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Tornado 24th September 2016 12:12 AM

Tyre Comparison Tools : Ply Composition, E-Markings, EU Label, UTQG
 
5 Attachment(s)
Guys, recently I was in market for tyre replacement of my cars.
I started researching, on the basis of user reviews on Internet. I found that many user reviews are conflicting each other due to subjective definitions of ride quality , handling, comfort, hard cornering, wet grip. All these properties of tyres also differ as per road conditions, driving style, vehicle type & characteristics.

Hence tried to find out science based methods to judge & compare tyres qualitatively & quantitatively. I found
1)Tyre Ply Composition
2) Tyre Ply ratings
3) E or e markings.
4) European label
5)UTQG ratings.

1)Tyre Ply Composition. :
Attachment 209631 Attachment 209630Attachment 209639
We can see tyre ply composition mentioned on the sidewall of the tire.
Functions of the ply :
To provide impact resistance / resistance to the burst.
To provide ride quality comfort.
To provide handling comfort.

Different ply composition are meant to provide a sweet ballence between ride comfort & impact resistance & handling comfort. There are two places where these plies are located.
1)Tread plies : located throughout underneath the tread rubber.
2) sidewall. ; located underneath the rubber of the sidewall.

Tread plies :
These are the textile & or metal materials used in composition of tyre as a casing/ foundation for the tread blocks/ buttons.
In old days, only cotton plies were used later replaced by Rayon. Rayon too got replaced by Nylon, Polyamide, polyester etc.
At the base of the textile materials, there are steel plies/belts . Steel plies imparts impact resistance to the tyre.
More is the number of the steel plies better is the resistance to the burst.
In India, most of the car tyres have either 1 ply or 2 plies of steel. However using only steel plies would make the ride quality as if car is running only on steel rims wrapped in rubber cover.
Among the present day textile plies nylon has got best tensile strength. Nylon imparts impact resistance to the tyre. Most of the car tyres have 1 or 2 nylon plies under the tread. Again more is the number of nylon plies more is the tyre resistant to the burst.
But since nylon is hard material. Using nylon alone makes the ride comfort quality hard too. Hard ride comfort quality means our buttock & back joints get the thrust & pain whenever car passes over road irregularities.
Also nylon has got tendency to retain it's shape. This tenancy to retain the shape is decreased only when it's temperature is increased considerably.
That means when the car is parked & tyres are cold. Shape of the contact patch (where tyres are touching the ground) is flat & rest of the tyre is round. The flat part of such tyres of the parked car is called as flat spot. When car moves & tyres start rolling, ride comfort quality feels disturbed whenever the flat spots come in the contact of ground. It takes 2 to 3 km distance atleast to get the tyre temperature to rise enough so that the tyre shape becomes fully round again.

Those whose daily drives are just 2 to 3 kms episodes with a rest of 2 to 3 hours in between feel this discomfort due to flat spotting.

To overcome these disadvantages of hard ride quality & flat spotting discomfort,
tyre makers tried to soften the nylon with special chemical treatment without hampering the tensile strength (impact resistance). And got a material called Polyamide. To conclude, the tyres with polyamide plies are more comfortable than nylon.

Polyester : Polyester has little lesser tensile strength than nylon /polyamide but has more of a spring like shock absorbing property. It gets deflected easily as compared to nylon /polyamide due to road irregularities and provide shock absorption better than nylon /polyamide. It also provides impact resistance but little lesser than what nylon polyamide provides.
Most of the tyres have 1 or 2 polyester plies under the tread rubber.

]Sidewall plies : These are plies located underneath the rubber of the tyre sidewall. Mostly they are made up of polyester. Mostly car tyres have 1 or 2 polyester plies in their sidewalls. Lesser is the number of the polyester plies in the sidewall of the tire higher are the chances of sidewall bulge /cut.

Nylon is used as a ply in the sidewalls of the truck /moped tyres only. As it would hamper the shock absorption (ride comfort & handling too in case of cars.

The name of the ply is also prefixed by a number which tells us number of plies used in the tyre tread & the sidewall.



2) Ply ratings :( this system is now obsolete)
Ply rating use to tell us how many times the modern plies are impact resistant as compared to the old day cotton plies.
For eg. Ply rating of 8 means the particular tyres plies are 8 times stronger than the cotton ply.

3 ) E markings.: (Accepted by European union, United nations) ECE /UNECE markings :
Of late, since, 2012 onwards, United nations have passed some regulations so that customers can judge the safety & Eco friendliness of the tyres.
For getting these UN markings on the tyre, tyre manufacturer needs to apply in a member country of UN (Countries who have pledged for safety & anti pollution).
Attachment 209636
1) Marking is given as a 'encircled' capital 'E' or small 'e'letter on the sidewall.

2)Letter E is suffixed by a number code, eg 2,1,4.. etc. This number is the codename of the country in which tyre maker of the particular model applied & registered for passing through the safety & environment criteria.
Attachment 209637
For eg.
E4 means Netherlands
E1 means France.
E 45 means Australia.
e 13 means Luxembourg.
I am posting a pic of the screen shot of the country code names. Attachment 209632
Attachment 209638
Near the encircled E, you can see few numbers & letters. These numbers suggest the number of the law amendments & application number of the tyre maker.

3)After these number codes, you can see letters 'S' & 'W' & sometimes' R'

'S' means tyre has passed the Sound (Tyre noise) test conducted in Europe. European laws are least tolerant to the noise, The letter S is suffixed by a single digit number eg 1, 2.
Number '2' suggests that Sound criteria is fulfilled according to second amendment(as of now, latest).

Letter 'W' suggests suggests that the tyre passes through Wet grip safety test. The letter W is also suffixed by a number. This number again points towards number of the amendment in the law. As of now number '2' suggests latest amendment.

After the letter 'W' you can see letter 'R'. I don't know exact meaning of this, but probably it might be Rolling resistance( less is the rolling resistance, more is the fuel economy.
Mefeels, these are important markings which suggests tyres are full filling minimum criteria.

I found there are few scientific methods accepted by various governments in the world to create competition amongst the tyre manufacturers to improve quality of the tyres apart from minimum expectations found on the E markings and help buyer to choose a good tyre.

These are
1) European (EU) label (Accepted & compulsory by European Union & UN laws )
2) UTQG. (Accepted & compulsory by US laws)
3)Japanese label
4)Korean label
I will narrate about EU label & UTQG systems here as I haven't found any useful info or difference in Indian context about later too, however they( Korean & Japs) follow same (EU label) fuel efficiency (Rolling Resistance) & Wet grip tests. though labels look different. And they have excluded noise test or ratings.It seems they are not worried about the noise pollution

The European Label: shows & include following things
Attachment 209633
Attachment 209634

1)Fuel efficiency calculated on the basis of rolling resistance.
2)Wet grip.
3)Noise
Wet grip & noise tests are essentially same as carried out under of E markings. The difference between E markings & EU label is that former is qualitative(indicates that tyre fulfills minimum criteria) while later is qualitative as well as quantitative.
Since 1st November, 2012 all tyres made after 1st July, 2012 must show the European Tyre Label.

Symbols used on label
The tyres are classified in terms of three performance characteristics:
• Fuel Efficiency (letters A to G)
• Wet Grip (letters A to G)
• External Noise ( symbol of sound waves is used also there is numerical mention of actual sound generated in terms of Db.
More information: Energy topics - European Commission

Fuel Efficiency:
The classification in terms of fuel efficiency is divided into seven classes, from the A-class (the highest) to G-class (the lowest). A tyre in the A-class consumes 0.5 litres less at 100km than a tyre in the G-class. An essential component for fuel efficiency is the rolling resistance or rolling friction.

Rolling Resistance :
Rolling resistance is the force that opposes motion. It is formed, for example, when a wheel is rolling.
Getting class/rating A means best fuel efficiency.

Average :Average value is between C-E. Class D is not used.( because letter D was assigned to some other code long before EU label was introduced.)

F is worst.

Wet grip
It shows how efficient the vehicle can brake on wet roads. Wet grip is an important feature especially with summer tyres. Class A has the highest safety and the shortest braking distances. Class F has low security and the longest braking distance.

The wet grip classes are based on test driving on wet asphalted road with a speed of approximately 80 km/h. The difference between the braking distance of the tyres is 1 to 1,5 metre per grade. E.g., the difference in braking distance between Class A and Class F are up to 18 metres.

Average: The average value of the tyres is between class B-E.
Class D and G doesn't exist.

Tyre Noise
The symbol indicates the external rolling noise in decibels and as a 3 class sound wave symbol to clarify whether the tire can keep the recommended level. External rolling noise does not correspond to tyre noise inside the compartment.
The test is carried out on actually running car with microphones placed near the windshields after confirming that other environmental & human factors does not hamper with the test results

A continuous sound level above 80 decibel can cause health problems.

Symbol used :
Three sound waves symbolize the worst results. These are the tyres that exceed the maximum limit of approval. A symbol of 2 sound waves have noise level that corresponds with the approved sound level. Tyres that are marked with 1 sound wave are over three decibel quieter than the approval
Following are the noise limits approved by EU, expressed in decibels for widths of tyres.
72 db for 145mm & bellow
73 db for 145 to 165 mm
74 db for 165 to 185mm
75 db for 185 to 215 mm
76 db for over 215 mm

All these tests are carried out in government approved labs & printing wrong info on the label is punishable by law. It is compulsory for the tyre seller to display the label on the tyre before selling it.

UTQG (Uniform Tire Quality Grading.:To be continued in next post.

Tornado 24th September 2016 12:32 AM

Re: Tyre Comparison Tools : Ply Composition, E markings,EU Label,UTQG.
 
1 Attachment(s)
Uniform Tire Quality Grade (UTQG) :Attachment 209640
The U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration's (NHTSA) Uniform Tire Quality Grade Standards (UTQG) were originated to provide consumers with useful information to help them purchase tires based on their relative treadwear, traction and temperature capabilities. While it is required by law for most passenger car tires sold in the United States, it is not required for deep treaded light truck tires, winter/snow tires, temporary spare tires, trailer tires, tires under 12" in diameter and other select tires.
When looking at UTQG ratings it is important to realize that the Department of Transportation does not conduct the tests. The grades are assigned by the tire manufacturers based on their test results or those conducted by an independent testing company they have hired. The NHTSA has the right to inspect the tire manufacturer's data and can fine them if inconsistencies are found. While most new tire lines have their grades established when they are introduced, they are allowed a 6-month grace period to allow the tire manufacturer to test actual production tires. Once a grade is assigned it must be branded on the tire's upper sidewall and printed on its label. While the Treadwear Grade was originally intended to be assigned purely scientifically, it has also become a marketing tool used by manufacturers to help position and promote their tires.
"Maybe it's because tires are so complex and their uses can be so varied, that [UTQG] grades don't always reflect their actual performance in real world use."However they are helpful in comparing one tyre with the other.


Treadwear Grades
UTQG Treadwear Grades are based on actual road use in which the test tire is run in a vehicle convoy along with standardized Course Monitoring Tires. The vehicle repeatedly runs a prescribed test loop in West Texas for a total of approx 12000km. The vehicle can have its alignment set, air pressure checked and tires rotated as per rules.
The test tire's and the Monitoring Tire's wear are measured during and at the conclusion of the test. The tire manufacturers then assign a Treadwear Grade based on the observed wear rates. The Course Monitoring Tire is assigned a grade and the test tire receives a grade indicating its relative treadwear. A grade of 100 would indicate that the tire tread would last as long as the test tire 12000km , 200 would indicate the tread would last twice as long(24000km), 300 would indicate three times as long(36000km) , etc.
Lasting tread doesn't mean getting bald.It means the treadwear is such that safety has started deteriorating.
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 12000 km. 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.

Traction Grades:
UTQG Traction Grades are based on the tire's straight line wet coefficient of traction as the tire skids across the specified test surfaces. The UTQG traction test does not evaluate dry braking, dry cornering, wet cornering, or high speed hydroplaning resistance.
The Traction Grade is determined by installing properly inflated test tires on the instrumented axle of a "skid trailer." The skid trailer is pulled behind a truck at a constant 65 kmph over wet asphalt and wet concrete test surfaces. Its brakes are momentarily locked and the axle sensors measure the tire's coefficient of friction (braking g forces) as it slides. Since this test evaluates a sliding tire at a constant 65 kmph, it places more emphasis on the tire's tread compound and less emphasis on its tread design.
In 1997, the UTQG Traction Grades were revised to provide a new category of AA for the highest performing tires in addition to the earlier A, B and C grades. Previously the A grade had been the highest available.
Today the grades are as follows:

Traction.
AA ( Best Traction)
A
B
C (least but acceptable)

Sometimes we get to see AA rating (best) for a tyre under UTQG system while on EU label it is B on the EU label system for the same tyre rather than expected A !! . This conflict can be due to three reasons.
1)Difference in speeds at which wet grip test is carried out in these two systems. ( 65 kmph vs 80 kmph)

2)Also the UTQG Wet grip (Traction) test is carried out on a tyre mounted on a axle run by a trailer pulled by a truck while EU label Wet Grip test is carried out on both the tyre mounted on axle & run by a trailer as well as tyres mounted on actual car.

3) The UTQG Traction test is carried out on Asphalted as well as concrete road. And EU label Wet Grip test is carried out only on asphalted road.

So mefeels, EU label is more useful for those who do higher speeds & use both concrete & asphalted roads.

Temperature (Resistance) Grades:
The UTQG Temperature Grade indicates the extent to which heat is generated and/or dissipated by a tire. If the tire is unable to dissipate the heat effectively or if the tire is unable to resist the destructive effects of heat buildup, its ability to run at high speeds is reduced. The grade is established by measuring a loaded tire's ability to operate at high speeds without failure by running an inflated test tire against a large diameter high-speed laboratory test wheel for half an hour.

TemperatureGrades :
A: Over 185 kmph
B: Between 160 to 185 kmph
C: Between 135 to 160 kmph

Every tyre sold in the United States must be capable of earning a "C" rating atleast which indicates the ability to withstand 135 kmph speeds. While there are numerous detail differences, this laboratory test is similar in nature to those used to confirm a tire's speed ratings.

]PS :
Above mentioned ratings / labels may not be suitable to find a best tyre but are definitely helpful for comparing them.

Irespective of how best is the rating of label it is important to see the manufacturing date code. Rubber deteriorates due to aging & storage.

In case of all the above ratings, labels, markings, you can find a lot of difference as soon as you change size, speed index , load index, suffix, prefix.
It is equally important to read /discuss user reviews before taking final plunge.
Bricks & bats welcome, please feel free to correct if you find anything wrong in the opening posts

bhvm 24th September 2016 10:00 AM

Re: Tyre Comparison Tools : Ply Composition, E markings,EU Label,UTQG.
 
Thank for creating This thread Tornado,
May I request it may be set as a sticky guide by the Mods.

Here is Tyre Speed information-
[code]
Quote:

Code mph km/h Code mph km/h
A1 3 5 L 75 120
A2 6 10 M 81 130
A3 9 15 N 87 140
A4 12 20 P 94 150
A5 16 25 Q 100 160
A6 19 30 R 106 170
A7 22 35 S 112 180
A8 25 40 T 118 190
B 31 50 U 124 200
C 37 60 H 130 210
D 40 65 V 149 240
E 43 70 Z over 149 over 240
F 50 80 W 168 270
G 56 90 (W) over 168 over 270
J 62 100 Y 186 300
K 68 110 (Y) over 186 over 300

Metric to Imperial tire conversion chart[edit]
Quote:

R15

215/75/15 27.7"x 8.5"

225/70/15 27.4"x 8.9"

225/75/15 28.3"x 8.9"

235/75/15 29.0"x 9.3"

245/75/15 29.5"x 9.6"

255/75/15 30.0"x 10.0"

265/70/17 30.6"x 10.

205/85/16 29.7"x 8.1"

215/75/16 28.7"x 8.5"

225/70/16 28.4"x 8.9"

225/75/16 29.2"x 8.9"

235/70/16 29.0"x 9.3"

235/85/16 31.7"x 9.3"

245/70/16 29.5"x 9.6"

245/75/16 30.5"x 9.6"
Tyre Weight/ Loading Charts-

Quote:

Load Index Pounds Kilograms
Load Index Pounds Kilograms
71 761 345 91 1356 615
72 783 355 92 1389 630
73 805 365 93 1433 650
74 827 375 94 1477 670
75 853 387 95 1521 690
76 882 400 96 1565 710
77 908 412 97 1609 730
78 937 425 98 1653 750
79 963 437 99 1709 775
80 992 450 100 1764 800
81 1019 462 101 1819 825
82 1047 475 102 1874 850
83 1074 487 103 1929 875
84 1102 500 104 1984 900
85 1135 515 105 2039 925
86 1168 530 106 2094 950
87 1201 545 107 2149 975
88 1235 560 108 2205 1000
89 1279 580 109 2271 1030
90 1323 600 110 2337 1060

[/code]
Credits-
https://en.wikipedia.org/wiki/Tire_code

Tyre Speed Rating - Ratings Explained | Blackcircles.com

Tire Tech Information - How to Read Speed Rating, Load Index & Service Descriptions

P.s- The Formatting is gettting messed up.
Mods please help.

Tornado 25th September 2016 12:14 AM

Re: Tyre Comparison Tools : Ply Composition, E-Markings, EU Label, UTQG
 
4 Attachment(s)
The tyre sellers have habit of showing the tread of tyre models available with them rather than the sidewall & ask the customer to choose one which he likes!!

However, there are few physics facts found while looking at the tread pattern of the tyre which can help us comparing characteristics of various tyre models before using the tools mentioned in the opening post.

1) More the number of tread buttons, less is the noise. To get more numbers of tread buttons tyre need to have maximum number of circumferential grooves & these circumferential grooves need to be criss-cross by horizontal or oblique grooves.

2)More the discrepancy in the size of tread buttons, less is the noise.

3)More the discrepancy in the size of tread buttons better is the hardcornering experience.

In summary, above mentioned properties are found in asymmetrical tyres. Hence asymmetrical tyres are less noisy and are better for hard cornering too as compared to symmetrical tyres.
Attachment 209657
Attachment 209658
Both the tyres shown above are asymmetrical but former has more grooves, deeper grooves more number of buttons,

3) Deeper the grooves in the tread , better are the wet handling & resistance to the aqua planning & vice versa.
Deep grooves help more water to be channelled & expelled from the area between contact patch & the road underneath as compared to shallow groves.

4) More the number of uninterrupted grooves (across the tyre circumference & or across the width of the tyres ) ,better is the wet grip & resistance to aqua planning.& vice versa.
Here is image of uninterrupted grooves.
Attachment 209659
Tyres which have more number of uninterrupted grooves, hence, are best for wet handling. Tyres with interrupted grooves are better for wet grip but not best.

Straight line interruption in the grooves leads to formation of angles where water flow gets " bottle necked" or clogged leading to lifting up the tyre away from the road surface in upward direction leading to mild aqua planning as compared to those without angles

Among the directional tyres with interuppted groves, interruptions which form curves are better for water expulsion hence better wet handling as compared to interuptions which forms angles. See the pic of interrupted grooves of a directional tyres. Attachment 209660

In summary all above mentioned properties (No.3,4)are found in directional tyres, hence directional tyres are better wet handlers as compared to non directional tyres.

5) Directional +symmetrical tyres have tread buttons with equal sizes hence noisy.
Absence of intruptutions in the grooves leads to formation of lesser number of tread buttons as compared to tyres which have intruptutions. Hence directional tyres with intruptutions in their grooves are noisier than those with uninterrupted grooves.

In summary :

6) 'Symmetrical + non directional tyres' (most frequently found as OE in India) are union of all trades (silence , hard cornering, wet grip.
grip) but jack of none.

On the other hand, 'directional + asymmetrical tyres' would be union of all trades & jack of all trades.However I have not came across such a tyre. They would be fun to do hardcornering on wet roads.

Summary of Tyre properties of basic tread patterns, one as compared to remaining :

Symmetrical +Directional tyres : Better wet grip.

Asymmetrical tyres +non directional : Better hard cornering.

In other words,
Tread pattern, most prone for aquaplaning (worst wet grip) are non directional +symmetrical.

Tread pattern, most noisy would be directional +symmetrical.

PS : Someone please research and mention which basic tread pattern would be worst for hard cornering, symmetrical or directional? Logically speaking, if asymmetrical are best for hard cornering symmetrical should be poor or worst?

[If above mentioned facts are confusing you, better to follow the EU LABEL, UTQG, E MARKINGS.

bhvm 25th September 2016 09:42 AM

Re: Tyre Comparison Tools : Ply Composition, E-Markings, EU Label, UTQG
 
Manufacturers have grouped the Tread patterns Roughly in these groups-

H/T - means Highway Terrain. This tire is made for paved roads. Most SUVs come originally equipped with H/T tires are they are usually quiet, comfortable and long lasting. Perfect for daily urban driving. 99% SUVs & Cars in India come with HTs. They're the bread and butter tyre. All rounders.

A/T – means All Terrain tire. The tire is designed to handle both off and on road driving. The tread design is more rugged compared to the H/T that is why it is favored by SUV owners who are going after the looks. Sidewalls are stiffer, More resistant to abuse. There is a slight increase in road noise & Stiffness when going from HT to AT.

M/T – means Mud Terrain. This is the ultimate “macho” tire as evident with its aggressive tread design. The tire is good for mostly unpaved roads. Think traversing farms and conquering mountains. The tire is uncomfortable and noisy for daily commute in paved roads though, so make sure you need this before changing over.

What do these symbols mean in your SUV tire? – H/T A/T M/T | Yokohama

HP- A new breed of "Crossover" tyres. Some examples are Goodyear Wrangler HP & Michellin HP. These are usually for the Crossover "Urban SUV". They're designed to carry heavy kerb Weight of SUV & Luggage in Comfort on road, without the harshness or Noise of usual AT tyres. HP are what i call High speed SUV tyres.

M & S- Usually the elder brothers of MT. More aggressive, open Tread pattern. Optimized for Mud & Sand. These also have very tough sidewalls as they're optimized to run at lower air pressures (10~15 PSI). Lower Air pressure helps in sand.

Snow Tyres- Looks like HT tyres but is made from softer Rubber compound that grips well on delicate snow. Not much famous in India.

Racing Slicks- Smooth, No tread tyre for Racing. These will not work anywhere except smooth, Dry Race tracks. Made of very soft, Sticky Rubber compound. Highest Grip, least life.

Great reads-
Tires 101 on Different Styles of Tires :: Souza's Tire Service

https://www.kaltire.com/whats-the-di...terrain-tires/

Tornado 25th September 2016 04:45 PM

Re: Tyre Comparison Tools : Ply Composition, E-Markings, EU Label, UTQG
 
Well the UTQG & EU label, E marking tests doesn't apply to Mud snow, winter tyres.

Tornado 6th October 2016 07:20 PM

Re: Tyre Comparison Tools : Ply Composition, E-Markings, EU Label, UTQG
 
Of late, I replaced 205/55R16 tyres of one of my car taking above mentioned factors.

http://www.theautomotiveindia.com/fo...-alnac-4g.html

bharathbigb 9th October 2016 09:03 PM

Re: Tyre Comparison Tools : Ply Composition, E-Markings, EU Label, UTQG
 
So,Can someone suggest me the best set of 165/65/R13 ? :)

Tornado 9th October 2016 09:18 PM

Re: Tyre Comparison Tools : Ply Composition, E-Markings, EU Label, UTQG
 
Quote:

Originally Posted by bharathbigb (Post 515902)
So,Can someone suggest me the best set of 165/65/R13 ? :)

It's possible to suggest you a good tyre if you visit tyre shops & post the UTQG ratings, E markings, ply composition of few renowned brands in your size.


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