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TYRES / WHEELS / GUIDESDE / EN

27 articles

Sizes & markings

Sidewall markings, the EU label and the details in vehicle documents.

Tyre code 205/55 R16 91V broken into width, aspect ratio, construction, rim, load and speed

Sizes & markings

Reading 205/55 R16 91V

The sequence combines dimensions, construction and service ratings. Keep it complete when buying.

Tyre cross-section with a dimension line across a nominal section width of 205 millimetres

Sizes & markings

What tyre width describes

The first number describes nominal section width, not simply the visible tread.

Tyre sidewall displaying the size 185/65 R15

Sizes & markings

Aspect ratio: why 55 is not millimetres

An aspect ratio becomes a calculated height only when combined with width.

Size designation on a mounted tyre sidewall

Sizes & markings

Matching tyre and rim diameter

Tyre diameter must match the wheel exactly; similar numbers do not provide fitting flexibility.

Schematic radial carcass cord direction and the letter R in a tyre size

Sizes & markings

The R in a tyre size

Within the size marking, R means radial construction rather than radius or width.

Tyre and example marking highlighting load index 91, corresponding to 615 kilograms per tyre

Sizes & markings

Understanding the load index

The number after the size is a table code, not a weight written directly in kilograms.

Example speed marking with a comparison of the H, V and W ratings

Sizes & markings

Speed rating and vehicle approval

A speed rating describes technical capability, not the permitted speed on a road.

Schematic XL marking beside a tyre and the checks for load, pressure and approval

Sizes & markings

XL tyres and their load capacity

XL identifies an increased load version within a size, not extra permitted vehicle payload.

HL highlighted as a prefix to an illustrative tyre size, with size, load and approval checks below

Sizes & markings

What HL means on a tyre

HL identifies a particular higher-load requirement and is not freely interchangeable with XL.

Two separate schematic vehicles illustrating C and CP tyre markings

Sizes & markings

Distinguishing C and CP tyres

C and CP identify different applications; vehicle documents determine the appropriate replacement.

Annotated photograph identifying the DOT date group 3511

Sizes & markings

Finding a tyre manufacture date

Four digits identify production week and year, but not the complete service history.

Three mountain peaks containing a snowflake, illustrating the Alpine marking

Sizes & markings

Recognising the Alpine symbol

The mountain-and-snowflake symbol is a defined marking, not generic winter artwork.

M+S lettering and a mountain-and-snowflake marking on a tyre sidewall

Sizes & markings

M+S is not the same as Alpine

M+S lettering and the Alpine symbol do not carry identical meaning.

Sizes & markings

Following the rotation arrow

The sidewall arrow identifies the intended rotation when travelling forwards.

Schematic wheel with an Outside marking and a cross-section distinguishing inner and outer sides

Sizes & markings

Inside and Outside when fitting tyres

On asymmetric tyres, the marking identifies the sidewall intended to face outwards.

Goodyear tyre tread showing small wear bars within the grooves

Sizes & markings

Finding TWI marks and wear bars

TWI marks help locate tread-wear indicators, but do not replace a complete condition check.

Schematic E approval mark with placeholders instead of an actual approval number

Sizes & markings

Understanding the E approval mark

An approval marking is neither a manufacturing-origin statement nor a tyre-quality ranking.

Two tyre cross-sections showing a tubeless construction and a separate inner tube

Sizes & markings

Tubeless tyres and tube-type tyres

Tubeless means operation without a separate inner tube, not immunity to pressure loss.

Tyre Max Pressure marking without a numerical value, distinguished from the vehicle inflation target

Sizes & markings

Maximum pressure is not the vehicle target

The sidewall maximum is not your vehicle’s routine inflation target.

Sizes & markings

Max Load on the tyre sidewall

Max Load describes a tyre capacity under conditions, not the car’s payload allowance.

Simplified A-to-E scale and the three label topics of rolling resistance, wet grip and external noise

Sizes & markings

Reading the EU tyre label

The label brings together several comparable properties, but is not a complete tyre assessment.

Flow diagram from the QR area of a tyre label to EPREL and checking product identity and size

Sizes & markings

QR codes and EPREL when buying tyres

The QR code leads to a product record; the key question is whether it matches the offered version.

Diagram of the logarithmic external-noise scale

Sizes & markings

Decibels and noise classes on the label

The noise figure describes rolling sound outside the car. It is only part of the picture when you want a quiet cabin.

Snow and ice testing shown as distinct criteria

Sizes & markings

Snow and ice symbols on the tyre label

The two winter pictograms refer to different tests. An ice symbol is not a universal upgrade for every winter tyre.

Illustrative front and rear tyre fields, not an official document

Sizes & markings

Tyre sizes in vehicle documents

The registration document is the starting point. Additional approved combinations may appear in other vehicle-specific paperwork.

Schematic link between CoC, vehicle variant and complete wheel combinations

Sizes & markings

Finding additional sizes in the CoC

The CoC may contain additional wheel-and-tyre combinations. It must match the vehicle variant and be read as a complete document.

Geometric circumference calculation explicitly distinguished from approval

Sizes & markings

Calculating rolling circumference: the limits

Geometry can explain differences between sizes. It cannot replace approval or checks on the vehicle.