The direct answer: An OE marking (Original Equipment) is a small symbol or abbreviation on the tire sidewall – for example, a star (*), MO, AO, or N0 – used by a vehicle manufacturer to indicate that this specific type of tire has been specially tested and tuned for a particular model. This is also known as tire approval. Important for the purchasing decision: An OE marking is not a legal requirement. It is a voluntary manufacturer recommendation for optimal tuning – not an approval criterion like a wheel certificate. This guide clarifies what the marking means, which abbreviations exist, where you can find them, and what to do if your desired tire does not have the appropriate approval. Legal status and review date: August 2026, Germany.
1. What exactly is tire approval (OE marking)?
When a car manufacturer develops a new model, they test not only their own components but also the tires with which the vehicle is supplied ex works or as a recommended retrofit option. If a certain tire model in a certain dimension passes this test series, the manufacturer assigns its own marking, which the tire manufacturer then molds or embosses into the sidewall. This marking is essentially an approval: "This tire meets our requirements for this model."
It is important to distinguish between two terms that are often confused:
- Standard tires (original equipment): the tires with which the vehicle leaves the factory.
- OE-approved retrofit tires: tire models that the manufacturer has subsequently tested and approved for the model, even if they were not necessarily fitted ex works.
Both bear the same marking on the sidewall. For you as a buyer, this means: A tire with a suitable OE marking is demonstrably tuned to your vehicle model – regardless of whether it was installed ex works or approved later.
Note: OE marking is not the same as tire size, load index, or speed rating. These three values are independent, vehicle-specific mandatory specifications from the vehicle registration document and must match for every tire – with or without an OE marking. The guide Reading Tire Size & Tire Designation explains how to read these values on the tire sidewall.
2. Why do car manufacturers assign OE markings at all?
From the manufacturer's perspective, approval is a quality assurance instrument. Three reasons are particularly important:
Acoustic Tuning
Tires are one of the main sources of rolling noise in the interior. Manufacturers specifically tune the tread geometry and internal structure of the tire to the bodywork so that interference frequencies do not overlap with the vehicle's acoustics. Some premium manufacturers also use a foam core inside the tire to dampen resonances – this is also part of the individual tuning and is usually recognizable by its own additional marking.
Suspension Behavior and Chassis Tuning
A tire is mechanically part of the chassis. Sidewall stiffness, carcass construction, and damping behavior interact directly with the springs and dampers. A manufacturer tunes its chassis to a specific tire behavior – a tire with significantly different sidewall stiffness can noticeably change driving behavior and responsiveness, without automatically becoming unsafe.
Specific Rubber Compound
The rubber compound simultaneously influences rolling resistance, wet grip, and wear – and these three properties are technically in competition with each other. For OE approval, the tire manufacturer specifically tunes the compound to the weight, engine, and target profile of the respective vehicle model, instead of using a general standard compound.
These three points explain why approval is model- and often even engine-specific: The same type of tire can be approved for one vehicle variant and not for another variant of the same model.
3. Overview of the Most Important OE Markings
Each vehicle manufacturer uses its own abbreviation system. There is no uniform, manufacturer-neutral standard for this – the following table shows the most common markings found in Germany on premium manufacturers:
| Manufacturer | Marking | Meaning / Note |
|---|---|---|
| BMW | * (Star) | Standard marking for BMW-approved tires; sometimes with an addition for runflat variants |
| Mercedes-Benz | MO, MO1 | MO stands for "Mercedes Original"; MO1 indicates a revised or updated approval generation of the same tire |
| Audi | AO | Audi Original approval; analogous to MO for Mercedes-Benz |
| Porsche | N0 to N5 | Continuous generation marking; a higher number means a newer approval generation, not automatically a "better" tire |
| Jaguar / Land Rover | J | Group-specific approval marking for both brands |
Other manufacturers have their own, sometimes brand-specific systems, which are deliberately not listed here to avoid making uncertain statements – if in doubt, check directly with the vehicle manufacturer or in the vehicle manual whether and which marking is relevant for your model. For many volume manufacturers, there is no visible OE marking on the tire sidewall; approval is done exclusively internally via approval lists, without being readable on the tire itself.
Note: A higher or newer marking generation is not a quality judgment. N3 is not "worse" than N5 – the number only indicates which model year or revision the approval belongs to. What matters is which marking is intended by the manufacturer for your specific vehicle and year of manufacture.
4. Is Tire Approval Legally Required?
There is a lot of uncertainty here – so let's clearly separate regulations from recommendations.
What is Mandatory
An OE marking is not a legal registration requirement in Germany. There is no regulation stating that a tire without a manufacturer's own abbreviation like MO, AO, or a star may not be driven. Instead, other vehicle-specific details are legally binding: the tire size, load index, and speed rating entered in the vehicle registration document must at least correspond to the registered values. These are independent, mandatory criteria – regardless of whether the selected tire also bears an OE marking or not.
This fundamentally distinguishes tire approval from wheel approval: For wheels, a registered parts certificate or EC type approval determines whether a combination is permissible without individual approval – as explained in the guide on the KBA number for wheels and in the guide on how to successfully register wheels with the TÜV. For tires, this formal approval procedure does not exist in this form: a technically suitable, correctly dimensioned tire without an OE marking is permissible without further ado.
What is a Recommendation
The OE marking remains useful nevertheless – but as a quality recommendation, not a requirement. Vehicle manufacturers often point out in manuals that approved tires are optimally tuned for the respective model, especially for vehicles with a sporty orientation, runflat technology, or a particularly comfort-oriented chassis tuning. Those who consciously want to benefit from this comfort and tuning advantage choose a tire with a suitable marking. Those who primarily value technically correct, safe, and more affordable tires can generally opt for a tire without an OE marking if the mandatory values are correct.
Note: Legal classifications can change. The status described here is August 2026 for Germany. If in doubt, always check the current information in the vehicle registration document, the vehicle manual, or with an officially recognized inspection body. This article does not replace legal advice.
5. Where Can You Find the OE Marking on the Tire?
The marking – just like size, load index, and DOT number – is located directly on the tire sidewall, usually at the end of the tire designation, often in close proximity to the manufacturer's designation of the tire model. It is small and easily overlooked because it stands between other blocks of numbers and letters. Here's the quickest way to find it:
- Clean the tire sidewall. Brake dust and dirt make small embossments practically unreadable – a damp cloth usually suffices.
- Read the complete tire designation. Directly after the size specification and the load index/speed rating, the OE marking usually follows, if present.
- Check both sides of the vehicle. For some tire models, the complete marking is only on one sidewall – similar to the date code, which the guide Tire Age & DOT Number explains in detail.
- If in doubt, use manufacturer specifications. If the marking is not clearly legible, the vehicle manufacturer or tire dealer can help with model and year of manufacture information.
If you don't find any marking at all, it doesn't automatically mean that the tire doesn't fit – it merely means that either no visible OE marking exists for this model, or the respective tire type is simply not part of the vehicle manufacturer's approval list.
6. What to do if your desired tire does not have a suitable approval?
This situation is common in everyday life: the tire that fits in terms of price, size, or reviews does not have an OE marking for your vehicle. Three points help with the decision:
- Check mandatory criteria first. Size, load index, and speed rating must correspond to the entries in the vehicle registration document – regardless of the OE marking. This is the actual safety and approval standard. The guide Vehicle Registration Document Explained shows where to find these values in the vehicle registration document.
- Honestly assess your usage profile. Those who drive long distances at high speeds and expect maximum rolling comfort will benefit more from a suitable OE approval. Those who primarily value a solid price-performance ratio for everyday driving can confidently choose a tire without a marking if the mandatory values are correct.
- Seek expert advice if unsure. A tire specialist can assess, based on model, year of manufacture, and equipment, whether a relevant marking exists for your vehicle at all and how much this affects comfort and acoustics.
A common misconception should be clarified at this point: A tire without an OE marking is not less safe or of lower quality than an approved tire. It is merely not individually optimized for a specific vehicle model. Safety, wet grip, and braking behavior primarily depend on the general tire quality, tread depth, and age – not on the existence of a manufacturer's abbreviation.
7. zrshop Tire Brands at a Glance: Berlin Tires and Syron
Transparency is part of this topic: In the ZR Shop, we carry two of our own tire brands in the price-conscious value segment: Berlin Tires and Syron. These brands do not advertise with vehicle manufacturer OE markings, and we cannot make any statement at this point about whether and for which vehicle models approvals exist – therefore, we deliberately do not claim that here.
What this means for the purchasing decision: Those who are specifically looking for a tire with a suitable OE marking for vehicles from manufacturers such as BMW, Mercedes-Benz, Audi, Porsche, or Jaguar/Land Rover should consult the approval list of the respective vehicle manufacturer and look for premium tires with the corresponding marking. Those who are looking for a solid, technically correct spare tire without the claim of manufacturer-specific fine-tuning, however, will find an option in Berlin Tires and Syron for everyday use – regardless of the vehicle brand, as long as size, load index, and speed rating fit.
The concept of "OE marking" remains relevant to understand for every tire purchase – even if you ultimately consciously decide for a tire without this marking. It helps you to correctly classify the advertising claims and product descriptions of different brands, instead of incorrectly interpreting a missing marking as a defect.
8. OE Marking: Short Checklist for Purchase
| Question | Why Important |
|---|---|
| Do size, load index, and speed rating match the vehicle registration document? | Mandatory criterion, regardless of the OE marking |
| Does a visible OE marking exist for your vehicle model at all? | Not every manufacturer marks approvals on the sidewall |
| Is acoustic and chassis fine-tuning important to you, or is solid everyday usability paramount? | Determines how much the OE marking should influence your choice |
| Does the tire age (DOT) fit the purchase? | Independent quality criterion, see separate guide |
These four points are sufficient for most purchasing decisions. The OE marking is an additional criterion for fine-tuning – the first two lines of the table are the actual mandatory criteria.
FAQ: Tire Approval and OE Marking
What does the star (*) on a tire mean?
The star is BMW's OE marking. It indicates that this tire type in this dimension has been tested and approved by BMW for certain models – often in conjunction with runflat technology.
What does MO mean on a tire?
MO stands for "Mercedes Original" and is Mercedes-Benz's OE marking. MO1 indicates an updated or revised approval generation of the same tire model.
Is tire approval (OE marking) mandatory in Germany?
No. An OE marking is not a legal registration requirement, but a voluntary manufacturer recommendation for optimal tuning. Instead, the tire size, load index, and speed rating entered in the vehicle registration document are mandatory. Status: August 2026.
Can I drive tires without an OE marking?
Yes, provided that size, load index, and speed rating correspond to the entries in the vehicle registration document. A tire without an OE marking is not less safe – it is merely not individually tuned to a specific vehicle model.
Where can I find the OE marking on my tire?
On the tire sidewall, usually directly after the tire size and the load index/speed rating. The marking is small and can easily be overlooked on heavily soiled tires.
Does zrshop carry tires with OE approval?
In the ZR Shop, we carry two of our own tire brands in the value segment, Berlin Tires and Syron. For these brands, we make no statement about manufacturer-specific OE approvals. Size, load index, and speed rating according to the vehicle registration document remain decisive for suitability in any case.
Conclusion and Next Steps
An OE marking like *, MO, AO, N0 to N5, or J indicates that a tire type has been individually tuned by the vehicle manufacturer for acoustics, suspension behavior, and rubber compound to a specific model. This is useful, but voluntary additional information – not a legal requirement as with wheel registration. Tire size, load index, and speed rating according to the vehicle registration document remain crucial for approval and safety. Whether you choose a tire with or without a suitable OE marking ultimately depends on your demands for fine-tuning and your budget.
In the ZR Shop, you will find the complete tire assortment, including our own brands Berlin Tires and Syron. The guide Reading Tire Size & Tire Designation explains how to determine the correct size for your vehicle; you can find the appropriate load capacity in the Load Index Table.
Discover Tires in the ZR Shop →
Related topics
Sources and Status
- Information from vehicle manufacturers (BMW, Mercedes-Benz, Audi, Porsche, Jaguar/Land Rover) on OE tire approvals and associated markings – manufacturer information, interest-driven; the currently valid approval list of the manufacturer is authoritative
- Vehicle registration certificate (registration certificate part I) – binding entry of tire size, load index, and speed index
- Fundamentals of tire technology – relationship between rubber compound, rolling resistance, wet grip, and wear, as well as interaction between tires and chassis tuning
Note: Legal status and review date: August 2026, Germany. Information on approvals and markings may change and vary depending on the vehicle manufacturer, model, and year of manufacture. This article does not replace legal advice or individual manufacturer information.