Technology, Practicality Moving Us Closer to Fewer Speed Ratings

(Akron/Tire Review) For too many years, we’ve been explaining to our customers why they need speed-rated tyres. It’s the right choice, for example, if the vehicle came OE with a V-rated UHP radial. To make that rating, the tyre must be able to run at sustained speeds of up to 149 mph.

“But I don’t drive 149 mph,” the customer tells us. And, common sense says they’re right. If you drive that fast, your clothes will go out of style before you get out of jail.

About 30 years ago, speed-rated tyres seemed like a darned good idea. They arrived via Europe, where sporty performance cars and speed-rated tyres were all the rage. The tyres were so good that U.S. tyremakers, who were literally not yet up to speed, were embarrassed.

For some time now, we have been capable of building tyres that can handle speeds greater than 186 mph. One company’s newest UHP tyre is OE on the screaming-fast Ferrari F430 and designed for use on other exotics. Most tyre dealers have never seen an F430, let alone mounted a set of tyres on one.

Be careful here – the idea isn’t to berate tyre companies who can achieve this technical excellence. To the contrary, they should be applauded for putting together a myriad of complex pieces and parts in such a way as to allow such a tyre to be built.

The better question is this: What is a performance tyre in the 21st century? In fact, aren’t S-, T- and even H-rated tyres really today’s broadline tyres?

One company recently introduced a new tyre with a T-rated version backed by a 75,000-mile tread life warranty, plus H- and V-rated variations backed by a 60,000-mile tread life warranty. One tyre, three speed ratings.

Not that many years ago, you’d be hard pressed to find an H- or V-rated tyre with that kind of mileage backing – the kind formerly reserved for broadline radials. Not that unusual now. But isn’t it a bit maddening for a single tyre to be offered in three speed ratings, considering all of the obvious size/speed rating SKU combinations attached?

Consumers Still Don’t Understand

There is no doubt even the most astute customer is perplexed by all of this. You see it every single day. Here’s something from a BMW consumer Web site that helps make the case: “My 323 came with 225/50-16 tyres that are Z-rated, and it’s time to get new ones,” he writes. “My mechanic tells me the Z-rated tyres are designed for very high speeds, like 150 mph, but I might be happier with a less costly H-rated tyre, which would provide a longer tyre life as well.”

First the “mechanic” needs to know that, when a Z rating first appeared in a tyre size designation, the maximum speed rating for it was 149 mph. And then, things changed quickly. W and Y later subdivided that Z rating, pushing the max for a Z-rated tyre to 186 mph-plus, while W (up to 168 mph) and Y (up to 186 mph) filled the gaps down to the existing V (up to 149 mph) rating. In this way, the tyres met the supposed needs of new vehicles with extremely high top-speed capabilities.

Today’s sizing nomenclature also causes a pause. P275/40ZR17 93W tells us that this tyre has a W speed rating or a max of 168 mph. The speed rating now appears next to the load designation, not in the actual size.

Moving back to that customer’s online inquiry, an H-rated tyre means the Bimmer is now limited by a speed rating of just 130 mph. Although an H-rated tyre is a superior product, it cannot match the performance of a Z-rated tyre. It wasn’t built to do that.

There is also a misnomer that choosing a lower-speed-rated tyre will yield greater tread life. If the owner is used to driving Z-rated tyres and continues driving according to habit, an H-rated tyre may have difficulty keeping up with the owner’s driving demands.

Making matters more difficult for tyre dealers and consumers alike is the fact that there are now 30 different speed ratings, starting with A1, with a speed rating of a mere 3 mph all the way out to the Z for speeds above 186 mph.

Is that way too many? Would it be easier if we started with an S speed rating for standard passenger tyres, moved to a V for performance fitments and finally to a Z? That’s an easy question, but the answer may be tough.

Know Your ‘Ps’ and ‘Qs’

As you study speed ratings, some are reserved for very aggressive tread patterns found on winter tyres. Last month, we received more than a foot of snow in Akron. A P-rated winter tyre should not be driven faster than 94 mph; the Q-rating has a limitation of 100 mph.

Here’s the quandary: Not even Michael Andretti could have driven 94 mph down my street. Speeds in excess of 100 mph in those kinds of conditions would have put him high up in the trees.

But, here’s what the tyremakers are up against: What if these same tyres are left on a vehicle all year long? Driven in the summer, 94 mph is not only dangerous, but your customer will be lucky if those winter tyres last through September. But, that isn’t the point. No one can control or anticipate what consumers will do, so tyremakers are forced to deal with nearly every contingency. While the tread may be too aggressive and too soft to be driven in blazing heat without wearing out prematurely, tyre companies have to consider all the ‘what ifs.’

You Play a Big Role

Is it time to think of all drivers as ‘performance drivers?’ That Chevy Cobalt-owning accountant only needs to drive to work and back. To that person, tyre performance is just as important as it is to the ultra-high performance driver who muscles his/her way to work behind the wheel of a Ford Shelby GT 500. They both need reliable tyres, but their definition of performance is different.

The Cobalt driver is every bit as performance conscious as the driver of a much more powerful and expensive vehicle. They must arrive at work safely and on time through snow, rain, wind – virtually everything Mother Nature can throw at them. The same holds true for the driver of a Corvette Z06. The only difference is that one can only afford a Cobalt. But that doesn’t translate to performance vs. non-performance expectations. Both drivers need as much out of their tyres as tyre science permits.

The point is, you need to guide these drivers to the right tyre just as carefully as you’d deal with a F430 owner. Speed ratings are still a component of that sale.

Is It All Just Semantics?

Speed ratings like S, T and H don’t seem to be as relevant as they once were. The difference between an S-rated tyre (up to 112 mph) and a T-rated (up to 118 mph) is negligible. Moving up to an H (up to 130 mph) really isn’t that big a leap, but you’ll able to drive a bit faster.

While anyone can feel the difference between 112 mph and 130 mph, does that 18-mph gap really require three speed ratings? Even the most accomplished tyre guy has to wonder.

Consumers aren’t dumb. They know that, outside of a few rare areas, the highest interstate speed limit they’ll encounter is 70 mph. So, why do we really need so many options?

Look at it another way: Tyre dealers (and tyre companies) complain about the number of SKUs they are forced to deal with. A lot of that is driven by “required” speed-rating variations of the same tyre in the same size. How many SKUs could be eliminated by simply consolidating and eliminating certain ratings?

Sometime in the near future (if we’re lucky) an H-rated tyre with tons of new technology will be at the bottom of the scale. It will have all the traction, braking and handling properties you’d want – winter or summer – and carry a UTQG tyre-life rating of 400-plus.

Next on the speed-rating ladder will be a W with even more performance features, and finally, an unlimited Z-rated tyre with everything a true ultra-high performance driver could want.

When (and if) this happens, it lowers the number of SKUs and confusion among consumers and salespeople. There will continue to be many different aspect ratios, of course, to satisfy every type of buyer, so your front line people will have to be as sharp as ever.

But, instead of dealing with an outlandish range of speed variables and sidewall markings, they will be able to sell what consumers can’t see – the technology deep inside the tyre. Tread designs, compounds and more will separate one tyre from another and one type of tyre buyer from another.

I can’t wait.