Tyre shopping can be confusing. The most popular tyre size in the UK is 205/55 R16, but if you search for this on any online tyre retailer, you get presented with a myriad of options.
205/55 R16 91T, 205/55 R16 91H, 205/55 R16 91V, 205/55 R16 91W, 205/55 R16 91Y, 205/55 R16 94H XL, 205/55 R16 94V XL, 205/55 R16 91W XL.
It's common knowledge all these tyre sizes exist, but it's less known that they could all be exactly the same tyres.
With the introduction of the Michelin CrossClimate and Pilot Sport 4, Michelin will now only be making the highest load and speed rating version of the tyre, meaning in the above example, the produced tyre would be the 205/55 R16 94V XL, which would be suitable for any 205/55 R16 fitment.
The benefit to retailers and the supply chain is huge. Instead of having to stock eight different tyres, they can now stock one, and it makes shopping for tyres online a whole lot easier for the consumer too. But what about any negative aspects of using the higher load and speed rated tyre on a vehicle originally specified with a lower option?
The Law and Insurance
Legally, and from an insurance standpoint, you're absolutely fine using a higher load and speed rating. The law says your tyres must at least meet the minimum load rating, so if a car is specified with 91 rated tyres, 91, 94 and 98 are all fine. Speed rating is even less strict, with cars specified with 91V summer tyres often specifying 91H winter tyres.
The other potential negative aspect of using a higher rated tyre is a loss of comfort, extra noise and reduced MPG due to weight, but fortunately in the real world the difference is negligible, or often nothing.
For the Michelin Primacy 3 in 205/55 R16, the 91V version of the tyre weighs 8.948kg, while the 94V XL version weighs in at 8.964kg, just 16g heavier, which will be unnoticable from a fuel consumption and comfort / noise point of view.
Michelin are doing an interesting job trying to simplify the world of tyre shopping, and if other manufacturers follow suit, the entire supply chain from production to a customer having the tyres fitted is about to become a whole lot simpler.
But the example's not the highest speed rating of those mentioned (Y), or even those for the 94 load index (W)!
It's not something Michelin are doing for selling a more "expensive" tyre. It is purely to try and simplify the process, for us, dealers and consumers. It's actually meaning we risk losing sales, especially if a dealers screen searching for a 91V doesn't see the 94V we make. But we feel making so many options with minimal differences just over complicates things
It's my understanding from tyre load charts that XL rated tyres require a slightly higher pressure to reach the same load capacity as a non XL tyre. Take the above example that the 91V tyre with recommended pressure of 33psi, would need to be replaced with a 94V tyre with 35psi. Taken that the vast majority of road users run underinflated anyway, I wonder if this would be any safety issue for a fully loaded car driven long distance, heat for example?
Not really for absolute majority of cases, and specially not in winter...All new cars have TPMS pressure leak sensors and the difference of 2 psi is negligible. Plus the new tyre compounds are much less heated when rolling than previous generations. Howgh.
It's quite complex and depends a bit upon the legislation required by the ETRTO regs
Simply run the pressures for a standard tyre in an XL tyre
The addition of a slightly higher pressure for max loading on an XL is almost like a double safety element
It ensures that XL tyres can take extra load even in some cases where the construction of the tyres aren't significantly different
Most road cars have tyres that are way over the maximum weight of the car laden so if the tyres are at the recommended pressures they'll cope with the load very easily
My car requires 225/45/R17 91Y tyres. It's currently fitted with Goodyear Eagle F1 Asy3's, and when I was last shopping for tyres 225/45/R17 94Y were also available but a couple of quid more expensive per corner. The cynic in me thinks that this is probably at least part of their motivation.
Interesting you are using speed index Y, because it means your car has Vmax=271-300 km/h... But though in some EU countries you can save your money by using lower speed index (W,V,H, even T means cheaper tyres) for winter tyres when you put in front of the driver (or as a limit alert in your board computer) a sticker with that lower max. speed. The question is if it is authorised also in the UK and for all season tyres, which I don't know.
P.S. Newest UK all seasons tyre test is from the Auto Express magazine testing 17” size, 225/45R17: And the winners are...
You are allowed to use a lower speed rating in the UK, but NOT a lower load rating than specified.
Interesting you are using speed index Y, because it means your car has
Vmax=271-300 km/h... But though in some EU countries you can save your
money by using lower speed index (W,V,H, even T means cheaper tyres) for
winter tyres when you put in front of the driver (or as a limit alert
in your board computer) a sticker with that lower max. speed. The
question is if it is authorised also in the UK and for all season tyres,
which I don't know.
P.S. Newest UK all seasons tyre test is from the Auto Express magazine testing 17” size, 225/45R17: And the winners are...
My Honda FRV has traction control called VSA.
In the manual it says that you must fit 205/55 R16 91V not 94V for the traction control to work.
We fitted 4 x Crossclimate 94V to our car last year and have noticed a few more traction control events since. Is this a coincidence?
If you are fitting four, it's more likely to be coincidence. Whilst calibration of most Traction control systems is integral within the ECU, e.g. suffice to the car having the same tyres all round most systems will learn and adapt
I'm happy to help (I'm Technical Engineer for Michelin UK) if there's anything else we can do
One wonders if there will still be, say, 3 versions of a 94V though - with different qualities across the parameters of tyre performance (especially for different markets around the world). So, one 94V optimised for wet grip, another for rolling resistance & comfort, another for longevity & impact resistance & so on. If so, then, nice though the standardization of 94V would be, it would not be one tyre & would still be a "lucky (or unlucky) dip" as to what variant one was getting if it were to be opaque (as in current practice) just what variant had what performance parameter profile.
My issue is not with the variants' existence so much as the near total lack of information as to the comparative properties of the variants (even, in my experience, when one asks a company's "front desk" tech people (they don't know & can't access answers).
No premium tyre manufacturer would bring different tuned versions of the tyre to the same market without OE marking them.
We believe this problem has only arisen in the past when tyre dealers import tyres illegally from different markets in order to buy them cheaper.