What do the markings on my tyre sidewalls mean, and are they important?

Ever taken a moment to look at all the information that’s displayed on the sidewall of your tyres? Some of it’s easy to comprehend, such as the tyre manufacturer – for instance, Continental – and the product name – “ContiPremiumContact 5”, for example – but the rest can seem to some to be an unfathomably complex code, which is very confusing.

What does it all mean? It’s worth asking the question, because the information reveals a lot about not just your tyres but your car too.

On the whole, most drivers know how to find their tyre size. It’s typically displayed as a set of four characters – for example “205 55 R 17” – but other than that, the majority of motorists tend to ignore the rest. Which could be a mistake, particularly if you care about the car you drive and want to get the most out of it.

Tyre size on a tyre sidewall

If you happen to drive any model of modern day Audi, BMW, Jaguar, Land Rover, Maserati, Mercedes-Benz, Mini, Porsche or Tesla, and want to fully enjoy the full driving characteristics of your vehicle, you definitely shouldn’t ignore your tyre sidewalls. If you do, and make the mistake of fitting a tyre that isn’t the same as those that came with the car as new from the factory, you’ll compromise your vehicle’s optimum performance settings.

Why? Because these tyres have been specifically developed for your model of car, in a partnership between the automotive and tyre manufacturers, so that they can bring out the best characteristics of your vehicle.

“Homologated” tyres

The automotive industry term for a tyre that’s been developed and approved by a vehicle manufacturer is “homologated”. Each individual car maker can be identified on the tyre sidewall using their designated code. There are many, with some easier to decode than others – Mercedes, for example, is MO, and Audi is AO, but others are a little trickier to identify. N1? No, not Nissan – it’s actually Porsche. “Homologation” is a bit of a mouthful and, let’s face it, the majority of drivers aren’t familiar with the term. An alternative term is Original Equipment – “OE”.

Homoglated tyres Continental graphic
Example of an OE tyre for Audi – manufacturer code “AO”

Manufacturer                             OE Key

Audi                                             A0, A01

Audi quattro                                 RO1, RO2, R03

BMW                                           *

BMW / Mercedes                        *MO

BMW / Mercedes Runflat           *MOE

Jaguar                                         J

Land Rover                                 LR

Maserati                                      MGT

Mercedes-Benz                          MO, MO1

Mercedes-Benz Runflat              MOE

Porsche                                       NO, N1, N2

Tesla                                           TO

Quick guide to car tyre sidewall markings

Sidewall description graphic Continental

Homologation leads to the best tyres for your car

So what is the homologation process? First, a tyre manufacturer, like Continental, researches and develops, extensively tests and then produces a new, generic tyre. Their very popular, award winning ContiPremiumContact 5 is a great example – an extremely high-quality premium tyre that can be fitted on a wide variety of vehicle makes and models.

At this stage, the world’s leading automotive manufacturers – especially the prestige marques – begin testing this generic tyre to see how well it performs with their specific vehicles. They exhaustively scrutinise a wide range of criteria, for example the tyre’s weight, grip, performance and handling characteristics. At the heart of what they’re testing for is whether or not the tyre helps to bring out the key attributes that the car itself has been engineered for – such as its handling. This process is very intensive, since the automotive manufacturer is determined to only pair their vehicle with the very best tyres.

Once the examination is complete, feedback is digested by the tyre manufacturer, and all necessary modifications and adjustments are made to suit the needs of any given specific vehicle model. When this process is completed, the homologated version of the tyre is approved by the vehicle manufacturer, and then produced – bearing the car manufacturer’s homologation code on the tyre sidewall.

It can take up to two years to complete this thorough and painstaking process, which is why the selection of homologated tyres is typically limited to just premium tyre manufacturers, like Continental. And the result? Exclusive premium tyres fitted at the automotive manufacturer’s factory that work in perfect harmony with your car.

Can you really notice the benefits of homologated tyres?

Absolutely. Imagine you’ve bought a three year old Audi. You bought it because you love the car, its sporty suspension, super tight handling, and superb acceleration. And then – a year later – you need to change the (generic) tyres. Asda Tyres then recommend you fit homologated ContiSportContact 5P – approved by Audi for your car. You buy them.

So, what will you notice with homologated tyres? More than anything else, it’s that the characteristics you already love about your car are now so noticeably improved. The ride feels even better, the handling feels that much tighter, and – when you accelerate – you really feel the oomph! And let’s not forget, there’s also the superior grip that premium tyres provide, delivering sharper, quicker braking, and reduced stopping distances (especially in wet weather conditions).

Homologated tyre testing on an Audi by Continental

So are homologated tyres much safer than generic tyres?

All generic non-homologated premium tyres are superbly engineered and manufactured to deliver optimum handling, grip and braking performance. This level of excellence – especially when compared to cheaper tyres – is indisputable, and meets the needs of most drivers.

However, compared to the bespoke homologated versions fitted for a specific car model? There’s no comparison. Homologated tyres are noticeably better, since they’re specifically built to the vehicle manufacturer’s exacting requirements. It’s like comparing an off-the-peg Armani suit to one made bespoke for you by the great man himself. Both are excellent, but you can feel the difference in quality and fit between one and the other.

There is often occasion for technologies to be added to the tyre to fulfil the car manufacturer’s needs, or the rubber compound ingredients are tweaked to make sure the tyre works exactly how the manufacturer intends. Sometimes the tread pattern may need modifying. As when tailoring a suit, it’s these subtle but personal alterations that ultimately deliver the desired result.

And once this process is approved, the automotive manufacturer will set up the vehicle to the tyre’s specification. The result? Superior suspension that works in harmony with the tyre, delivering a noticeably enhanced ride experience, outstanding handling characteristics, and punchier acceleration.

It’s undeniable. If you truly want to experience the original performance characteristics that your car is really capable of, investing in the right homolagated tyres is an absolute must.

Talk to Asda Tyres – your unrivalled tyre expert

Purchasing tyres can seem complicated, so if you’re still unsure of which tyres – homologated or otherwise – are right for your car, seek out the experienced, expert advice from Asda Tyres. Click here to live chat to one of our experts, or find your nearest fitting station.

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