Tire Speed Rating

Messages
25,706
Location
Upstate NY
My 94 Camry wagon takes a H speed rated tire. The local Sams club will only install a H rated (or better) tire, but they do not carry any in the size I need. Another tire place in NY (Mavis Tire) says the speed rating is purely a speed rating and nothing to do with handling or sidewall strength. I believe they will install a tire with a lower speed rating like a S. So whats the real deal here, is the speed rating pursely speed and thus a S rated tire is fine for my Camry wagon?
 
Messages
699
Location
Texas
Although you may not utilitze the 'H' rated tire speed, its construction (including sidewalls) is much better than a 'S'. This really comes into play in emergency situations. Also, your car (esp a wagon) will handle differently with a lower rated tire. Don't skimp on tires...they are the most important safety device!
 
Messages
950
Location
Loveland, Ohio
IMO, it would be ok if you didn't exceed the speed rating. The tire has a load rating, and if you compare them you should be able to see if there is any difference in load ratings with the speed ratings. I think the higher speed ratings are needed to hold up to the higher heat buildup with higher speeds, might check some online sites, like www.tirerack.com. You could also direct the question to them. Definitely need to check with someone with ddirect knowledge on the issue....
 
Messages
3,932
Location
Somewhere in the US
Mavis Tire, huh? Good info, since they don't know what they are talking about. The truth about speed ratings is that: 1) As a general rule, the higher the speed rating the more responsive the tire to steering input. 2) As a general rule, the higher the speed rating the gippier the tread compound - and what comes along as a result is the more rapid the wear. 3) The higher the speed rating, the less likely the tire will fail. (You are using less of its capability) For these reasons, many tire shops will not install lower speed tires, but it's the last reason that has forced tire shops to re-evaluate how strongly they adhere to the rule (at the risk of losing a sale.) A lawsuit can be very expensive Hope this helps.
 
Messages
8,711
Location
Nothern USA
Speed ratings are over done. I doubt my 02 Cavalier with the Ecotec and 5 speed can get up to 130 mph the H rated tires it came with are good for. I don't think I would want an M. I cruise entirely too close its 81 mph rating. Tire stores forcing me to purchase tires good 130 mph when my car can't go that fast makes as much sense as H being between U and V. Maybe I could make do with a P or a Q and have a cheaper tire, quiet, soft riding, long wearing, and hold the road good in the wet. My wife is going to scream long before I reach it cornering limits.
 
Messages
2,387
Location
Chicago area
The speed ratings are to certify that the tire will hold up to the stated speed for 20 minutes, without failure. To me, better construction and materials is worth a little extra price. If you have a vehicle that only sees local trips at low speeds, you can get cheaper tires with no downside.
 

Donald

Thread starter
Messages
25,706
Location
Upstate NY
Oddly the current tires on the Camry to not seem to have a speed rating that I can see (OK...old eyes). I would guess my Dad had these tires installed maybe 5-6 years ago. So if the H tires are worth the extra $$, why would not everyone get H tires and forget the S rated tires. If Sams Club has only S rated tires in this size, that says the bulk of cars out there needing this size tire take an S. Why is Camry different?
 

Donald

Thread starter
Messages
25,706
Location
Upstate NY
Looked on TireRack for this vehicle and they do not push using H rated tires. They basically say that H rated tires are for Sports Sedans and Coupes. This is a Camry Wagon.
 
Messages
892
Location
LI, NY
Also keep in mind that tires that grip better stop better. I always use H rated tires, I would go "V" or higher but I use my car year round and have to deal with snow on occasions. BTW: I have talked to Mavis before, they were not knowledgable. Where abouts in NY?
 
Messages
699
Location
Texas
quote:
Originally posted by Donald: Oddly the current tires on the Camry to not seem to have a speed rating that I can see (OK...old eyes). I would guess my Dad had these tires installed maybe 5-6 years ago. So if the H tires are worth the extra $$, why would not everyone get H tires and forget the S rated tires. If Sams Club has only S rated tires in this size, that says the bulk of cars out there needing this size tire take an S. Why is Camry different?
LOL, look where you are at. Here we $$$ a bit more for better oil, we could all be using Wal-Mart ST, but instead some of us want the best! It's just personal choice. 3k OCI with ST is fine for most people, just like the 'S' tires. But for us "in the know" a few extra bucks for better performance is a no-brainer.
 
Messages
39,805
Location
Pottstown, PA
Yes, Winston. I learned about these back in 1974 in auto skewl.. They've added a couple since then. web page Speed Rating In Europe, where selected highways do not have speed limits and high speed driving is permitted, speed ratings were established to match the speed capability of tires with the top speed capability of the vehicles to which they are applied. Speed ratings are established in kilometers per hour and subsequently converted to miles per hour (which explains why speed ratings appear established at "unusual" mile per hour increments). Despite the tire manufacturer's ability to manufacturer tires capable of high speeds, none of them recommend the use of their products in excess of legal speed limits. Speed ratings are based on laboratory tests where the tire is pressed against a large diameter metal drum to reflect its appropriate load, and run at ever increasing speeds (in 6.2 mph steps in 10 minute increments) until the tire's required speed has been met. It is important to note that speed ratings only apply to tires that have not been damaged, altered, under-inflated or overloaded. Additionally, most tire manufacturers maintain that a tire that has been cut or punctured no longer retains the tire manufacturer's original speed rating, even after being repaired because the tire manufacturer can't control the quality of the repair. Over the years, tire speed rating symbols have been marked on tires in any of three ways shown in the following examples: 225/50SR16 225/50SR16 89S or 225/50R16 89S Each of these was an acceptable method of identifying speed ratings. Early tires had their speed rating symbol shown "within" the tire size, such as 225/50SR16. Tires using this type of branding were not to have been produced after 1991. 225/50SR16 112 mph, 180 km/h 225/50HR16 130, 210 km/h 225/50VR16 in excess of 130 mph, 210 km/h Beginning in 1991, the speed symbol denoting a fixed maximum speed capability of new tires must be shown only in the speed rating portion of the tire's service description, such as 225/50R16 89S. The most common tire speed rating symbols, maximum speeds and typical applications are shown below: M 81 mph 130 km/h N 87 mph 140km/h Temporary Spare Tires P 93 mph 150 km/h Q 99 mph 160 km/h Studless & Studdable Winter Tires R 106 mph 170 km/h H.D. Light Truck Tires S 112 mph 180 km/h Family Sedans & Vans T 118 mph 190 km/h Family Sedans & Vans U 124 mph 200 km/h H 130 mph 210 km/h Sport Sedans & Coupes V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars When Z-speed rated tires were first introduced, they were thought to reflect the highest tire speed rating that would ever be required, in excess of 240 km/h or 149 mph. While Z-speed rated tires are capable of speeds in excess of 149 mph, how far above 149 mph was not identified. That ultimately caused the automotive industry to add W- and Y-speed ratings to identify the tires that meet the needs of new vehicles that have extremely high top-speed capabilities. W 168 mph 270 km/h Exotic Sports Cars Y 186 mph 300 km/h Exotic Sports Cars While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire's 168 mph, 270 km/h maximum speed. 225/50ZR16 in excess of 149 mph, 240 km/h 205/45ZR17 88W 168 mph, 270 km/h 285/35ZR19 99Y 186 mph, 300 km/h Most recently, when the Y-speed rating indicated in a service description is enclosed in parentheses, such as 285/35ZR19 (99Y), the top speed of the tire has been tested in excess of 186 mph, 300 km/h indicated by the service description as shown below: 285/35ZR19 99Y 186 mph, 300 km/h 285/35ZR19 (99Y) in excess of 186 mph, 300 km/h As vehicles have increased their top speeds into Autobahn-only ranges, the tire speed ratings have evolved to better identify the tires capability, allowing drivers to match the speed of their tires with the top speed of their vehicle.
 
Messages
8,711
Location
Nothern USA
I still think it is insane to fuss about whether my car needs a tire that can go faster than it can. Putting an H, rated for 130 mph ona Cavalier is pure bling bling.
 
Messages
4,844
Location
Saskatchewan
quote:
Originally posted by CapriRacer: Mavis Tire, huh? Good info, since they don't know what they are talking about.
I disagree. The speed rating is independent of your "general rules". Yes; tires of higher speed rating are often grippier and usually handle better, but it is not inherent in the speed rating that the tire will have any of these qualities. A tire shop that tells you that you must have an H-rated tire is a tire shop that's trying to make more money off you. The DOT thinks an S-rated tire is fine for your car unless you are driving at highly illegal speeds. My V-rated Goodyear RS-A's aren't good tires, BTW. Even if they were the same price, there's a lot of S-rated tires I'd put on my car before I ever put those on again. [ October 25, 2005, 12:31 AM: Message edited by: rpn453 ]
 
Messages
1,904
Location
Bay Area, CA
I believe the whole speed rated thing started in Europe. The required speed rating for a tire was based on the cars top speed. Thus, a BMW would require a higher speed rating than Ford Escort. Of course, it is not uncommon for people to drive their cars at top speed on some roads in Europe. Now in the US, how often do you drive your car at top speed? I think even an S rated tire is rated for speeds up to around 95 mph. The only critical issue with speed rated tires is their resistance to failure at high speed. The whole issue about handling, etc is **. Every different brand of tire will handle differently. There are trade offs with every tire choice. The difference in handling/performance due to speed rating is insignificant compared to the brand/model of tire effect on handling.
 
Messages
3,932
Location
Somewhere in the US
There's more to speed rating that what appears on the surface. Garry Allan hinted at it with the quote he dug up. (BTW, where did you find that?) Here's some food for thought: The lab test that the speed rating is based on specifies a number of conditions that aren't necessarily the same in the real world. For example, the load / inflation combination is the maximum load and corresponding inflation pressure. When the test was put in place, this was a common vehicle specification. Nowadays, it's pretty common for the vehicle manufacturers to use a larger tire and specify a correspondingly lower inflation pressure. When these combinations are used for the test condition the same tire that would be H rated becomes T rated. There also been some work done on tire aging and, just like everyone thought, tires degrade with age. But it seems that the speed capability of a tire suffers more than other properties. The one study I saw indicated that a drop of 2 ratings within the normal life span of a tire. Of course this assumes that the tire is properly loaded (a pretty good assumption for passenger cars) and properly inflated (NHTSA studies show the 25% of pass cars are underinflated, so this is a bad assumption.) The net effect is that vehicle manufacturers have recognized and reacted to this information and have increased what they specify for speed ratings on their tires. (The criticism leveled at Ford was not wasted - not only at Ford, but at every other vehicle manufacturer as well.) I guess what I am trying to say is to be careful with thinking the speed rating is an absolute. Hope this helps.
 
Messages
139
Location
Bremerton, WA
Manufacturers set their governor chips to coincide with their tire's speed ratings, so i'm not sure it's completely without merit. If you look at Eclipses, the AWD's were originally sold with Z-rated (149mph+) tires, and as a result are not governed. The FWD eclipses however, were sold on H-rated tires, and because of that are governed at 129mph. I also buy the stickiest tires I can afford too, so, grain of salt, naturally. [Wink]
 
Messages
1,904
Location
Bay Area, CA
quote:
I still think it is insane to fuss about whether my car needs a tire that can go faster than it can. Putting an H, rated for 130 mph ona Cavalier is pure bling bling.
Keep it under 100mph and you should be OK with any tire. [Big Grin]
 
Messages
1,001
Location
Baltimore
quote:
CapriRacer: .... The truth about speed ratings is that: 1) As a general rule, the higher the speed rating the more responsive the tire to steering input. 2) As a general rule, the higher the speed rating the gippier the tread compound - and what comes along as a result is the more rapid the wear. 3) The higher the speed rating, the less likely the tire will fail. (You are using less of its capability) For these reasons, many tire shops will not install lower speed tires, but it's the last reason that has forced tire shops to re-evaluate how strongly they adhere to the rule (at the risk of losing a sale.) A lawsuit can be very expensive Hope this helps.
Apparently it's reason (1) that leads outfits like Hyundai to put H-rated tires on an Elantra that might do 100 mph going downhill being chased by a strong wind and being pushed by a Corvette. In general both owner's manuals and the tire manufacturers recommend not going down in speed rating, but realistically that Elantra can use T and S rated tires with zero safety worries. Btw, the speed rating is at the load and inflation pressure that the manufacturer recommends. If you increase or decrease the load, or increase or decrease the pressure, the performance of the tire at speed changes. The biggest single problem at higher speeds is heat, and so as the rating goes up, the flexing in the tread goes down, and generally the thinner the rubber is in both the tread and sidewall. Flexing leads to heat, and thick rubber has more trouble staying cool than thin. So, in general, as the speed rating goes up, tread wear goes down, and resistance to curb damage goes down. Your last point is a good one. Even if a tire failure is a result of someone letting their air pressure drop or curb damage, a lawyer who notes that someone replaced the OEM tires with lower speed rated ones could make a case. With all this mind I've dropped my wife's Toyota down a notch from the OEM speed rating. We run much higher than factory recommended inflation pressures and keep the car 20-25 mph below even the lower speed rating. I plan on doing the same to my new car, which came with H-rated tires, replacing them with tires that get better tread wear. .
 
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