When it comes to OE tyres, many manufacturers use their own codes of approval. This is something that many drivers don’t always understand, so let’s explore some of the more popular terms.

What does OE mean for cars?

When it comes to approved tyres, OE stands for Original Equipment. This refers to products that will be installed on a new vehicle when it is shipped from the plant. These are also known as approved tyres, as they undergo several months of testing to certify the tyre size and dimensions, durability, braking capabilities, noise level and other important parameters.

Car on road in motionWhat does OE stand for on cars?

In other cases, they may even be an entirely new product, created for a specific car. In either case, such tyres need to be approved by the vehicle manufacturer, which explains the term.

What is the difference between approved and unapproved tyres?

Approved tyres often have an original, unique tread pattern, as well as a different rubber compound mixture, designed to achieve the required hardness levels. They may also have a unique internal construction to ensure the required amount of stiffness.

Close-up of new tyres

Why do OE tyres have different properties?

The performance and comfort of the tyre can be directly linked to the general driver’s satisfaction with a given vehicle. Because of this, original equipment tyres play a vital role in achieving the required level of comfort and high performance. For new vehicles, it’s important that the car feels comfortable from the start, setting the standard that the driver will come to expect.

More specifically, when it comes to OE tyres, there are three approval groups:

  • The mandatory group. This covers tyres that cannot be installed on any car make other than the one it is approved for.
  • The technical group. These tyres can be installed on other vehicles but have certain reservations specified by the tyre manufacturer.
  • The free approval group, This refers to tyres that are fitted as original equipment but, outside of this, have no restrictions or limitations on which other vehicles they can be fitted to.

OE tyres can, yet don’t have to, have an approval for a given car. An approved tyre has a separate mark on its sidewall to indicate its status. A list of such symbols and meanings has been provided at the end of this article.

What should I do when I damage an approved tyre?

If you damage your tyres, you should buy replacement tyres, sticking to the exact same tyre model if they are approved. Otherwise, you should check the car manual to check if using unapproved tyres is possible.

However, if the manual is not clear on this, you should directly consult with your car’s manufacturer for a definitive answer.

How are tyres approved?

Each car manufacturer specifies the areas that, according to them, contribute to the driver’s satisfaction. Any changes of the tyre characteristics can greatly change the overall experience.

Below, you can find a chart that represents some of the various properties different tyres can have. One vehicle manufacturer, for example, might want to focus on a durable and quiet tyre, while another might prefer a sporty tyre for better grip and resistance to aquaplaning.

Parameters of dedicated tyres

Only the cooperation between car and tyre manufacturers on producing OE tyres can determine what external and internal construction characteristics can provide the best performance.

Approved tyre codes

Here you will find the markings used on approved tyres and what they indicate.

B – tyres for Audi (S3, S4, TT, TT Roadster), Bentley – installed in pairs on the same axle, can be installed on other makes
C1 - Pilot Sport tyres for Chrysler Viper GTS Coupe - cannot be installed on different makes
G1 - a tyre with a larger external diameter; can be mixed with other tyres only when installed in pairs on the same axle (Mercedes: S, CLK, C, SLK, SL Classes – rear axle, Alfa Romeo: 166, Fiat Stilo, Renault Laguna, Vel Satis), can be installed on other makes
K1 - approved for Ferrari - cannot be installed on other makes
M0 – approved for Mercedes - cannot be installed on other makes
N0…N3 – approved for Porsche, cannot be installed on other makes
R1 – a special CXKA tread – a single tyre approved for Audi
    * - approved for BMW

J – original equipment in Jaguar
N0, N1, N2, N3 – approved for Porsche
AO – approved for Audi
RO1 - approved for Audi models R and S
MO - original equipment in special versions of Mercedes Benz (e.g.:AMG) and Maybach
* - original equipment in BMW
M3 – original equipment in M class BMW
    E - optimised rolling friction as required by original equipment

(...) - approved for factory installation
A - American version of Scorpion STR
M0 - approved for Mercedes
N1...N3 - approved for Porsche
(*) - approved for BMW