bobkart
Well-known member
I'm not trying to dissuade anyone from buying their tires/wheels/etc. from TireRack. It's more of a heads-up that what's advertised on their website might not be accurate. And that not every customer service representative understands things like inflation pressure and treadwear ratings.
bobkart said:These wheels and tires showed up today. When I compare what's written on the tires with what your website advertised them as, I see two problems.
First, these tires were advertised as having 51psi maximum inflation pressure. But written on the tire is 44psi. I used that specification as part of my decision-making, and now I see that it was misinformation.
Secondly, the treadwear rating on these tires was advertised as 400, but these tires have 500 written on them. Again this was a factor in deciding to purchase these tires, yet it failed to actually be true. I understand that 500 instead of 400 means the tires should last longer, but conversely, 500 instead of 400 means the tires are likely that much less sticky.
What is going on here? Did I get shipped different tires from what I ordered? What is the point of having specifications for tires people are deciding between if those specifications won't actually match what they get?
TireRack said:This tires branding was updated to 500 AA A and 44 max psi per the manufacturer. They advised that the tire’s performance should be the same or previous rating, as the construction has not changed.
bobkart said:So when you say "the tire's performance should be the same", does that mean I *can* safely fill these to 51psi? (Tolerable inflation levels being part of the overall "performance" of a tire.)
Also, when you say "the construction hasn't changed", that may be true, but treadwear ratings are more about the *compound* of rubber used, not the construction. So to achieve the higher treadwear rating, they may have hardened the compound, which will likely lead to less grip. People routinely use treadwear ratings to assess grip (lower rating suggestive of higher grip, "all other things equal").
Also, I would have preferred to know what the real specifications were *before* I placed an order. My question then would be why the advertised specifications (on your website) aren't kept up to date with what the true specifications are.
TireRack said:Why would you fill to 51 psi when this vehicle recommends 36 psi?
bobkart said:That doesn't answer my question.
I can answer your question easily, but first expect an answer to mine.
And that wasn't my only question.
TireRack said:You can safely fill to the maximum shown on the tire, which Is 44.
bobkart said:That's what I'm talking about then. The performance of the tire *is* different from what was advertised. The tires I ordered could be safely filled to 51psi. The tires I received can only be safely filled to 44psi.
As to why fill them higher than recommended, it's well known among Leaf owners that the 36psi recommendation leads to abysmal rolling resistance compared to higher numbers like 44psi. Advice is routinely given and followed to fill them higher than recommended, for better energy efficiency. I personally have seen this improvement, as has most everyone reporting back on their experiences after trying it.
Also, anyone who has ever used their vehicle in a competition situation (Autocross for example) understands that increasing tire pressure over recommended levels will (up to a point) yield better tire performance.
TireRack said:The treadwear rating is an indicator of how long the tire is expected to last, compared to a “benchmark” tire. Treadwear rating literally has nothing to do with how much grip the tire can generate. Anecdotally, there is a general correlation between lower treadwear numbers and more grip, but it is not a causation effect, nor is it a direct correlation. A tire manufacturer can, and many have in the past, change(d) the UTQG treadwear rating on a tire while not changing anything else about it.
I understand your point about not receiving what was advertised. Our site was not updated because we were not made aware of the change when they were sold.
In the end, if you are not happy with these tires, we can have them returned under Continental’s 60-day customer satisfaction warranty. They would require that you purchase another Continental or General tire brand to replace these tires under this warranty.
I completely disagree with this:
> Treadwear rating literally has nothing to do with how much grip the tire can generate.
There *is* a correlation, as evidenced in this article:
https://blog.tirerack.com/blog/motorsport-messages-from-marshall/utqg-treadwear-numbers-what-do-they-mean
Yes it's not a perfect correlation, and note I only said "suggestive of higher grip" and especially "all other things equal".
Of course a manufacturer can change those numbers without any other change to the tire. Certainly if they were "wrong" (less reflective of reality) before the change than after.
Still, given two tires of identical size, tread pattern, construction, ... ("all other things equal"), if one tire's compound yields twice the tread life as the other, it's a sure bet that the tire with the shorter tread life *will* yield higher grip levels (unless the manufacturer really screwed up and just built a tire with a quickly-wearing compound that had no upside to that compound-choice downside).
No need to reply this this message. I see your other 'last word' on this as 'return them to Continental if you don't like them (as long as you replace them with another of their products)'. I will make them work for my application. My point is that they were decided on using information you advertised that wasn't true. I.e. I may have made a different choice had I know the truth.