How important is OEM speed rating

[Jonny Z]

For some reason Toyota thinks the tires on a Camry SE P215/60R16 need to be V rated (in the manual and door jamb). They are expensive and wear quicker - my factory Toyo Proxes only last 20K mile.

I opt'ed for a set of Michelin Destiny of the same size, but only S-rated. I do think the factioy tires had a tick more tracktion, but the Michelins are 80K mile tires.

Am I wrong on the choice?

 

[CapriRacer]

There are several good reasons to go with the OE recommendations for size and speed rating.

The vehicle was tuned with the more responsive V rated tires. Putting lower speed ratings on will make the car more sluggish when turning.

The vehicle will take more distance to stop in the wet and the dry.

The tire will have less speed capability, which makes it just a little more likely to fail.

All in all, it's just going the wrong direction for safety.

 

[Huhwhye]

All stated above is very true, however I see no harm in getting a quality H rated tire for a car like a Camry(average family sedan). I think you would be giving up very little if anything at all on a car like that.

I would not get anything less than an H though.

 

[labman]

Will somebody explain why your need a tire rated for a sustained 130 that won't go 130? What a bunch of marketing bling bling nonsense

 

[Huhwhye]

You don't, its not about speed labman there's more to it than that.

Because the H tire generally (keyword generally) has a better compound that can affect handling, accelaration, braking compared to an S tire of similar size.

The higher the speed rating, other things improve too with respect to performance, generally.

It's not about top speed, its about grip and performance.

 

[csandste]

I used to own an Elantra that came with H rated Michelin Energies. I now have a Malibu Maxx with lower rated (T?) tires even though the 'Bu has 65 more horsepower.

1. Even though the Energies were the worst OEM tires I've ever had, that choice by Hyundai locked me into H rated tires from that point.

2. Hyundai probably paid about $15 per tire for these things. Michelin makes out like bandits because a percentage of them will get torn up and replaced for big bucks and a certain group of people will automatically replace with the same tire when they run out.

3. The Chevy OEM Bridgestones, although looking very mediocre on paper are much better than the Energies ever were. Although I'm not driving either car at 130 mpg, the Maxx has a heck of a lot more power.

4. Inherent handling of the two cars doesn't warrant the Michelins either since the Elantra was softer handling than the Maxx.

 

[csandste]

 

[CapriRacer]

There is another engineering aspect to this discussion that usually gets forgotten - (as my old college professor used to say) overdesign / underutlize.

When the vehicle is designed, everything spec'd for the vehicle should be more capable than is needed just to improve the odds that there won't be an equipment failure. This is true for bolts - SAE grade 5 bolts have a certain breaking strength and they are probably spec'd 2 to 3 times the calculated strength needed.

This would be true for tires as well.

Don't forget that the US models would probably have a chip in them to limit top speed, while the rest of the world would not, but the tires would be the same.

 

[rpn453]

"How important is OEM speed rating."

Personally, I believe it's a non-factor. I would never hesitate to install S-rated tires on a car that came with W-rated tires if S-rated tires are more appropriate for my conditions and budget. An example of this would be if you needed an actual all-season tire or winter tire. The high-performance versions are usually a joke if the pavement isn't clean, and they often don't last long so you quickly end up driving on tires with little tread depth. The D.O.T. says S-rated tires are OK for my car, no matter what I drive, and I very rarely exceed even 90mph.

Many of those higher speed-rated tires don't even do better than S-rated tires, which usually get an A rating, in the wet traction tests.

I'd love to be driving on some of the S and T-rated tires I've owned instead of the V-rated RS-A's that came on my Mazda3. I'm willing to pay a little more for a tire with a higher speed rating to get a higher quality tire, but the speed rating of the tire that came on the car will have absolutely no influence on what I buy.

 

[FowVay]

My personal opinion on this subject is that the load rating is more critical than is the speed rating for people that drive anywhere near the speed limit.

As mentioned previously, if you're not approaching the speeds that the tire is rated for then the superior carcass structure will likely not be utilized.

As for mileage ratings on tires,,, I feel that this is simply a sales ploy due to the many variables related to tire wear. The mileage rating is usually followed with a warranty that is prorated and results in the owner buying the exact tire again at a reduced rate and ensures repeat business at the place issuing the warranty.

 

[Alan]

csandste,

Did your Maxx come with Bridgestone Insignia 200's?

I got those on my new Corolla and they are decent tires.The newer ones supposedly use a new compound that's better in wet conditions.

 

[k1xv]

I have an old Infiniti Q45 that came with V rated tires. I went +1 with 16 inch wheels not long after I bought the car. Last Spring, I decided to go with a taller tire, with an H rating. All is fine. I never plan on going over 120 mph, and H is rated for 130.

I know some tire outlets, particularly the chain outlets, refuse to install a summer or all season tire with a lower speed rating than what originally came on the car. Yet the same places will sell you a snow tire with a significantly lower speed rating.

I fully agree that, all other things being equal, a higher speed rating results in more responsive handling at lower speeds. But I suspect there are a lot of H rated tires that handle better than some V rated tires.

Use common sense.

 

[bdcardinal]

ive actually upgraded the speed ratings on both my cars.

the first car is a 2000 Mercury Grand Marquis, it came with Michelin Symmetry S rated tires. after 60k miles when they wore out i went with Michelin Pilot Sport A/S W rated because of the better wet traction.

the second car is a 1998 Ford Mustang GT. the tires that were on it when i bought it were 245/40WR17 Sumitomo HTR+'s. they were decent tires, but would hydroplane very easily even with more than 5/32 tread. when they finally wore out, i went with 275/40YR17 Michelin Pilot Sport A/S, i put on 4 piston Brembo brakes and 17x9 konig villians when i put on those tires.

both cars had noticably better handling and definate better wet weather handling. plus with my lead foot, its nice knowing i can go fast if i have to. i actually track my mustang, and am looking at getting a set of Michelin Pilot Sport Cups for track use.

i work for a tire shop so i can get discounts on tires. our rules are that we can only drop 1 speed rating from factory. so if your car had V rated, we could put H on if you wanted. however we just arent allowed to mix speed ratings. i can say that it is very hard to find quality 17" tires that are anything lower than a V rating.

 

[Jonny Z]

quote:

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overdesign / underutlize

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I hear ya... but I was also taught to do the most with the least, if there is little to give up and much financial savings (The low miles on the high speed tires hurt), I could go for it. The S tires are softer, but I made up for it by inflating them to 35 PSI (Book says 29 PSI, but if you go over 100 mph, do 35 PSI)

quote:

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I know some tire outlets, particularly the chain outlets, refuse to install a summer or all season tire with a lower speed rating than what originally came on the car. Yet the same places will sell you a snow tire with a significantly lower speed rating.

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Discount Tires actually does not list a single V rated tire model for my car when I searched on their site. I think the highest rated is H.

quote:

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My personal opinion on this subject is that the load rating is more critical than is the speed rating for people that drive anywhere near the speed limit.

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The load ratings are exactly the same. 94 I believe. Isn't load rating dictated by the size of the tire?

 

[bdcardinal]

load rating is based off of the size in a standard application. you can get higher load ratings B,C,D, E, and F for trucks. finding the higher load range tires in passenger car sizes is very difficult. ask anyone with a Vanagon who has tried to purchase tires recently. i know michelin stopped making tires for them, as well as almost every other tire company out there.

generally Michelins have a stronger sidewall than other companies.

 

[slugsgomoo]

quote:

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Originally Posted by k1xv: I have an old Infiniti Q45 that came with V rated tires. I went +1 with 16 inch wheels not long after I bought the car. Last Spring, I decided to go with a taller tire, with an H rating. All is fine. I never plan on going over 120 mph, and H is rated for 130.

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Probably makes sense. My buddy has a 94 Q45, and runs Z-rated tires, though I know he's bounced the limiter a couple times in the desert- (155.5mph) It's pretty fast for a big ol' behemoth like that.

I'll take traction over treadlife any day of the week (to an extent, I guess) and a 20k mile tire seems like a **** of a good deal to me.

Saving a couple bucks a year by having a tire that grips significantly less, and just lasts longer seems like a misplacement of priority.

 

[Bamaro]

I agree that speed rating as recommended by a manufacturer is pretty useless unless you plan to drive at that sustained speed. A higher speed rating does not necessarily translate into better performance.

 

[Tremo]

My Camaro came with V rated tires, but I've been running Z rated tires on it. they're very responsive and very smooth and stable at highway speeds.

I did once did a speed run with it. I chickened-out as it was accelerating up past 130. It was still pulling, but I didn't want to have to change my shorts. Road and Track said it should do about 145, I'll take their word for it.

 

[Brikhead]

quote:

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I did once did a speed run with it. I chickened-out as it was accelerating up past 130. It was still pulling, but I didn't want to have to change my shorts. Road and Track said it should do about 145, I'll take their word for it.

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...and this was done legally, on a race track...right?

 

[slugsgomoo]

all speeding is done on a racetrack.

I did 142mph on S rated tires, on the local "racetrack" and they developed the most horrific "thump thump thump" going down the road. Apparently that is not recommended. They got swapped out for Z rated tires, and I haven't been to the track to see if I could go faster since.