Reference guides, data tables, and original engine-based TireFitLab studies. https://tirefitlab.com/learn/ 2026-06-23T00:00:00Z TireFitLab https://tirefitlab.com/learn/plus-sizing-study/ 2026-06-23T00:00:00Z

Original TireFitLab study of plus/minus tire-sizing candidates computed from the same engine as the live calculator.

https://tirefitlab.com/learn/plus-sizing/ 2026-06-23T00:00:00Z

What is plus sizing? How to go from plus 0 to plus one or plus two with a larger rim and lower-profile tire.

https://tirefitlab.com/learn/how-to-read-tire-size/ 2026-06-23T00:00:00Z

How to read a tire size: decode every number and letter in P205/55R16 91V — width, aspect ratio, rim diameter, load index, speed rating.

https://tirefitlab.com/learn/load-index/ 2026-06-23T00:00:00Z

Use the tire load index chart to convert ratings 60–130 into kg and lb, then verify the vehicle placard and axle-load requirements.

https://tirefitlab.com/learn/speed-rating/ 2026-06-23T00:00:00Z

Use the tire speed rating chart to convert symbols from L to Y/ZR into km/h and mph for replacement tyre checks.

https://tirefitlab.com/learn/bolt-pattern/ 2026-06-23T00:00:00Z

Find which bolt pattern your car uses and which wheels are compatible. PCD tables for 4x100, 5x112, 5x114.3 and more.

https://tirefitlab.com/learn/rim/ 2026-06-23T00:00:00Z

Find which tire sizes fit each rim diameter from 14 to 22 inches.

https://tirefitlab.com/learn/section-width/ 2026-06-23T00:00:00Z

What does the first number in a tire size mean? Tire section widths from 165 to 305 mm explained with compatible sizes and rim widths.

https://tirefitlab.com/learn/aspect-ratio/ 2026-06-23T00:00:00Z

What does the aspect ratio (series) number mean in a tire size? 35, 40, 45, 50, 55, 60, 65, 70 explained with sidewall heights and popular sizes.

https://tirefitlab.com/learn/tire-pressure/ 2026-06-23T00:00:00Z

What PSI should your tires be? How to find the correct pressure, what the TPMS light means, effects of over- and under-inflation, and how temperature changes pressure.

https://tirefitlab.com/learn/tire-rotation/ 2026-06-23T00:00:00Z

How often should you rotate your tires? Recommended intervals, the best rotation patterns for FWD/RWD/AWD, and what happens if you skip it.

https://tirefitlab.com/learn/wheel-alignment/ 2026-06-23T00:00:00Z

What is wheel alignment? Camber, caster and toe explained, symptoms of misalignment, how often to align, and the difference between alignment and balancing.

https://tirefitlab.com/learn/tyre-puncture-repair/ 2026-06-23T00:00:00Z

Can you repair a nail in a tyre? Plug vs patch vs plug-patch, the repairable zone rule, what size object can be repaired, speed limits after repair, and when to replace instead.

https://tirefitlab.com/learn/wheel-balancing/ 2026-06-23T00:00:00Z

What is wheel balancing? Why wheels go out of balance, symptoms of imbalance, static vs dynamic balancing, when to balance (new tyres, impact, vibration), and what it costs.

https://tirefitlab.com/learn/tyre-storage/ 2026-06-23T00:00:00Z

How to store winter or summer tyres correctly. Best conditions, stacking vs hanging vs upright, recommended pressure, bags vs bare, and how long tyres can safely be stored.

https://tirefitlab.com/learn/aquaplaning/ 2026-06-23T00:00:00Z

What is aquaplaning (hydroplaning)? Why it happens, speed and tread-depth thresholds, how to prevent it, and the correct response when your car starts to hydroplane.

https://tirefitlab.com/learn/tyre-tread-patterns/ 2026-06-23T00:00:00Z

The four main tyre tread pattern types: directional, asymmetric, symmetric, and block — how each affects wet grip, noise, aquaplaning resistance, and correct fitment direction.

https://tirefitlab.com/learn/tpms/ 2026-06-23T00:00:00Z

How TPMS works: direct (pressure sensor in each wheel) vs indirect (ABS wheel-speed comparison), what the warning light means, when to reset, and what TPMS cannot detect.

https://tirefitlab.com/learn/ev-tyres/ 2026-06-23T00:00:00Z

What makes an EV tyre different: higher load from battery weight, torque-steer stress on tread, acoustic foam for road noise, and low rolling resistance for range.

https://tirefitlab.com/learn/winter-tyre-laws/ 2026-06-23T00:00:00Z

Country-by-country legal requirements for winter tyres: which countries mandate winter tyres by law, exact seasonal dates or conditions, minimum tread depth for winter use, qualifying tyre markings (3PMSF vs M+S), and fines for non-compliance.

https://tirefitlab.com/learn/ 2026-06-23T00:00:00Z

Reference tables and guides for tire and wheel specifications: load index, speed rating, bolt pattern, rim compatibility.

https://tirefitlab.com/learn/tire-types/ 2026-06-23T00:00:00Z

What do the letters in a tire size mean? P, LT, metric, radial (R) and flotation tire types explained.

https://tirefitlab.com/learn/wheel-offset/ 2026-06-23T00:00:00Z

What is wheel offset (ET)? Positive, negative and zero offset explained, with how to measure backspacing and choose the right ET for your vehicle.

https://tirefitlab.com/learn/tire-age/ 2026-06-23T00:00:00Z

How to find and decode the DOT date code on your tire sidewall to determine its manufacturing week and year, and when to replace old tires.

https://tirefitlab.com/learn/speedometer-error/ 2026-06-23T00:00:00Z

Why changing tire diameter causes speedometer error, how to calculate it, EU/US legal limits, and how to check if your new tires will pass.

https://tirefitlab.com/learn/tread-depth/ 2026-06-23T00:00:00Z

How deep should tire tread be? Legal minimums (1.6 mm / 2/32"), the penny and quarter test, and a depth-to-action chart from new to unsafe.

https://tirefitlab.com/learn/tire-seasons/ 2026-06-23T00:00:00Z

What is the difference between summer, all-season and winter tyres? Temperature thresholds, compound chemistry, legal requirements and when to swap.

https://tirefitlab.com/learn/run-flat-tyres/ 2026-06-23T00:00:00Z

What are run-flat tyres? How they work, when you can drive on a flat, speed/distance limits, repair rules, and whether to replace all four at once.

https://tirefitlab.com/learn/nitrogen-vs-air/ 2026-06-23T00:00:00Z

Nitrogen vs air in tyres: does nitrogen keep pressure more stable, reduce moisture, and extend tyre life? Science-based comparison — when it matters and when it does not.

https://tirefitlab.com/learn/winter-driving/ 2026-06-23T00:00:00Z

How to prepare your tyres for winter: winter vs all-season vs summer in cold weather, cold-pressure drop, stopping distance data, snow chain rules, and ice driving technique.

https://tirefitlab.com/learn/tyre-noise/ 2026-06-23T00:00:00Z

Why tyres make noise: tread-pattern hum, road surface resonance, cupping, and cavity noise. How to identify which tyre is loud and what to do about it.

https://tirefitlab.com/learn/tyre-sidewall-damage/ 2026-06-23T00:00:00Z

Tyre sidewall damage explained: bulges, cracks, cuts, and scrapes — which are safe, which require immediate replacement, and how to tell the difference.

https://tirefitlab.com/learn/eu-tyre-label/ 2026-06-23T00:00:00Z

How to read the EU tyre label: fuel efficiency grades A–E, wet braking grades A–E, exterior noise in dB and 1–3 waves, and what each rating means for real-world driving.

https://tirefitlab.com/learn/tyre-load-capacity/ 2026-06-23T00:00:00Z

How tyre load capacity works: the load index table, how inflation pressure affects load carrying ability, single vs dual fitment ratings, and why overloading is dangerous.

https://tirefitlab.com/learn/tyre-recycling/ 2026-06-23T00:00:00Z

What happens to old tyres: illegal dumping law, rubber crumb applications, tyre-derived fuel, devulcanisation, EU End-of-Life Vehicle rules, how to dispose of tyres legally.

https://tirefitlab.com/learn/tyre-compound/ 2026-06-23T00:00:00Z

How tyre rubber compounds work: glass transition temperature, silica vs carbon black filler, summer vs winter compound differences, and how compound affects wet grip and rolling resistance.

https://tirefitlab.com/learn/tyre-mixing/ 2026-06-23T00:00:00Z

When mixing tyres is legal, when it is dangerous, and the rules: same-axle matching, summer/winter mixing, run-flat with standard, and EU/UK/DE/US regulations on tyre mixing.

https://tirefitlab.com/learn/tyre-warranty/ 2026-06-23T00:00:00Z

How tyre warranties work: manufacturer defect coverage, what voids warranty (road hazard, under-inflation, mounting damage), pro-rata tread wear warranties, and how to make a claim.

https://tirefitlab.com/learn/tyre-speed-rating-vs-use/ 2026-06-23T00:00:00Z

What happens when you exceed a tyre speed rating: heat buildup, structural failure risk, legal status in EU/UK/USA, how ratings are tested, and which rating your vehicle requires.

https://tirefitlab.com/learn/tread-wear-indicators/ 2026-06-23T00:00:00Z

How tyre wear indicators work: where to find TWI markers, what they look like, measuring tread depth with a gauge or coin, 1.6 mm legal limit, 4 mm winter safety threshold, and when to replace.

https://tirefitlab.com/learn/balancing-vs-alignment/ 2026-06-23T00:00:00Z

Balancing vs alignment: what each fixes, which symptoms point to which problem, when you need both, how much each costs, and what happens if you skip them.

https://tirefitlab.com/learn/cold-tyre-pressure/ 2026-06-23T00:00:00Z

How cold tyre pressure works: the 1 PSI per 10°F (0.1 bar per 8°C) temperature rule, when to check pressure (cold only), morning vs driven-tyre readings, altitude effects, and seasonal adjustment.

https://tirefitlab.com/learn/tyre-sidewall-markings/ 2026-06-23T00:00:00Z

Complete guide to every marking on a tyre sidewall: size string, construction code, load index, speed rating, DOT date, M+S, 3PMSF snowflake, UTQG, max pressure, country of manufacture, and brand-specific symbols.

https://tirefitlab.com/learn/tyre-pressure-fuel-economy/ 2026-06-23T00:00:00Z

How tyre pressure affects rolling resistance, fuel consumption, and CO₂ output: the 1 PSI / 0.5% MPG rule, what EU tyre label fuel efficiency grades mean, and what optimal pressure saves per year in fuel costs.

https://tirefitlab.com/learn/tyre-upsizing-downsizing/ 2026-06-23T00:00:00Z

What happens when you fit wider tyres, lower-profile tyres, or a larger rim: effects on wet/dry grip, ride comfort, fuel consumption, speedometer accuracy, wheel arch clearance, and tyre load capacity.

https://tirefitlab.com/learn/tyre-wear-rate/ 2026-06-23T00:00:00Z

How long tyres last: typical km per mm of tread depth by tyre category, factors that accelerate wear (speed, temperature, pressure, alignment, driving style), UTQG treadwear index explained, and when to replace.

https://tirefitlab.com/learn/tyre-cracking-ageing/ 2026-06-23T00:00:00Z

Tyre cracking causes: ozone craze, UV degradation, thermal cycling, and storage conditions. How to assess crack severity, when surface cracks are cosmetic vs structural, the 6-year age rule, and how to slow rubber ageing.

https://tirefitlab.com/learn/rim-types/ 2026-06-23T00:00:00Z

Rim types explained: steel stamped, cast aluminium alloy, flow-formed alloy, forged alloy, carbon fibre. Weight comparison, heat dissipation, repair cost, corrosion resistance, and which type suits which driving application.

https://tirefitlab.com/learn/tyre-fitting-costs/ 2026-06-23T00:00:00Z

Tyre fitting and mounting costs explained: what a tyre shop charges, what is included (mounting, balancing, disposal, valve), extras (TPMS service, alignment, nitrogen), price ranges by tyre size and region, and tips to avoid overpaying.

https://tirefitlab.com/learn/tyre-retreading/ 2026-06-23T00:00:00Z

Tyre retreading explained: the process of applying new tread rubber to a worn casing, safety standards (TRA, ECE R109), who uses retreads (trucks, aircraft, buses), whether retreads are legal and safe for passenger cars, and environmental benefits.