tested to see that it performs at a certain level, and as long as it does, it is labeled and put to market.

Am I right or do I not understand it correctly?
 
Originally Posted By: Hokiefyd
The tire is tested for compliance with the T speed rating and it passes. Michelin is happy, the tire is marked T, and it goes on sale.

The tire might pass the test for H. It might pass the test for V. But Michelin doesn't care. Michelin has H and V tires in this size and load rating.

My understanding (which may be incorrect) is that in Europe, each vehicle is listed in a database as having a performance rating, and a tire retailer cannot fit a tire to that vehicle that has a speed rating that is less than the vehicle's performance rating. IF my understanding is correct, then there is a "penalty" (an exclusion of the market for certain vehicles) for a lower speed rating and thus an incentive to affix the highest achievable speed rating to every tire.

You will note that the NHTSA "Temperature" test procedure that I quoted above in message #28166816 contains the following language:

Quote:
(9) Reapply the load and without interruption or readjustment of inflation pressure, rotate the test wheel at 375 rpm for 30 minutes, and then at successively higher rates in 25 rpm increments, each for 30 minutes, until the tire has run at 575 rpm for 30 minutes, or to failure, whichever occurs first.

That language is suggestive of a procedure that allows a manufacturer to submit a prototype tire for testing without predetermining a suggested rating for the tire, and then to run the tire under test at successively higher rotation speeds (similar to a pole vaulter attempting successively higher settings of the cross-bar) until the tire fails, then accepting the highest speed that the tire passed as the rating that will be embossed on the sidewalls of production units of the tire.
 
Status
Not open for further replies.

Similar threads

R
New Tire Confusion
2
Replies
37
Views
1K
Pew
mclasser
Do longer tread life tires ride harsher over time?
2
Replies
27
Views
3K
FZ1
R
Tires & Tire Pressure for 2004 Mercury Grand Marquis
Replies
12
Views
530
Sequoiasoon
NormanBuntz
Some 2023 tire prices have become insane
2
Replies
29
Views
4K
andrew_j
C
Tire Reviews: Wide vs Narrow Winter Tires Tested
2 3 4
Replies
74
Views
4K
dumkid
Back
Top