Why tyre markings matter | PH Explains
We sat down with Michelin to find out just how crucial the code on your sidewall is...
No matter your budget, renewing all four tyres on your car can often feel like a chore. It’s the most crucial component of the lot - the only one connecting your pride and joy to the road - yet the bills it accrues are enough to make anyone wince. Time to pose the big question, then: just how crucial is it to keep your car replenished with the specific tyre designed for it?
“Tyre labelling grades are key in informing drivers about three key performance characteristics of a car and van tyre: wet grip, fuel efficiency and external noise,” says Michelin. “Nearly all new car and van tyres are tested to EU standards and given a grade in relation to performance. These grades are then displayed on new tyres with a label and can also be found in the EPREL (European Product Registry for Energy Labelling) database. Regulators can spot-check results, ensuring the label gives you a quick, trustworthy snapshot of performance.”
Which also means the * on the sidewalls of your BMW or the N stamped into your Porsche tyres are no mere gimmicks. “There is a long history of collaboration between Porsche and Michelin. In that time, our engineers have been able to develop tailormade tyres using special rubber compounds and custom-fit geometry developed for each specific model. Fitting tyres that aren’t N-marked may alter some performance characteristics, the Porsche engineers originally wanted you to feel.
“Equally, the * (star) marking means the tyre was jointly designed by the tyre manufacturer and BMW, meaning it has been developed and tested to ensure you enjoy the steering, grip and comfort BMW intended even years later.
“Vehicle manufacturers often work with tyre manufacturers to design and engineer tyres specifically for their models, taking into account transmission systems and other key components. If you wish to change to tyres that aren’t OEM approved, a suggestion would be to fit four identical tyres – but it is equally important to check with your vehicle manufacturer or local tyre professional whether those tyres are suitable for your vehicle.”
You should take heed of any XL (Extra Load) markings on your original tyres come replacement, too. “XL tyres are reinforced and are often recommended by manufacturers to carry heavier loads. If your vehicle weight does not require XL tyres, then there may be no additional benefit to using them.”
Which brings us to a pertinent question. Just how much pressure has the rising mass of SUVs, EVs and their frequent combination piled on the rubber below? “Car technology is changing, largely due to the introduction of hybrid and electric vehicles,” says Michelin. “Improvements to their range often mean a larger and heavier battery. The Tyre Manufacturer Association and ETRTO (European Tyre and Rim Technical Organisation) have defined a new High Load capacity tyre. They use the same pressures but offer a higher load-carrying capacity. HL will be marked before the dimension – HL 265/35 ZR20, for example, and if your original tyres are HL-marked you should continue to replace them with HL tyres. Like XL-marked tyres, if your vehicle manufacturer hasn’t opted for HL tyres from the factory, you don’t need to consider them.”
Given how carefully OEM fitment respects – indeed, elevates – the handling nuances of a car, should we be concerned that most cars sold in the UK are done so wearing so-called summer tyres, when inclement British weather often reduces the traction below us for large portions of the year?
“Vehicle manufacturers typically pick the tyre that best matches each model’s priorities such as ride comfort, braking performance, tyre longevity, responsive handling or rolling resistance.” says Michelin. “Depending on these priorities, summer tyres may be favoured to achieve some of these performance characteristics; however, some vehicle makers already sign off both summer and winter options, while more are now approving all-season choices such as Michelin’s CrossClimate from the factory. “In the replacement market, the shift is even clearer: all-season tyres such as the CrossClimate 2 are gaining popularity as drivers look for a set that can handle Britain’s mixed weather all year round.”
Tyre pressures are something PistonHeads readers likely consider more than most drivers, and they ought to be front of mind if you’ve opted to switch your car from its tyres’ factory dimensions. “We would always recommend following the suggested pressures from the vehicle manufacturer unless a tyre professional has advised otherwise,” says Michelin. “The vehicle manufacturer often sets inflation pressures based on its own understanding of its models’ load carrying capabilities and performance criteria. If you change a vehicle’s tyre dimensions, you may need to change the pressures used.
“Your best bet is to check with the vehicle manufacturer to ensure your new dimension is compatible and to check if there are suggested pressures available. If this is a bespoke conversion, it’s important to understand the load the vehicle is carrying before any suggestion can be made. If you want a specific tyre pressure recommendation or to chat about tyres, you can drop Michelin a line.”
Plenty of us own track specials or classics which only roll out of the garage occasionally, requiring a cautious eye despite their relatively low mileage. “Tyres are safety kit, so each one sold here must meet stringent construction and use regulations before it hits the road,” says Michelin. “But rubber ages: heat, cold, sunlight, storage and usage can all speed up or slow down the aging process. It’s important to check your tyre pressures regularly and look for signs of wear and damage. If you are unsure on what to look for, then it is important to consult a professional who will be able to advise on their condition."
For those of us with the dinkiest track toys and classics, hunting down appropriately sized tyres is no longer as simple as it used to be. “Michelin still produces 13” to 15” dimensions in limited sizes and will continue to do so for as long as there is a demand,” we’re assured. "Please check out our website or our Classic tyre range to see if your dimension is available.”
Sensible questions covered off, then, let’s round off with something we’ve surely all wondered but never dared voice: why are all tyres black, not least when concept cars have frequently promised us a more technicolour route to grip and stability?
“Over 200 ingredients go into making a tyre that each play a vital role in its characteristics. Natural rubber forms the main component of the tread layers, while carbon black and silica are used as reinforcing agents to improve durability. Carbon black is a key ingredient in tyre production, in fact, and not just for its colour. It increases tyres’ resistance to wear by protecting against UV (ultraviolet) light damage. So, no rainbow tyres just yet sadly.”
For the last 10 years I ve always made sure my cars have Michelin or Continental tyres regardless of the tread left when I purchase a car.
My Golf GTI had new Goodyear Eagle F1s that I switched out after 4-5 months for Michelin Pilot Sport 4s. The F1s replaced new Uniroyal Rainsports that I didn’t like.
208GTI went from something to Cross Climate 2s as wife daily drove it.
My M2 came with Michelin Super Sports that went for PS4s. Also bought winter alloys and tyres for snow.
Tesla is on Cross Climate 2s replacing whatever EV tyres it had previously.
I’ll always make sure I’ve the best tyre for the job which is typically Michelin.
Tyres improve all the time, I'd expect a 2000's spec tyre would feel a bit grim these days. It's also why I'm a little wary of the model specific tyres (though they did transform my MR2) as the technology is advancing quite rapidly. Or are we trading grip for rolling resistance and other environmental factors now?
Who buys a Porsche cayman and fits linglong tyres?
Wasnt there an article not long back where they fitted new tyres to the carrera gt and took seconds off its Nurburgring record? Shows how much tyre technology is advancing.
Subjectively even older everyday cars seem to be more likely to have a branded tyre in say Germany or France.
Outside of PH the U.K. seems to value tyres more on price than quality
t labelling system.Vendors will try and push the most profitable s
te onto buyers, telling them, "oh Michelin make these" etc etc, and they'll try and push it's an A or B rated tyre, same as say a top brand. Despite those labels being absolutely meaningless.There are no standards, manufacturers make up their own labels, and cheap Chinese tyres are oftenn dangerous, yet might label A or B in terms of performance.
But would we expect anything other than a scam from the EU ?
But given people, authorities, insurance etc etc give us s
t about fitting uprated parts to vehicles......why no outcry about fitting downgrade parts, critical parts....like tyres ?There are ample tests out there showing just how bad some "budget" tyres can be, and this was a pretty good example here. As well as the many dozens fo tests Jon has done on Tyre reviews. But this one takes a different approach.
https://www.youtube.com/watch?v=OMghLAsR4U8&t=...
God bless the a
holes who think this is somehow making us safer drivers. Yet it's fine if you fit a set of rock hard Chinese ditch-finders. Double your stopping distance - yeah, seems safe. Just but a good brand of tyre. It needs to be good enough. It doesn't need world beating aquaplaning results whilst cornering - just solid wet and dry grip, traction, and especially stopping distances. And the "designed for" b
ks - nah, come off it. It's just a load of rubbish designed to take money from fools. 
Got £10K off it, which made it the same cost as nearly-new, but got the colour and options I wanted.
Got £10K off it, which made it the same cost as nearly-new, but got the colour and options I wanted.
It was the colour and options she wanted surely...or does she just take what she is given with no input?
I am seriously struggling to believe that her (or more likely your) electricity charging costs could possibly be cheaper for a whole year than it would be for just one month in petrol.
A lot of people grossly underestimate the annual cost of charging an EV.
A lot of people grossly underestimate the annual cost of charging an EV.
A lot of people grossly underestimate the annual cost of charging an EV.
It isn't "all you can eat" at all, it is unlimited charging on days/times that they control, which is far from "all you can eat".
It is also "smart charging" so will likely involve an agreement to use the battery in the EV to back up the grid at other times.
Also, does not work with all car makes/charger types.
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