How do I read the tyre size on the sidewall?

What does 205/55 R16 mean?

205 is the width in millimetres, 55 the sidewall height as a percentage of width, R means radial, 16 the rim diameter in inches. Read those elements together rather than treating each as a separate choice. The width describes the tyre's nominal section width, while the percentage describes its profile. The final part tells you which rim diameter the tyre is made to fit; it does not describe the wheel's overall outside diameter.

The profile figure is a proportion, not a sidewall measurement in millimetres. That means the same profile marking on tyres of different widths does not mean they have the same sidewall height. R describes construction, not radius, and the rim diameter must match the wheel. You do not need to calculate a replacement size yourself: copy the complete code, then compare it with the sizes approved for your particular car.

What do 91 and V mean?

91 is the load index and V the speed rating. These are separate from the dimensions, so two tyres with the same size can still have different load or speed ratings. The load index refers to a standardised carrying-capacity category, rather than a weight printed directly in the code. The speed letter identifies a rated speed category under specified conditions; it is not advice about how fast you should drive.

You should check both ratings against the vehicle manufacturer's requirements instead of assuming any tyre with matching dimensions will do. Ask the shop to confirm the required load index and speed rating from the manual or vehicle information. If a seller proposes a different rating, have them explain its suitability before you approve the purchase. A higher-looking number or a different letter does not, by itself, establish that the complete tyre is right for your car.

Where do you find the size your car actually needs?

The car's approved sizes are on a label in the door frame, fuel flap or the manual. Start there, because the sidewall only tells you what is fitted now. A previous owner may have changed the wheels or installed an unsuitable tyre. This is especially worth checking when you buy an imported used car in Georgia and do not know its maintenance or modification history. Match the information to your exact vehicle rather than a similar-looking model.

Read any conditions attached to the approved sizes, including whether different sizes apply to the front and rear axles or to particular wheel options. If the label is missing, unreadable or inconsistent with the manual, ask a shop to verify the specification before ordering. A VIN can help identify the vehicle, but a recorded-history check does not replace confirmation of tyre fitment. Photograph the label and the existing sidewalls so you can show the shop exactly what you found.

• Find the vehicle label or the relevant manual page.
• Copy the full size and the required load and speed ratings.
• Compare the front and rear tyres separately.
• Tell the shop if the wheels have been changed.

Can you change the width, profile or rim size?

You should change tyre dimensions only after confirming that the proposed tyre and wheel combination is approved for your car. Changing one part of the code affects more than appearance: the tyre must fit its wheel and have suitable clearance on the vehicle. A tyre designed for a different rim diameter cannot be made suitable simply because its width looks close. Ask the shop to check the whole combination rather than choosing one marking in isolation.

Do not treat an online size comparison or a seller's assurance that a tyre is nearly the same as approval. Alternative fitments depend on the car, its wheels and any manufacturer conditions. Some vehicles have particular requirements for matching tyres across axles, so consult the manual before replacing only part of a set. If your car has an LPG/CNG conversion, do not guess a new load rating from that fact alone; ask the shop to check the vehicle's requirements.

What else should you check before buying?

You should check the tyre's condition, intended use and any additional manufacturer requirements as well as its size code. Matching 205/55 R16 does not tell you whether a particular tyre suits your season, route or vehicle. Tell the shop whether you mainly drive in Tbilisi traffic, travel on mountain roads or regularly carry passengers and luggage. Use that information to discuss suitable options, without assuming that a size marking alone describes grip or performance.

Keep tyre pressure separate from tyre size: the correct pressure comes from the vehicle's instructions for your load and use, not from decoding this example. Other sidewall markings may relate to manufacture, reinforcement, fitting direction or seasonal characteristics. Ask the shop to explain any unfamiliar marking that affects your choice. If you are buying used tyres, dimensions alone cannot establish their condition; have their suitability and condition checked rather than relying only on a photograph of the code.

• Check for visible cracks, cuts, bulges or other damage.
• Ask whether the tyre suits your intended driving conditions.
• Confirm any reinforced or vehicle-specific requirements.
• Use the vehicle's guidance for tyre pressure.

When should you ask a tyre shop for help?

Ask a tyre shop for help before buying if the markings are unclear, the fitted sizes disagree with the vehicle information, or you are considering different wheels. Also arrange a check if you notice damage, rubbing, vibration or repeated pressure loss; reading the code cannot diagnose those problems. If a tyre appears unsafe, avoid continuing to drive on it and seek assistance. Do not wait for periodic technical inspection to resolve a known tyre concern.

Send the shop a clear sidewall photo, the vehicle label and a description of what you need checked. On junto.ge/services, you can find car services by service, price, place and the next free time, then book a visit online; the shop confirms the booking. If the shop sends suggested work through Junto by SMS, you can review each line and its price before work starts. Ask for an explanation of the proposed tyre specification before approving any replacement.

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