How to Read Your Tyre Sidewall — A Dubai Driver's Complete Guide

The Main Size Code — What 225/55 R17 97W Means

This is the most visible marking, usually the largest text on the sidewall.

**225** — Section width in millimetres. The width of the tyre measured across the widest point of the sidewall at correct inflation. A wider tyre gives more road contact and grip. A narrower tyre reduces rolling resistance and fuel consumption.

**55** — Aspect ratio as a percentage. The sidewall height is 55 percent of the section width. So for a 225mm wide tyre: sidewall height = 225 x 0.55 = 123.75mm. A lower aspect ratio (35, 40, 45) means a lower, stiffer sidewall — common on performance and luxury vehicles. A higher aspect ratio (65, 70) means a taller sidewall with more cushioning — common on family SUVs.

**R** — Radial construction. All modern tyres are radial. The R indicates the internal cord layers run radially from bead to bead. You will never see a B (bias-ply) or D (diagonal) on a modern passenger vehicle tyre.

**17** — Rim diameter in inches. The tyre fits a 17-inch wheel. This must exactly match your wheel.

**97** — Load index. Each number maps to a maximum load capacity in kilograms. Load index 97 = 730kg per tyre. For a four-tyre vehicle, maximum load = 730 x 4 = 2,920kg. Never fit a tyre with a lower load index than specified for your vehicle. In Dubai, where vehicles are regularly loaded with passengers and luggage, load rating is particularly important.

**W** — Speed rating. W-rated tyres are approved for sustained speeds up to 270 km/h. Never fit a tyre with a lower speed rating than the vehicle's maximum speed. UAE speed limits are high and some vehicles are capable of very high speeds.

Speed Rating Chart for Dubai Drivers

For most Dubai family vehicles a minimum of H-rating is recommended. V and W are more appropriate for sedans and SUVs that routinely drive at 120 km/h plus. Performance vehicles and sports cars typically require W or Y minimum.

The DOT Code and Manufacturing Date

The DOT (Department of Transportation) marking is a critical code that most Dubai drivers do not know how to read.

It looks like: **DOT XXXX XXXX 1223**

The last four digits are the manufacturing date:

**Example:** DOT ending in **1223** means manufactured in the 12th week of 2023 — approximately March 2023.

**Why this matters in Dubai:**

RTA guidance and all major tyre manufacturers recommend replacing tyres older than 5 years in the UAE's high-heat climate, regardless of remaining tread depth. The rubber compounds degrade from heat even on tyres that are not driven on frequently. A tyre manufactured in 2019 is now over 7 years old. Even if the tread looks acceptable, the compound has undergone significant thermal degradation through multiple Dubai summers.

**What to check when buying used vehicles:**

Always check the DOT date on all four tyres before purchasing a used car in Dubai. Sellers often replace only the visually worn tyres while leaving old but deep-treaded tyres on the other positions. A tyre from 2019 on a used car is a safety concern even if the tread depth reads 6mm.

• First two digits: week of manufacture (01 to 52)
• Last two digits: year of manufacture

Run-Flat Markings

Run-flat tyres carry additional markings that identify them as capable of supporting the vehicle after complete pressure loss.

Common run-flat codes by manufacturer:

When replacing a run-flat tyre, always replace with a tyre carrying the same run-flat designation. Fitting a conventional tyre on a run-flat position without informing the technician is a safety issue — run-flat equipped vehicles often have no spare and may have TPMS systems calibrated for run-flat response times.

• **ROF** — Bridgestone Run-On-Flat
• **RFT** — Michelin Run-Flat Technology
• **SSR** — Continental Self-Supporting Runflat
• **ZP** — Michelin Zero Pressure
• *** (asterisk)** — BMW OE approved tyre (often run-flat)
• **MO** — Mercedes-Benz Original Equipment approved

Load Capacity Index Table for Dubai Reference

Common load indices on Dubai market vehicles:

Other Sidewall Markings

**M+S or M&S** — Mud and Snow designation. Not a winter tyre — simply indicates the tread pattern meets minimum all-season criteria. All-season tyres for Dubai are fine. Dedicated winter tyres are not needed.

**Rotation arrow** — Directional tyres have an arrow showing which direction the tyre must rotate when mounted. Fitting a directional tyre the wrong way eliminates the tyre's designed drainage channels and significantly reduces wet grip. In Dubai, where rainfall is rare but intense, this matters more than it might seem.

**Asymmetric marking (Outside / Inside)** — Asymmetric tyres have different inner and outer tread patterns. They must be fitted with the "Outside" marking facing outward. Fitting them reversed reduces grip and causes abnormal wear.

**Max Load and Max Pressure** — These are the absolute maximum values the tyre can handle in an emergency. They are not operating specifications. Do not inflate to the Max Pressure figure shown on the sidewall for normal driving.

**UTQG (Uniform Tyre Quality Grading)** — Three numbers covering Treadwear, Traction, and Temperature resistance. Example: 440 AA A means treadwear rating 440 (very long life), traction AA (excellent wet grip), temperature resistance A (highest). Higher treadwear numbers mean longer tyre life. In Dubai's high-heat conditions, a tyre with a high temperature resistance rating (A) is preferable to one rated C.

How to Check If a Tyre Is Correct for Your Vehicle

**Step 1:** Find the recommended tyre size on your door jamb sticker (driver's side, inside the door frame).

**Step 2:** Compare the size code on the sidewall to the sticker specification.

**Step 3:** Check that the load index on the tyre meets or exceeds the minimum for your vehicle.

**Step 4:** Check that the speed rating meets or exceeds your vehicle's maximum speed.

**Step 5:** Check the DOT date — confirm the tyre was manufactured within the last 3 years for new tyres, and is within the last 5 years for any tyre on the vehicle.

If any of these checks fail, the tyre is not correct for your vehicle.