I got new rear tires.

Treadwear Ratings

Ok please correct me if I am wrong, a lower number usually means a softer tire. In exact terms a treadwear rating refers to the rate at which a tire wears out. It is not a measure if the actual hardness or softness of the rubber. Now my question is, if you have a 245 tire with a treadwear of say 220 would a tire of the same compound actually have a lower number if it was a narrower tire. My guessing is that a smaller tire with a smaller contact patch would wear out faster than a larger tire if made from the same compound tire. Does anyone follow my logic on this? More rubber on the road under the exact same conditions should last longer due simply to the amount of rubber it would take to wear it down.



Now we get to the root of my question. My current tires on the rear of my car are 245/50/16 with a 220 treadwear rating. I managed to eat them up in 6 months of street driving with zero track use. The new tires I just bought and have yet to take down to the tire store are 225/50/16 with a treadwear rating of 420. They are both Traction A, Temp A rated. It kinda worries me that they are both a narrower tire and have a higher treadwear rating. I was prepared for a loss of traction due to the smaller size of the tire and effective gear ratio change. However now I am really worried after seeing my current numbers vs the numbers on the new tires. The only good thing about the whole situation is my transaxles might last a bit longer and I won’t break as many mounts. (3 Isuzu’s in 2 years and engine is now held in by 2 solid mounts, 1 poly mount and 2 stock trans mounts, which will be upgraded to Rodney Dickmans poly trans mounts.





So anyone want to chime in with input regarding traction vs treadwear vs tire size?

 :The Install and Impressions both mine and Tom:

Well I went down to my fav tire shop. "Tom The Tire Guy" which is a privately owned and operated single tire store. Not a big chain store. I showed him the tires and he looked at my old bald 245's on the back that he had sold me last spring, he kinda shook his head that I ate them up that quick. He checked the tires over that I brought in and showed me the DOT number on them to make sure they were not some of the junk re manufactured tires that are being sold around here. He checked the ratings on the tires and told me they are very similar to some Yokohama tires he gets for customers. The end result of it, he said they are a really decent tire. They should probably do my car fine.He ended up doing the mounting and balancing on the house, which was really nice. I guess being a long time customer he still tries to take care of car guys.

So I got them on the car, and left. The snow was starting to thin and the ground was only wet. (yes it snowed this morning) First thing I noticed is the sidewall is much firmer with these tires. The back end felt more planted. I did a rolling start in 2nd and punched it, with my old tires the back end would have been all over the place in the rain, however they seemed to hunch down had a bit of controllable wheel spin and then grabbed and took off. I am very impressed. For the record they are "Fierce" brand 225/50/ZR16's I posted a pic of the tread pattern when I first got them. I will see if I can find the pic and repost it.

Thank You everybody that posted info about the treadwear stuff. He confirmed what you all said. The treadware is only a guidline and is not even close to an exact spec for a tire. Every brand seems to have a diffrent way of justifying what they feel is the rating and it can vary widly. I guess it is kinda like jeans. A 34 waist Levi won't be the same as a 34 waist Wrangler. Best to try it out and see how it fits.

Edit to add pics