Tire Load Index & Speed Rating
Turn the two characters after a tire size into a weight limit per tire and a top speed, and check a replacement against the original.
The Tire Load Index & Speed Rating tool works entirely in your browser. Nothing you type is uploaded.
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Об инструменте Tire Load Index & Speed Rating
The two characters stamped after a tire size are its service description, and they are two separate lookups. The number is a load index that maps to a maximum weight the tire can carry at its rated pressure; the letter is a speed symbol that maps to a sustained speed. Reading the letter off the alphabet gets the wrong answer, because the scale is famously out of order — H sits between U and V, at 210 km/h, because it was standardised before the rest of the range filled in. Paste a bare service description like 94V or a full size like 225/45R17 94V, and this tool reads both halves, converts them into kilograms, pounds, km/h and mph, and checks a replacement against the original.
Возможности
- Load index 70 to 130, in kilograms and pounds per tire
- Speed symbols L through Y, including the parenthesised (Y)
- Reads a bare service description or a full tire size
- Total capacity across all four tires
- Replacement check that flags a lower load or speed rating
- Full charts with your value highlighted
- Typical fitment note for each speed rating
- Every lookup happens on your device
Как использовать Tire Load Index & Speed Rating
- Read the size off the sidewall, e.g. 225/45R17 94V
- Type it in, or just the load index and speed letter
- Read the load in kg or lb and the speed in km/h or mph
- Enter a replacement to check it matches or beats the original
Пример
Ввод
225/45R17 94V
Результат
Load index 94 = 670 kg (1477 lb) per tire · 2680 kg across four
Speed symbol V = 240 km/h (149 mph)
A service description is two independent lookups, not one code.
Частые ошибки и устранение неполадок
- The load index looks far too low for the car's weight. — The index is per tire at its rated pressure, not for the whole vehicle. Four tires at index 94 carry 2680 kg between them — comfortably above a car that weighs 1600 kg loaded.
- A tire is marked ZR but has no speed letter after the size. — ZR was the old marking for anything above 240 km/h and does not carry a precise limit on its own. Modern tires add a service description — 94Y or 94 (Y) — which is the figure that counts.
- The replacement has a higher speed rating but a lower load index. — That is not a safe swap. Both figures have to meet or beat the placard, and load index is the one that matters most for a loaded family car or a van.
Часто задаваемые вопросы
- What does 94V mean on a tire?
- 94 is the load index, meaning each tire can carry 670 kg (1477 lb) at its rated pressure. V is the speed symbol, rated for sustained running at 240 km/h or 149 mph.
- Why does the speed rating H sit between U and V?
- H was standardised as the high-speed rating long before the scale was filled out, and it kept its 210 km/h value when the rest of the letters were assigned. That leaves the sequence reading S, T, U, H, V, W, Y rather than running alphabetically.
- Can I fit tires with a higher speed rating than my car needs?
- Yes, and it is common. A higher rating brings stiffer construction, which usually sharpens steering response at the cost of some ride comfort, and it never reduces the tire's legal suitability.
- Is it legal to fit a lower load index than the placard?
- In most countries it is not, and insurers treat it as a modification. The placard figure is chosen for the vehicle's maximum axle load, so going below it means the tire is running beyond its rated capacity when the car is full.
- Where do I find the load index my vehicle needs?
- On the tire placard, usually inside the driver's door jamb, in the fuel filler flap or in the owner's handbook. It lists the original size along with the load index, speed symbol and cold inflation pressures.
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