Tractor Tyre Sizes and Sidewall Markings: An Indian Buyer’s Replacement Guide

A request for “a 28-inch tractor tyre” leaves most of the purchase undecided. It does not identify section width, construction, tread pattern, load capability or an approved front-to-rear combination. Before comparing rupee prices, copy the complete markings and establish the fitment required by your tractor's manual. A tyre that fits the rim diameter can still be the wrong replacement.

This guide helps Indian owners prepare a replacement order and compare quotations. It is not a universal tyre-conversion chart, an inflation prescription or permission to change the manufacturer's approved fitment. The examples explain notation; they do not recommend those sizes for a particular tractor.

Read an imperial size without losing the units

In a conventional size such as 13.6-28, the first number denotes nominal section width in inches and the final number denotes rim diameter in inches. The dash is commonly used for bias construction. The final 28 is not the tyre's overall outside diameter, and 13.6 is not the rim width.

Keep the complete designation when requesting a quotation. Writing only “28 rear” removes the information needed to distinguish several very different products. Also record the tyre brand, product or tread name, construction and markings following the size. If an old sidewall is difficult to read, have the tyre professional identify it instead of guessing a missing digit from another tractor nearby.

Decode a metric example in three steps

Take 420/85R28 as a notation example:

• 420 is nominal section width in millimetres.
• 85 is the aspect ratio: nominal sidewall height as a percentage of section width.
• R denotes radial construction; 28 is rim diameter in inches.

The simple calculation 420 × 0.85 = 357 mm illustrates nominal sidewall height. It is not a measurement of loaded radius, clearance or rolling circumference. Do not build a replacement approval from that arithmetic. CEAT's size explanation distinguishes section width, profile and rim size; use the technical data for the exact proposed product when assessing real dimensions.

Do not confuse a ply rating with actual layers

A marking such as PR is a casing-strength rating, not a count of physical fabric layers. Likewise, a load-index number is a code to interpret with the manufacturer's data, not the load in kilograms written directly on the tyre. A speed symbol adds another condition; do not compare carrying capability while ignoring the specified speed and pressure.

CEAT's sidewall guide explains these markings, including TT for tube-type and TL for tubeless construction. That source is used for marking principles, not US fitment recommendations or prices. Ask the fitter to specify the compatible tyre, rim, tube or valve arrangement. A change from TT to TL is not settled by deleting the tube from the invoice.

Match ratings to the job, not only to the bonnet badge

The tractor model and axle configuration belong on the enquiry, but horsepower alone does not determine a tyre's load requirement. Describe the real working setup: mounted equipment, carried material, ballast and road travel. Ask the supplier which load and speed data apply to that setup, rather than selecting a product simply because its PR or load-index code is numerically larger.

CEAT India explains load and speed ratings. The practical buying lesson is to request the applicable rating information in the same quotation as the size and pattern. If a seller cannot identify the exact product specification, a lower price does not resolve that missing information.

A matching rim diameter is only the first fitment check

Confirm approved rim width as well as diameter, the proposed tyre's dimensional data and the tractor manufacturer's permitted fitment. Include clearance to fixed parts and the complete machine width. If a change affects access, use our route and width worksheet, while keeping tyre approval as a separate technical decision.

An imperial-to-metric label comparison does not itself prove interchangeability. Two products described as alternatives still need the correct rim, construction, dimensions and operating ratings checked. Avoid buying from an online conversion list alone, especially when the proposed product differs in tread or construction from the fitted tyre.

For 4WD, record the complete front-and-rear combination

A driven front axle makes the relationship between the front and rear tyres particularly important. CEAT India's fitment guidance warns that an unapproved size relationship can cause transmission wind-up. Matching rim diameter or approximate outside height is not an adequate substitute for the tractor manufacturer's approved combination.

Give the dealer the full front and rear product details, including the proposed replacements and the tyres that will remain. Ask for the applicable rolling-circumference data and manufacturer approval. If only one axle is being changed, do not assume the unchanged axle is irrelevant. We do not prescribe a universal lead percentage or approve mixing tyres from an arithmetic ratio alone.

Compare two hypothetical quotations

Suppose Offer A says “rear tractor tyre, 13.6-28” and gives one total. Offer B identifies the manufacturer, product pattern, complete size, construction, rating, tube or valve requirements and approved rim, with fitting and other charges separated. No actual dealer prices are implied by this example.

Offer B is easier to assess because it describes a product and scope. It is not automatically the correct or better-value purchase. First verify that specification against the tractor and work. Then ask Offer A's seller to fill the same entries. Compare totals only when both describe an approved equivalent scope, including whether the quote is for one tyre or a pair. A cheaper incomplete quotation is not evidence of a saving.

Take this replacement sheet to the supplier

• Tractor: full model, drive configuration and relevant manual or manufacturer fitment information.
• Existing tyres: axle, side, complete size, brand, pattern, construction and all rating markings.
• Proposed product: exact identity, approved rim specification and dimensional data.
• Working setup: mounted equipment, ballast, carried loads and expected road/field duties.
• Compatibility: applicable load/speed data and, for 4WD, approval of the complete axle combination.
• Installation scope: tyre quantity, compatible tube or valve where required, professional fitting and disposal arrangements.
• Rupee quotation: dated local offer with tax treatment, fitting, transport and any other charges clearly identified.
• Handover: supplied products match the order, written warranty terms and the correct operating-pressure information are provided.

Have mounting and fitment questions handled by a trained tyre professional. Do not copy a neighbour's pressure or treat a sidewall maximum as a universal working setting. Keep the confirmed specification and invoice so that the next replacement enquiry starts with the actual approved product rather than a partly remembered size.

Sources and editorial scope

The CEAT sources linked above were checked on 10 October 2026. The quotation comparison, enquiry sheet and 357 mm calculation are original explanatory examples, not field measurements or test results. This guide does not claim a fuel-saving percentage, publish a universal replacement-size table or assign an Indian-market price to an unidentified tyre.