What does 'treadwear' means.?
 

Dear Friends,i noticed our Bridgestone has a Treadwear of 140,what does this means,some people told me,the lower the treadwear the better the grip,while some people tell me it is about lifespan....thanks.

he treadwear rating of a tire is a reflection of the expected lifespan of the tire. The higher the treadwear rating, the longer the tire should last.

This rating is based on comparison with a "Course Monitoring Tire" (CMT)with an assigned treadwear of "100." A tire with 300 treadwear should last three times longer than the CMT.

However, most manufacturers use this rating as a marketing technique. This means that many treadwear numbers are stated higher than "actual" to give an advantage over a competing tire/brand. Treadwear numbers, however, can usually be reliable when comparing different tire offerings from the same manufacturer.

Tire manufacturers are subject to spot checking of tires and their tire ratings, so they need to be careful in overstating their treadwear rating. Aka if they claim a 300 and are really a 200 they would be in trouble, but the same designation doesn't go the other way.

A tire could actually be a 300, but they may use 140 for marketing purposes, capitalizing on the fact that people think the lower the number the grippier the tire, as was posted in your original question.

It's really a bad system, and not one that will correctly give you a whole lot of exacting info on how good a performance tire is, nor how long the tire will last.

My last set of 300 rated tires were toast in less than 10k miles (6 months).. due to my large right foot.. so if you're driving hard (not talking burnouts, just driving a car hard will wear tires significantly in the rear) you're going to blow through tires..

Both. Grippier and quicker to wear out.

One person posting on tirerack said that as a very general rule of thumb, ASSuming you're a typical daily driver, have good roads, etc etc ... then, if you multiply the number by 72 you'll have a very rough approximation of the life of the tire under optimal conditions.

So 140 x 72 means you'll be replacing these OEM treads at roughly 10K miles, give or take a couple thousand.

Also -- since our tires don't rotate, it's much more important to have good alignment and balance.

Where does this 72 come from?

I suspect there might be nominal science behind it, but let's just say they pulled it out of their (cough) ear. :)

Because we had a set of Michelin Pilot Sport A/S last nearly 2x as long as this guesstimate would indicate. However, that was on a road cruiser (Acura 3G TL) doing 80% highway driving, and the tires rotated every 5K ... we got rid of the tires to go to RE960 A/S Pole Positions, which were an immense improvement in road handling.

The tire non-rotation has me concerned on the Z, almost to the point I deselected it. 18" rims (base) have more options and are are more economical than what tirerack was showing for 19" (sport) rims. So I'm pretty well set on F1 Eagle A/S -- unless either Bridgestone RE960 or Michelin Pilot Sport A/S Plus tires get offered in our sizes by tirerack.

Tire Tech Information - Uniform Tire Quality Grade (UTQG) Standards

The "treadwear grades" section might help... :tup: