tifosiman

This may be a dumb question.................but............

My old set of RA-1's was looking rather ragged and needed to be replaced, so I picked up another set this week and had them mounted and balanced. The tread and everything looks exactly the same as my old set (wll, now that there is tread where there was none ), but the treadwear ratings are different. The old ones were 40, the new ones are 100. Was there an actual compound change, or a change in the way they rate the tires? Or, are there two different compounds available and I just never knew that?

Thanks in advance!

mitch236

Why is there a cone in the middle of the track? (your avitar)

tifosiman

That pic was taken at a rather interesting auto-x course in Cincinnati. The cone is one side (left) of a gate that the cars had to run thru in an attempt to make that corner more of a decreasing radius corner than it really was.

Z-man

tifosiman:
Tire construction varies from year to year, even with the same brand and model. In order to keep up with development and the competition, tire companies will switch compounds, construction methods, even tread patterns to have the tire that 'everyone wants.'

However, they won't change the name too often because if they have a good tire to begin with (like the Toyo Proxes RA-1's), they want to build their customer base. Racer X had great experience with Model Y tire, and he wants another model Y tire, so the company keeps the name.

It's mostly a marketing thing!
-Z.

PS: This season, I switched over to the RA-1's, and love them so far, both on the track and at autox!

Brian Morris

My guess is that they just "corrected" the rating on that tire. 40 seems out of whack and 100 seems more in the right ballpark. For comparison -

Hoosiers - 40
Kumhos - 50
Yoks - 60
MPSC - 80

Z-man - were you using Kumhos before? If so how do the RA-1s compare?

--Brian Morris
89 951

Z-man

Nope: I was using the Pirelli P-Zero C's. Nice tire, very durable, but they didn't offer as much grip as I perceive the RA-1's to have. However, that said, I only have 1 DE event (3 days at Mid-Ohio) and 1 autocross on the RA-1's so far. I'll report back on my feelings about the RA-1's as the season progresses.

-Zoltan.

George A

Z-man,

That's interesting. My perception is that the PZero C's stick better than the RA-1's. I think the RA-1’s and C’s are extremely similar, but I give the nod to the C’s for grip and sidewall stiffness. I just found another set for the rear of my car and am happy as can be. I love the C's, I wish they still made them. I've got four fronts and three rears, that should last me for a while. I haven't tried the Corsa's yet, but am hoping that they are similar. I use them as my street tires and run them occasionally on the track when I'm too lazy to put on the slicks.

George

Z-man

George: one of the reasons I switched to the Toyos is because the P-Zero C's are no longer available, and the Pirelli P-Zero Corsa's aren't available in the 16" diameter size.

That said, I would agree with you that the two tires are very similar in terms of wear and grip. I just think the RA-1's have the edge in the grip department: but that's just my perception of the tire so far...

Interesting thread,
-Z-man.

forklift

I like the use of "perception" by Z-Man here. I can only compare to 0-32s, but my perception of the RA-1s full tread vs. the 0-32s is that although the 0-32s may have slightly better grip in cornering, or probably about the same, the breakaway characteristics of the Toyos are MUCH better. This inspires confidence, and hence better lap times. Under braking the full tread 0-32s were much better with no squirm, but as my RA-1s are wearing down, I am getting less and less of that. The 0-32s were noisy as hell also. I am surprised the 0-32s have a lower tread rating as they seemed to wear better than the Toyos.

Brian P

I thought I heard that the tread rating is only consistent within a company - i.e., different manufacturers have different ideas of what constitutes an 80 tread rating.

tifosiman

Well, this is an interesting thread. Thanks for the responses. I guess I will just drive on them and see what my perception of them is. But even then that may be a bad comparison (ie. new verses almost worn out). My hope is that I don't perceive them to be less grippy than the old ones with the 40 rating. If I perceive them to be more slippy, it will mess with my head a bit out there, even if that really isn't the case. Darnit, I wish I never would have read that rating on the sidewalls!

jerome951

This is true. A company picks a tire, measures the wear, and assigns it a rating of X. Everything else in their line is relative to this baseline tire. As we know, Hoosiers and the RA-1 both have the same 40 rating but far different wear rates.

Toyo made have made this adjustment from 40 to 100 to:
-- make the RA1 more interesting to people who want a performance tire that will last (thinking the 40 rating may scare off people)
-- make the rating more comparable to competitors relative tire wear ratings (i.e. indicate the RA1 wear has X times better wear than Hoosier, MPSC, etc.)
-- prepare for a new, softer compound (imagine trying to market a new tire w/ a -10 wear rating)

There are likely other scenarios that I can't think of right now.

Might want to post the question on the Wheel & Tire forum as there are some pretty knowledgeable tire gurus over there.

George A

I may be off here, but back in my AX days, a tire with a tread rating of 100 and above was considered a street tire and not an R compound tire. I'm not sure if that has anything to do with it.

George

tifosiman

I know that for PCA events, there has been a rule change for 2004 that hits you with upgrade points for any tires that have a treadwear rating lower than 140.

DGaunt

Very interesting thread indeed.

Yes, tire gradings are determined solely by the company and are not monitored by anyone. Some companies have historically plumped their ratings to appeal to the customer looking for a durable tire, perhaps relating durability to 'quality'.

140 is the average performance tire
100 is intermediate track tire
40-50 is an "R" compound tire.

There may be a way for you to guess if this is a compound change or just a tweaking of the UTG rating: Look at the DOT numbers and check the 5, 6, and 7th characters in the DOT number of the tire. This is the company spec designation of the tire. Only they know what it means, but if it is different, then you know the tire is too.

Another way to do it if the tires are relatively new is the colour stripes on the tread face. This is the way the factory assures the right 'green' tread rubber extrusion is sent to the right building station. If you can see two tires side by side you can tell if it is the same colour code.

Don't know how helpful this will be to you, but my $0.02