I went to one of the 'national' tire dealers recently to price replacement tires for my Subaru. They were trying to push a T rated tire on me. When I inquired about a different brand in my size that was H rated as is the OEM spec for my vehicle, it was out of stock. I wouldn't have minded if the dealer would have explained that he was deviating from OEM requirements by suggesting a T rated tire. It irked me that they were pushing the wrong tire on me as it was what they had in stock. Costco refused to sell a friend of mine a tire they had in stock that didn't meet OEM speed requirements. It pays to do your homework as they will do anything to make a sale and are looking out for their interestsand not yours.
Do tire dealers think EVERYBODY lacks knowledge
- Thread starter Joe1
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What's wrong with T-rated? Are you really gonna exeed their speed limit? Other than that they are the same as their H-rated version, compaund and profile vise.
Say again? Exactly how do you know, especially given that the particular tire and size wasn't given? The particular Subaru model wasn't even specified.
Some tires of the exact same model/size come in different load ratings. Others come in different speed ratings. There could be differences in compound, although I'd think a difference in belt construction is more likely.
The are three different 205/55R16 versions of the Bridgestone Potenza RE92. They all have the same load rating but have different tread widths and possibly different belt construction.
If it was Goodyear, they've been on strike for months. Dealers are lucky to have anything in the right size to sell. Tire dealer kids have to eat too!
Bob
Bob
Actually, I think what you encountered was a lack of knowledge on the part of the salesguy.
But let's face it, sales folks are only interested in selling - they don't care much for the "technical restrictions" - and that would include the speed rating issue. Either the national chain doesn't realize how much legal liability they have, or the salesguy decided on his own to ignore it - especially when he knows he doesn't have the "right" tire in stock.
But let's face it, sales folks are only interested in selling - they don't care much for the "technical restrictions" - and that would include the speed rating issue. Either the national chain doesn't realize how much legal liability they have, or the salesguy decided on his own to ignore it - especially when he knows he doesn't have the "right" tire in stock.
you pretty much answered your question yourself. usually higher speed rating means different tire construction. That's all the difference. and if you're not planning on exeeding speed limit of that tire's speed rating, it's irrelevant to you. compound,tread pattern and other tire's performance characteristics usually stay the same in those tires anyway, regardless of a different speed rating.
oilnoob,
There is more to selecting the right tire than the speed rating. An S-tire is rated for 112 mph. A P-tire is rated for 93 mph. Now I won't be going over 93 mph so why not just try to find a P-speed rated tire? Why would you not go lower than the T? A tire's speed rating is more than just telling you how fast you can travel on said tire.
P - 93 MPH
Q - 99 MPH
S - 112 MPH
T - 118 MPH
U - 124 MPH
H - 130 MPH
V - 149 MPH
Z - 149+ MPH
W - 168 MPH
Y - 186 MPH
There is more to selecting the right tire than the speed rating. An S-tire is rated for 112 mph. A P-tire is rated for 93 mph. Now I won't be going over 93 mph so why not just try to find a P-speed rated tire? Why would you not go lower than the T? A tire's speed rating is more than just telling you how fast you can travel on said tire.
P - 93 MPH
Q - 99 MPH
S - 112 MPH
T - 118 MPH
U - 124 MPH
H - 130 MPH
V - 149 MPH
Z - 149+ MPH
W - 168 MPH
Y - 186 MPH
What's more to it then? Please do tell.
I agree that the lower speed rating issue should have been brought up by the salesperson.
However, if someone tried to tell me that I couldn't buy a tire because of a speed rating, I'd walk out and write them down on my blacklist of businesses I'll never return to. That's equivalent to a salesperson refusing to sell me a vehicle that only has a 4 star safety rating, except that I'd much rather have a 5 star vehicle with S-rated tires than a 4 star vehicle with Y-rated tires. I've never had to do that though, probably because I tell them only what size I want, not what vehicle it's going on. I do have a few on the list that have tried to convince me that studded tires are obsolete!
I do like buying decent tires though; other than winter tires, every tire I've ended up buying has had the OEM speed rating or better. If I'm ever going down a long 20% grade with a 200 MPH wind at my back and no brakes or engine braking in my Mazda3, my Y-rated tires will be put to good use!
However, if someone tried to tell me that I couldn't buy a tire because of a speed rating, I'd walk out and write them down on my blacklist of businesses I'll never return to. That's equivalent to a salesperson refusing to sell me a vehicle that only has a 4 star safety rating, except that I'd much rather have a 5 star vehicle with S-rated tires than a 4 star vehicle with Y-rated tires. I've never had to do that though, probably because I tell them only what size I want, not what vehicle it's going on. I do have a few on the list that have tried to convince me that studded tires are obsolete!
I do like buying decent tires though; other than winter tires, every tire I've ended up buying has had the OEM speed rating or better. If I'm ever going down a long 20% grade with a 200 MPH wind at my back and no brakes or engine braking in my Mazda3, my Y-rated tires will be put to good use!
Better tire construction is never a bad thing. It's very, very rarely necessary, and the driver could almost always be blamed for situations where it is, but it is an extra degree of safety. Now, when they have to compromise the all-season capabilities of the tread pattern to get the higher speed rating . . .
I never said it's a bad thing. I said higher speed rating is not always neccessary. And i meant performance characteristics within a same tire model of course.
Tread patterns usually change a little with speed rating, even for the same model of tire. The V-rated RS-As that came with my Mazda3 should be classified as summer tires, while the H-rated ones on my mother's Sunfire are semi-competent in the snow.
You answered your own question in your 2nd post of this tread - different tire construction. For a tire to go from T-speed rated to H-speed rated requires a better tire IMHO. I'm not saying that the higher speed rating is absolutely necessary either. But as CapriRacer pointed out, I would imagine the shops have quite a bit of liability, in our litigious society, that their name will be on the lawsuit & they will lose if they sell & install a less-than OEM spec tire. Heck, they would probably lose anyway, but this is their best shot at not having to pay out the nose for the lawsuit.
It appears this salesman was trying to make a quick sell as most people won't wait for tires to be ordered & come in - they will simply go to the store down the road.
It appears this salesman was trying to make a quick sell as most people won't wait for tires to be ordered & come in - they will simply go to the store down the road.
i knew that already. but you made it to sound like there was a lot more to it than just different construction. and i'm not laking about all those legal stuff in here. i only care about speed rating disscussion. thanks.
p.s. you are wrong. different speed rating changes tire's performance category(you can go faster), but doesn't change it's weather performance(if it's performance all-season now it just touring all-season) compaund and tread pattern STAYS THE SAME.
sorry my p.s. was addressed to rpn453 post: "Tread patterns usually change a little with speed rating, even for the same model of tire. The V-rated RS-As that came with my Mazda3 should be classified as summer tires, while the H-rated ones on my mother's Sunfire are semi-competent in the snow."
where is that #@$%! edit button when you need one ?!!
where is that #@$%! edit button when you need one ?!!
I'll assume that you're talking to me on that one, and I'll book an appointment for the optometrist! I had them side-by-side, and they were different.
Yes I was. how different? size wise? summer and all season is a two different things. different speed rating cannot affect that. allseason tire simply can't magically turn into a summer tire by just simply changing it's current speed rating to higher speed rating. that's all i'm trying to say.
Sorry, I think I misunderstood you a little.
What I'm saying is that tread design can also affect the speed rating, because more aggressive tread designs generally have more rolling resistance and contribute to increased tire temperatures at higher speeds. If you built a tire with the basic construction of my Y-rated Michelin Pilots, but with the tread design from my T-rated Cooper Weathermaster winter tires, I don't think it would be Y-rated anymore. It would probably go up a bit, maybe to an H-rating, but I can't see them being suitable for 186 mph. I'm sure they would also howl to indicate how much pain they are in at that speed! I believe that is why tires like the Goodyear RS-As and BFG Traction T/As have a more aggressive, all-season oriented tread in the versions with lower speed ratings.
Boy, I hate to get in the middle of this argu....mmmm......discussion, but I have to correct some misconceptions.
Speed rating is a capability that a tire has. It is based on a test where a new tire is mounted in a fixture in a 77F temperature room and loaded against a wheel and the speed is increased in a series of steps. To pass a given speed rating, the tire must endure one hour at the rating speed. Usually this an "after the fact" kind of thing because the speed rating is usually a given in a line of tires, and the test is more like a compliance type of thing.
What this means is that old tires, ambient temperatures above 77F, something other than glass smooth roads, something more than one hour accumulated at speed are all in the wrong direction.
In other words, there is lot more than just the speed when we talk about speed ratings. And it's not an absolute!!!
For practical purposes, the tire construction is pretty much the only thing that is different from speed rating to speed rating.
HOWEVER.....most higher speed rated tires go on higher peformance vehicles and those tires have to be sized and designed accordingly.
So generally the higher the speed rating, the lower the aspect ratio, the lower the treadwear rating, the better the grip (treadwear and grip are pretty much mutually exclusive). This also means that higher speed rating, the more likely the tire is to be a summer tire.
And the reason I decided to post:
Rolling resistance is pretty much a function of 2 things: The tread compound and the amount of material in a tire, especially in the tread area.
Put another way, the tread design hardly affects the RR. But this all gets confounded by that fact that summer tires are generally thinner treaded but have a high grip (read high RR) compound, while all seasons have more tread rubber, but the tread compound is much better for RR (lower grip).
Winter tires are the worst of both worlds - lots of tread rubber and a grippy compound - and therefore high RR.
All this leads a lot of folks to think that the tread pattern grip has something to do with RR - it does not!!
Now to complicate matters further, cap plies - which are almost required for an H and higher speed rating - add bulk in the tread area and add significantly to RR.
Now for my 2 cents:
Adding a cap ply to a construction adds much more than would be indicated by the increase in speed rating from T to H. In fact some "experts" say that all tires should have a cap ply, because they are so much less likely to fail. Of course if you look at the test and understand what the result will mean - well...my interpretation is that folks in the great white north don't need to worry much about speed ratings S or lower, but the folks in Arizona have to be concerned because of the temperature.
The National Highway and Traffic Safety Adminsitration (NHTSA) studied tire failures by state and the top 5 were: AZ, CA, TX, NV, and FL. I'm not sure about the order but it was something like that. Also, this was NOT normalized for the population. Normally I include NM which I don't think made the list because of the low population.
Based on what I know, I think you absolutely have to have H rated tires in those 6 states. The further north, the less the need.
Speed rating is a capability that a tire has. It is based on a test where a new tire is mounted in a fixture in a 77F temperature room and loaded against a wheel and the speed is increased in a series of steps. To pass a given speed rating, the tire must endure one hour at the rating speed. Usually this an "after the fact" kind of thing because the speed rating is usually a given in a line of tires, and the test is more like a compliance type of thing.
What this means is that old tires, ambient temperatures above 77F, something other than glass smooth roads, something more than one hour accumulated at speed are all in the wrong direction.
In other words, there is lot more than just the speed when we talk about speed ratings. And it's not an absolute!!!
For practical purposes, the tire construction is pretty much the only thing that is different from speed rating to speed rating.
HOWEVER.....most higher speed rated tires go on higher peformance vehicles and those tires have to be sized and designed accordingly.
So generally the higher the speed rating, the lower the aspect ratio, the lower the treadwear rating, the better the grip (treadwear and grip are pretty much mutually exclusive). This also means that higher speed rating, the more likely the tire is to be a summer tire.
And the reason I decided to post:
Rolling resistance is pretty much a function of 2 things: The tread compound and the amount of material in a tire, especially in the tread area.
Put another way, the tread design hardly affects the RR. But this all gets confounded by that fact that summer tires are generally thinner treaded but have a high grip (read high RR) compound, while all seasons have more tread rubber, but the tread compound is much better for RR (lower grip).
Winter tires are the worst of both worlds - lots of tread rubber and a grippy compound - and therefore high RR.
All this leads a lot of folks to think that the tread pattern grip has something to do with RR - it does not!!
Now to complicate matters further, cap plies - which are almost required for an H and higher speed rating - add bulk in the tread area and add significantly to RR.
Now for my 2 cents:
Adding a cap ply to a construction adds much more than would be indicated by the increase in speed rating from T to H. In fact some "experts" say that all tires should have a cap ply, because they are so much less likely to fail. Of course if you look at the test and understand what the result will mean - well...my interpretation is that folks in the great white north don't need to worry much about speed ratings S or lower, but the folks in Arizona have to be concerned because of the temperature.
The National Highway and Traffic Safety Adminsitration (NHTSA) studied tire failures by state and the top 5 were: AZ, CA, TX, NV, and FL. I'm not sure about the order but it was something like that. Also, this was NOT normalized for the population. Normally I include NM which I don't think made the list because of the low population.
Based on what I know, I think you absolutely have to have H rated tires in those 6 states. The further north, the less the need.
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