What Are Tyre Load and Speed Ratings and Do They Matter?
Posted on: 26/11/2024When it comes to the safety and efficiency of our vehicles, particularly for those of us who drive vans, SUVs, and pickup trucks, understanding the nitty-gritty of our tyres is crucial. Take a moment to think about the weight your tyres bear on a daily basis, especially when loaded up with goods, equipment, or even your latest DIY project.
That’s where the tyre load rating comes into play. Speed ratings are equally important; if you have a high-performance vehicle but fit it with tyres that have a lower speed rating, you won’t be able to use the car’s full capabilities safely on track. This guide will tell you all you need to know about load and speed ratings, how to check them and how to determine which ratings are right for your vehicle.
Tyre Ratings Explained
Want to understand the importance of load and speed ratings and find out how to check the ratings on your tyres? Read on for more details.
What is a Tyre Load Rating?
The tyre load rating is a rating given to individual tyres that indicates how much weight they can safely support at maximum air pressure. Represented by a numerical code, this is checked against a tyre load index (or tyre load rating chart) and corresponds to the maximum allowed weight in kilograms.
What is a Tyre Speed Rating?
Represented instead by a letter (which follows the load rating), a tyre’s speed rating determines the maximum speed a tyre can travel while at its maximum load - the load rating feeds directly into the speed rating. The later the letter comes in the alphabet, the higher its speed rating. For instance, a tyre with a L speed rating can travel at speeds of up to 75 mph, while a Y-rated tyre can travel up to 186 mph.
Is there a different speed rating for winter tyres?
Although winter tyres use the same speed rating system as summer tyres, they usually tend to have a lower speed rating. This is simply because they’re designed for different purposes; winter tyres focus on providing optimal traction in sub-zero temperatures, snow and ice, while summer tyres prioritise dry weather performance. As long as you don’t try to max out your car on the autobahn, the lower speed rating of a winter tyre shouldn’t cause you any problems!
What is the Difference Between Load Rating and Speed Rating?
Load ratings relate to the maximum weight a tyre can withstand before its structure is compromised, while speed ratings relate to the maximum speed a tyre can withstand safely (while it’s fully loaded).
To maintain the safety of your vehicle, it’s important to pay attention to both of these ratings.
How to Check the Load Rating on Tyres
To check your vehicle’s tyre load rating, look for a marking on the sidewall of the tyre. This takes the form of a long series of numbers and letters on the outward-facing surface of the tyre. The tyre load rating is the last two (or three) numbers, just before the tyre speed rating letter.
Check against the tyre load rating chart to find how much each individual tyre can support, then multiply by the number of tyres on the car to find the total tyre load. It should be more than the vehicle’s Gross Vehicle Weight Rating (GVWR).
For more detailed information on the various tyre sidemark ratings imprinted on your tyres, check out our guide to every tyre sidewall marking.
How to Choose the Right Tyres
So, you need new tyres. Here’s a guide to choosing the right ones for your vehicle and its intended usage.
What Tyre Load Rating Do I Need?
For the manufacturer’s recommended tyre ratings, find them written on a sticker on the driver’s door frame or in the owner’s manual should you need it. Some vehicles may even have them on a sticker behind the fuel filler cap. You may find that on heavier vehicles such as SUVs, some tyres will be marked as “XL”. Standing for “Extra Load”, this means that the tyre has additional reinforcement to handle the heavier loads of these vehicles.
Can You Mix Tyre Load Ratings?
Mixing tyre load ratings is possible but under certain conditions. For one, the front axle or rear axle must be fitted with identical tyres, right down to the tread pattern and brand.
If you can add up the individual loads of each tyre and it matches or is higher than the recommended tyre load of the vehicle itself, you can drive with mixed tyre load ratings. It is better to fit the higher-rated tyres to the rear axle.
Can I Use a Tyre With a Higher Load Rating?
While it is advised that you should fit tyres that have the load rating and dimensions recommended by the manufacturer, you can fit tyres with a higher load rating and maintain the safety of your car.
However, this does not change the amount of load your vehicle can handle; the vehicle itself will not be able to handle anything over the tyre load limit, so there is no tangible benefit to going higher. There are also potential downsides to uprating the tyre load rating for your vehicle, with stronger tyres possibly being less fuel efficient and even generating more tyre noise.
Can I Use a Tyre With a Lower Load Rating?
Fitting a vehicle with tyres lower than its recommended load rating is dangerous and prohibited by UK law. If the load rating is not adhered to, there are many ways in which the tyre can fail and lead to damage to your vehicle, you and your passengers.
For example, the tyre casing could be overloaded and start to strain, potentially causing a full blowout. In other cases, the edges of the tyre tread may start to bend under the weight of the car and separate from the tyre itself, causing a serious accident.
Where to Find Quality Tyres
If you’re looking to find new tyres with the correct load and speed ratings, LK Performance is the place to be. We stock a range of sizes from top brands that are guaranteed to fit your vehicle, no matter how large or nimble it is.
We recognise that it can be time-consuming to search for the exact tyre for your vehicle model, which is why we have made it our mission to simplify things. Use our online tyre fitment filter and enter your details found on the tyre sidewall markings, and we’ll filter our store to give you only the tyres that fit your vehicle.
From there, you can choose between high-quality tyres from pedigree brands including Pirelli, Firestone, Continental, Michelin and Goodyear. Browse our collection today and get a free tyre fitting at our vehicle maintenance centre.