SidewallRef

Sources

Every published value on this site was read from at least two independent sources. Here is the whole list, the cells the sources disagreed on, and the values left out because two could not be found.

Sources
26
Disagreements
5
Stated gaps
9

The three rules

  1. No row from a single source. Every published row carries at least two independent sources. A value found in only one place was left out and the gap is stated.
  2. A disagreement is reported, not resolved in silence. Where two sources gave different figures, both are printed with an assessment of which was stored and why.
  3. A computed number is never presented as a published one. Diameter, revolutions per mile and speedometer error are worked out here, and every one of them prints its formula.

These are independent publishers, not independent measurements. Each one reproduces a table originally set by a standards body, so agreement between them shows a value was transcribed correctly, not that the underlying table is right. Where a figure is safety relevant, check it against the tire manufacturer's own data before relying on it.

Load index table

151 rows, index 0 to 150 · 5 sources

  • Tyre Load Index Chart (LI 0-150) - AmesWeb, states ETRTO and SAE tables as the basis (read 2026-08-27)
    Load index 0 to 150, kilograms
  • Tire Load Rating Chart - Your Auto Vision, page dated 21 April 2026 (read 2026-08-27)
    Load index 0 to 150, kilograms and pounds; load range letters
  • Load Index - CJ Tire, cites ETRTO Standards Manual 2010 page G7, standard load table at 42 psi (290 kPa) (read 2026-08-27)
    Load index 60 to 124, kilograms and pounds
  • Load Index & Weight Ratings - rimlist, undated reference article (read 2026-08-27)
    Load index 80 to 121, kilograms and pounds; load range letters; SL, XL and HL reference pressures
  • How to Read Speed Rating, Load Index and Service Descriptions - HP Wizard, reproduces Tire Rack tire tech information (read 2026-08-27)
    Load index 71 to 90, kilograms and pounds; speed symbols L to Y; ZR and bracketed symbols

Load index 27: 97.5 kg (LI-AMESWEB) against 97 kg (LI-AUTOVISION). Indices 20 to 28 rise in an exact 2.5 kg step in both tables, which 97.5 continues and 97 breaks. The 97.5 reading is stored and the alternative is printed alongside it.

Speed symbol table

30 symbols, A1 to (Y) · 8 sources

Symbol P, miles per hour: 94 mph (SR-CJTIRE) against 93 mph (SR-TIREGUIDE). 150 km/h converts to 93.21 mph. CJ Tire rounds up; the six other tables here that print an mph column round to nearest. Every source agrees the defined value is 150 km/h, so this site stores 150 km/h and derives 93 mph.

Symbol Q, miles per hour: 100 mph (SR-CJTIRE) against 99 mph (SR-TIREGUIDE). 160 km/h converts to 99.42 mph. Same rounding difference as symbol P, and the same resolution: the km/h figure is what the symbol is defined by, and the six other mph columns print 99.

Symbol Y, kilometres per hour: not printed (the cell reads N/A) (SR-CJTIRE) against 300 km/h (SR-AMESWEB). CJ Tire's chart leaves the km/h cell for Y blank while printing 186 mph next to it. Seven other tables print 300 km/h, and 186 mph is the conversion of 300 km/h, so this is a gap in one table rather than a competing figure.

Left out on purpose

  • (W), a tire tested above 270 km/h, is listed by one of the eight sources consulted (CJ Tire) and by none of the other seven. One source is not enough to publish a safety-relevant figure, so it has no row here. The general rule about brackets above still applies to it, and five sources state that rule.
  • Z on its own, without a following R, appears in older tables as a rating above 240 km/h. It is covered as a note under ZR rather than as a row, because the sources describe it as superseded rather than as a current published symbol.
  • Symbols above (Y) are not published. A tire faster than that carries a manufacturer's own statement of its maximum, not a standard symbol.

Sidewall markings

DOT code, UTQG grades, load range letters, winter symbols · 12 sources

  • 49 CFR 575.104 - Uniform tire quality grading standards - Legal Information Institute, Cornell Law School, current text read 27 August 2026 (read 2026-08-27)
    Traction grade adhesion coefficients, traction and temperature grade definitions, treadwear grading procedure
  • Uniform Tire Quality Grading - Wikipedia, revision read 27 August 2026 (read 2026-08-27)
    Traction grade g force table, temperature grade speeds, treadwear grade meaning and limits
  • UTQG Ratings Explained - TireGrades, updated 9 March 2026 (read 2026-08-27)
    Traction grade g force table, temperature grade speeds, treadwear self reporting
  • UTQG - How to Read a Sidewall - Yokohama Tire, undated manufacturer reference (read 2026-08-27)
    Temperature grade speeds, which tire categories are exempt from UTQG marking
  • Understanding DOT Codes: Guide to Tire Identification - Wheel-Size.com, undated reference article (read 2026-08-27)
    DOT code structure, plant code width, omitted letters, date code format and which sidewall carries it
  • 5 Tips to Read the DOT Date Code - Tires Easy, undated reference article (read 2026-08-27)
    DOT date code format before and after 2000, worked examples
  • Tire code - Wikipedia, revision read 27 August 2026 (read 2026-08-27)
    Load range letters and ply ratings, M+S definition, sidewall marking glossary
  • Load Range - CJ Tire, undated reference chart (read 2026-08-27)
    Load range letters A to N with ply rating equivalents
  • Tire Load Ranges: Complete Guide (B Through F) - TireGrades, updated 24 June 2026 (read 2026-08-27)
    Load range letters B to F with ply ratings and maximum inflation pressures
  • Tire Load Rating Chart - Your Auto Vision, page dated 21 April 2026 (read 2026-08-27)
    Load range letters B to G with ply ratings and maximum inflation pressures
  • What the 3PMSF Symbol Means for Winter Driving Safety - Les Schwab, undated reference article (read 2026-08-27)
    3PMSF meaning, the medium packed snow test, what the symbol does not cover
  • What Is the 3PMSF Symbol and How Does It Affect Your Tires - DuallyWheels, undated reference article (read 2026-08-27)
    3PMSF test standard and the 110 percent traction index threshold, M+S comparison

Left out on purpose

  • Maximum inflation pressure for load ranges A and G through N. Fewer than two of the sources consulted published a figure. Of the charts that do publish one for G, the source consulted here gives 105 psi while other charts in circulation give 110 psi, so nothing is published for it.
  • DOT plant code lookup. Plant codes are assigned and revised by the federal regulator and the published lists in circulation are incomplete and out of date; a partial list here would be worse than none.
  • The DOT size code and type code are manufacturer-assigned and not standardised, so they cannot be decoded from a table at all.

Service types and construction

6 prefixes, 3 construction letters, 4 reinforcement designations · 5 sources

Whether Euro-metric tires take the 1.10 light truck derating: yes - the bulletin's heading and text both read 'P-metric or metric tire' (ST-NITTO) against yes - 'When P-metric or metric tire are installed on light trucks' (ST-NEXEN). Retail and forum sources are split, with several stating that the derating applies to P-metric only. Both tire manufacturer technical bulletins consulted state it applies to metric (Euro-metric, also called hard metric) as well, and both attribute the rule to federal motor vehicle safety standards. This site follows the two manufacturer bulletins and flags the split, because the conservative reading is also the one the primary-facing documents give.

Left out on purpose

  • The Light Load (LL) reference pressure appears in only one of the sources consulted, so no pressure is published for it.
  • The High Load (HL) reference pressure appears in only one of the sources consulted, so no pressure is published for it. The designation itself is confirmed by two.

Size catalog

879 sizes · 2 sources

  • Published tire size sitemap - SimpleTire, sitemap dated 13 August 2026 (read 2026-08-27)
    Which sizes a national retailer publishes a catalog page for
  • Published tire size listing sitemap - Discount Tire, sitemap read 27 August 2026 (read 2026-08-27)
    Which sizes a second national retailer publishes a catalog page for

Left out on purpose

  • This says a size is sold. It does not say the size fits any particular vehicle, that it exists in the load index that vehicle needs, or that a wheel exists in the offset required. Those are questions for the vehicle placard and a fitter.

How the size catalog was chosen

A size gets a page here only when both retailers above publish a page for it. Sizes listed by one and not the other were left out, so a size shown here is one two independent national catalogs agree exists.

This says a size is sold. It does not say the size fits any particular vehicle, that it exists in the load index that vehicle needs, or that a wheel exists in the offset required. Those are questions for the vehicle placard and a fitter.

Found something wrong?

A reference is only as good as its corrections. If a figure here disagrees with a source you trust, email socialreminderinfo@gmail.com with the page and the source, and it will be checked against the sources listed above.