Can I Put Lower Speed Rated Tyres on My Car?

With so many tyres on the market, all of which have their own individual features and properties, it can be hard choosing the right set that works for you. A commonly asked question is whether or not motorists can fit tyres with a lower speed rating than recommended by their car’s manufacturer. The short answer to this question is no, however there are some tyres that fall outside of this which we’ll cover in this article. 

Can I Fit Tyres With a Lower Speed Rating?

It is not recommended to fit new tyres with a lower speed rating to what is recommended for your vehicle. Whilst choosing to equip your car with a higher speed rating is safe, replacing your tyres with those of a lower speed rating will compromise the safety of your vehicle. This is why it is super important to ensure you know the speed rating that is recommended for your car, and never fit tyres with a lower speed rating than the original fitments. 

The only time it is safe to dip below the recommended speed rating is when fitting certain winter tyres to your vehicle. These specialist tyres often come with a lower speed rating due to the fact drivers should be going slower in the winter months, and thanks to their specialist features that allow them to perform safely and efficiently in challenging weather. There are other requirements to meet here though, which we will discuss further on in this article. 

What are the Consequences of Fitting Lower Speed Rated Tyres?

There are many consequences that come with fitting lower speed rated tyres than what is recommended by your car’s manufacturer. These consequences include legal issues like void insurance, and issues with the safety of your vehicle. 

It is most important to be aware of the safety implications that are associated with fitting lower speed rated tyres to your car. Tyres with a lower speed rating are not designed to cope with the heat that is generated when driving at high speeds. If you fit your car with low speed rated tyres, but continue to drive at high speeds, you will be at risk of your tyre’s losing performance, losing control of your vehicle, or worse – a tyre blowout. 

These safety risks not only put yourself in danger, but the safety of other drivers is compromised too. That is why further consequences come with incorrect use of speed ratings, such as invalidated insurance in the event of an accident, or your car’s manufacturer warranty becoming void. You can also be fined by the police for having the wrong tyres fitted to your car. 

Choosing a Lower Speed Index for Winter Tyres

It is legal to choose a lower speed index when equipping your car with winter tyres, as long as the tyres have the 3PMSF and M+S marking. This does mean that you will need to ensure you don’t exceed the maximum speed rating of the tyres you choose. It is required to place a reminder inside your vehicle with the new speed limit so you don’t forget. 

Winter tyres often don’t have the same speed ratings as summer tyres because they are designed for driving in difficult weather conditions like snow, ice and heavy rain. In the winter months when driving in these challenging conditions, drivers should be going at a slower pace, meaning a lower speed rating wouldn’t be exceeded. 

Can I Switch to a Tyre With a Higher Speed Index?

It is perfectly safe to replace your tyres with those of a higher speed index. In fact, this is often recommended practice to equip a vehicle with tyres that match or exceed its maximum speed rating. This is because tyres with a higher speed index are much more equipped to cope with the heat of high speeds and provide much safer and controlled acceleration, handling and even braking. 

Tyres with a higher speed index can be relied upon for their performance even at high speeds, meaning drivers will be safer on the roads no matter what. When driving at high speeds, tyres are put under more pressure and they generate more heat, along with the vehicle turning faster and braking from a higher speed. That is why higher speed index tyres are specially designed to cope with these demands, making them a safer choice for all. 

Tyres that have a higher speed rating are designed to provide optimum acceleration, which is great for improving fuel efficiency. Car’s typically require more energy to accelerate than they do to drive at a consistent speed, meaning if you’re able to effortlessly accelerate with the tyres to accommodate, you’ll be using less fuel to do so. 

What is a Tyre Speed Rating?

All this talk about high and low speed ratings, but what exactly is a tyre speed rating, and why is it so important? Tyre speed ratings indicate the maximum speed a tyre is designed to drive at. This is a legal rating, meaning the tyre is only legally approved to drive at the stated speed and no higher. 

Speed rating is based on tests whereby a tyre is tested at 6.2mph increments until it reaches the speed required. 

Tyre Speed Rating by the Letters

Speed ratings are represented by letters that correspond with the maximum legal speed. We’ve included the tyre speeds with their corresponding letters in the table below: 

How to Find Your Tyre Speed Rating

Tyre speed ratings are displayed on the tyre’s sidewall with the size information and load rating. The speed rating is the very last letter at the end of the sequence and follows the load rating. For example, a tyre that is marked with: 205/60R16 92V, the speed rating is V. If you’ve not purchased the tyre yet, you will find all this information on the tyre label. 

To find your vehicle’s recommended tyre speed rating, take a look in your vehicle’s handbook. This is also displayed on a sticker that is placed either on your fuel cap or on the pillar of your driver’s side door. 

Why is Tyre Speed Important?

Tyre speed rating is used to keep motorists safe, by letting them know the maximum speed their tyres are capable of safely driving at. Exceeding this speed puts added pressure on the tyres through the heat that is generated by driving at a higher speed. If the tyre can’t cope with the added heat, it is at risk of failing, which is particularly dangerous especially at high speeds. 

What are Tyre Speed Ratings For?

Speed ratings are designed to ensure the safety of your tyres. Speed ratings indicate the maximum speed a tyre should be driven at for safety and performance. They are a legal requirement and should not be exceeded, as mentioned above. 

Can Fitting the Wrong Tyres Affect my Car Insurance?

Fitting the wrong tyres for your car could lead to your policy being invalidated in the event of a claim. This applies to using tyres that are of a lower speed rating than required, along with many other factors. Tyres with a lower speed rating are viewed as a modification by insurers, deeming the car not fit for the road. This would lead to an insurance policy being void due to having the wrong tyres. 

Other factors to consider to ensure your tyres are compliant with your insurance include size, load rating, tyre damage, mixing tyre types. 

Conclusion

So, when it comes to finding new car tyres, it is important never to choose tyres with a lower speed rating than required by the manufacturer. Whilst higher speed rated tyres can provide many safety benefits, lower speed rated tyres come with many safety implications. To ensure you are as safe as possible on the roads, and to keep yourself and other motorists out of potential danger, always follow your car’s recommended information when it comes to tyres. This will also save you from legal complications like invalidated insurance or manufacturer’s warranty too! Discover more tyre safety information to ensure you are always driving legally and safely.