Question by Calder.Net: Tire Rating vs. Tire Depth – Are we being misled by tire ratings?
When shopping for tires, I take note of the “rating” (eg. 100,000 km, 120,000 km etc.) which presumably tells me how far the tires can take me before they need to be replaced. (In the USA, I would see 50,000 mi. etc.)
Of course actual wear would vary depending upon weather, road conditions, tire rotations etc…but let’s pretend I drive in a perfect world which gives me maximum mileage for my tire dollar.
Mechanics recommended that I replace my tires when the tread depth is 5mm or less, and at 2mm it is too dangerous or even illegal to drive on them.
I was just at a tire store and a brand new tire’s tread depth seems to average between 9mm and 10mm.
When tire manufacturers rate their tires for a given mileage (eg. 100,000 km) do they mean that in a perfect world, if the tread began at 10mm, when my tires are at 2mm tread depth I should have been able to drive 100,000 km.?
But if I replace my tires at 5mm, then I really can get only 62,500 km out of them. Do I have all this right?
The first 3 answerers missed the point of the question..perhaps I should have been more succinct.
If I replace my tire when its depth is at 5mm, will I get significantly less mileage than its rating?
If I replace my tire when its depth is at 2mm, should I get the amount of mileage it is rated for?
Best answer:
Answer by who
Tak’m back and today most tires are glued together in the middle.Pirelli makes the best today…..by far.They got no seams in the middle.
Give your answer to this question below!
Please read other answers to this question at the very bottom of this page, below you will find a video and related articles that will try to answer the question, if you have a proper answer please post it at the bottom.
The staff at NissanVersa.org describes the function of the Tire Pressure Monitoring System, tire pressure, and tire rating.
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How to Choose the Best Tires for Your Vehicle
You probably have noticed the group of letters and numbers on the side of your tires before, but not all know what they stand for. They may seem a bit perplexing, however they’re actually quite easy to understand. In this case we will focus on one of the most bought tire sizes: P215/60R16 89S.
The First Letters
In this case the P is P-metric (you may want to remember it as Passenger) meaning that the tire is intended for use on regular vehicles. This can include Vans, SUVs, Light Trucks, and certainly regular cars.
You may also see the following:
T which is put on the spare – it means temporary.
LT is for Light Truck metric and is designed for tires on automobiles mean for carrying heavy cargo and trailers. SUVs and Trucks will often have these.
C stands for commercial and will typically be seen on delivery trucks and vans that are designed carry large loads.
ST which stands for Special Trailer and should only be used on utility, boat, or car trailers. They should not be used on regular cars or light trucks.
If the tire doesn’t contain a first letter it simply means the tire size is metric size and commonly found on cars from Europe.
To learn about what style or tire you should use consider visiting: What are the different types of tires
Second Place
This is the set of numbers following the first group of letters. It defines how wide the tire is from the widest portion of the outside sidewall to the widest portion of the interior sidewall. In this case the numbers stand for 215 millimeters (nearly 8.5 inches – just divide the number by 25.4 to find it in inches).
And in third…
After the first group of digits and a slash is a 2 digit value that is in place for the tire’s aspect ratio. This is the percentage of the tire’s sidewall height compared to the section height. In this case it is sixty which means the section height is around 5 inches. The bigger the value is the taller the sidewall is and the lower the number the smaller the sidewall will be.
Next Up
After the second set of numbers is a letter or two (R in this example). This is in place to define the tire’s internal construction. In this case it is R which means Radial. This will be seen on pretty much all cars. Another letter you may see is D which means the plies are diagonal. This will most commonly be found on spares and light trucks. If the letter is a B it means Belted and implies that the plies crisscross and are also reinforced with belts. This will not be seen on many cars these days.
Next Up
With the 2nd group of letters you can see a second letter, most usually Z, which stands for the tire’s speed rating.
The Final Lap
A lot of tires will also have a final collection of numbers and letters. These stand for the tire’s Service Description. They define the speed rating and load index. In this case the last three are 89S. This means that the tire has a load index of 89 and a speed rating of S. 89 equates to 1323 pounds (per tire). S means the tire is safe at speeds of up to 112 miles per hour.
I hope this has helped explain how tire ratings and sizes are defined. If you wish to learn more about tire sizes or what new or OEM tires can fit on your car check out Tire Info or if you plan to read about the ratings each individual tire has been given by the Government consider reading
The “right” set of tires greatly affects your vehicle’s performance and handling, road worthiness and safety, and fuel economy. Here is the spin on how to choose the right tires for your vehicle.
There are so many brands available in the market today and they all claim to be the best performance-boosting-safety-enhancing-fuel-efficient-super-tires. Well, maybe they really are but how would you choose the right one for your vehicle?
It all depends on the type of vehicle you drive, the climate and terrain of your locality and how you intend to use your vehicle. After considering these factors, your decision should be based on the tire’s performance and safety, price, brand and appearance.
To help you weigh your options, here are a few basic tire classifications to start with:
TIRE DIAMETER and WIDTH
Each vehicle model has a specific range of appropriate tire sizes. This is usually listed in the owner’s manual or on a label posted on the vehicle. Anyway, it’s easy to get this information online.
TIRE TYPE
There are three basic tire types: radial, bias-ply and bias belted. Most vehicles today come equipped with radial tires because they generally offer better performance and more durability.
Of course, you don’t need to know that some tires specify in their labels that they are for use as temporary spares, for passenger cars or for light trucks. But now you also know.
TREAD DESIGN
Tread, here, refers to the rubber on the circumference of the tire which is designed to make contact with the ground.
The most common are all-season tires which can be used for regular highway conditions, rain, snow, slush and mud. This type of tire usually has an “m + s” (mud + snow) label. Then there are also specialized treads for snow or for regular highway conditions only.
All tires made by manufacturers who distribute to the US (most likely those also available in your area) must meet federal safety standards. Grades are assigned by manufacturers after performing tests designed by the government.
Except for off road tires and temporary spares, each tire has a label printed on paper or molded on the side of the tire. The quality ratings are based on the tire’s tread wear, traction and temperature resistance.
Tread wear grade
This tells you how long the manufacturer expects the tire to last in comparison to other tires if all were subjected to the same usage conditions. For example, a tire rated 200 is expected to last twice as long as a tire rated 100.
Traction rating
This is scored A, B or C, tells you how well the tires can stop your vehicle on wet roads. Those tires rated “A” offer the best traction.
Temperature resistance
This rating, also scored A, B, or C, measures how well the tire will resist overheating during sustained high speed use. Yes, a tire graded “A” represents the best performance.
MAKING SENSE OF LABELS
Here’s how a typical tire label looks like: P205/60R-16 91V
In this tire label, “P” indicates that the tire is for passenger cars. Variations are “LT” for light truck or “T” for temporary or spare tire.
“205/60″ means that the tire is 205mm wide and its side walls are 60mm tall.
“R” in this case means that this is a Radial tire.
“16″ refers to the diameter of the wheel rim which is 14 inches.
“91″ is the tire’s load index.
And the last letter “V” refers to the speed rating, the maximum safe speed that the tire can still be performing under ideal conditions. Variations are: Q (99mph), S (112mph), T (118mph), U (124mph), H (130mph), V (up to 149mph), Z (more than 149mph), W (168mph), and Y (186mph).
by: Evert Don Canada
AutoTerminal.com – A worldwide distribution network selling used Japanese vehicles. Region-based distribution centers are located in New Zealand, Australia, United Kingdom, USA, Asia, Africa, and South America.
Article from articlesbase.com
More Tire Rating Articles
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you are correct – this rating assumes perfect air pressure all the time and light driving useage – so that they can milk every mile out of them – chances are , you will come close but not match the mileage
First of all the tire ratings are all due to varying factors such as- performance tires are softer and wear out quicker not to meantion the way they are used. Touring tires are rated higher mileage because of the rubber compound is harder, therefor last longer, and even those vary. The difference of the 9mm & 10mm really has nothing to do with the mileage rating. This can simply be due to the difference in the manufacturure. replacing them at 5mm seems to soon, you can go down a little more before replacing them. Tires will definitely last longer when regularly aired up and rotated about every other oil change. I always get at least the rated mileage or more.
Tire manufacturer wear warranties are based on a tire worn down to the wear bars (about 2mm or 2/32-inch). In most countries and states this is the legal minumum tread depth. Properly maintained any tire should be able to easily make this warranty, so that if the tire has a 100,000km/60,000 mile treadwear warranty it should have that much use on it when it gets to the wear bars.
For best performance most in the industry recommend replacing tires before they are worn to this point for safety reasons. The traction a tire provides in wet or winter weather drops off dramatically below about 5mm or 4/32-inch remaining tread depth. http://www.tirerack.com has some interesting results on their web page testing identical cars with identical tires at full new tread depth, 4/32-inch and 2/32-inch. It is frightening how much longer it takes the worn tires to stop on wet pavement! Several tire manufacturers, notably Continental are lobbying to have legal standards changed to a 4/32-inch minimum tread for safety reasons based in part on those tests. So far only Michelin is opposed – for environmental reasons.
Replacing tires before they reach the legal/warranty minimum tread depth of course means that you would be replacing the tires before they have reached their maximum use. But it is in those last few mm of tread that a tire provides the least traction in poor weather.