What Are Runflat Tyres, And How Do They Work?
If your car has runflats, these tyres prevent blowouts and allow you
to drive on a "flat" tyre for longer. Here's how they work
and how you should treat them.
Runflats are a kind of tyre first developed in the 1980s. Despite being in production for over four decades now, they've become popular for modern cars in just the last few years.
They offer better performance and improved safety features, but it can be hard to identify them at a glance. In fact, many people own cars with runflats and don't even know it.
So what are runflats, do you need them, and are they worth it? Better yet, do you already have them? Let's explore the ins and outs of this tyre and see if they're right for you:
What Exactly Are Runflats?
In simple terms, runflats are tyres with specially reinforced sidewalls. If you get a puncture that would otherwise flatten the average tyre, you can continue driving on runflats at a limited speed and for a limited period (a maximum speed of about 50 mph for a maximum of about 50 miles). This is generally within easy reach of an Autofusion centre.
With a normal tyre, driving on the deflated wheel for any length of time could result in a warped sidewall or even a damaged wheel well. That's why it's recommended to immediately pull over on a standard flat tyre, so you can change it out or call for roadside assistance.
Runflats give you more time and greater flexibility on when (and where) the tyre is addressed. Better yet, two of their three main advantages focus on safety:
- Better Control : The strengthened sidewall helps keep your car under control in the event of a puncture
- Better Placing : You don't have to change the wheel at the side of the road (one of the most dangerous situations you can put yourself in), especially on busy carriageways
- Less Weight, More Space : No spare wheel means more space in the boot, less overall weight (after all, spare wheels are heavy), and, as a result, improved fuel efficiency and mileage.
Do I Have Runflats?
Runflats look nearly identical to regular tyres, so assessing them by sight is difficult. In practical terms, to tell if you have runflats, open the boot of your car. Lift the floor cover up and see what lies beneath.
If it's a spare tyre nestling in the cavity or a foam-filler repair kit, then your car isn't standardly fitted with runflats. That's because these tyres are not designed to be immediately swapped out on the road or mended with foam. If you don't see replacements or repair kits, your vehicle may be fitted with runflat tyres – or should be.
Beyond that, if your car is newer or belongs to a luxury brand, the chances of it being equipped with runflats are high. More and more vehicle manufacturers are including runflats as "original equipment" (OE), including brands like:
- Mini
- BMW
- Mercedes
If you're still not sure, check in with a garage and have a qualified mechanic assess your tyres. The expert can determine if they are runflats, and also give you a quote on replacing them in the future if they become damaged.
How Do Run Flat Tyres Work?
In addition to the reinforced sidewalls, runflats are often used in conjunction with a "tyre pressure monitoring system" (TPMS). This feature is more likely in luxury cars or newer vehicles, while cars that have been equipped with runflats after manufacturing may lack it.
The automatic alert system notifies you of when the runflat tyre has been punctured, so you know to get it replaced. Otherwise, the reinforced design may work so well that you do not notice the change immediately. The sooner you get the tyre changed, the better, so you do not drive beyond the runflats' 50 mile limit.
Doing so could wear down even the best sidewall, leading to the same damage an average tyre would experience. Runflats are designed to keep you safe and buy you time, but they can't run with a puncture forever.
Can I Change Run Flat Tyres With Non-Run Flats?
If your car has runflats, you may be tempted to switch to normal tyres once your current set needs replaced. This has advantages, of course, since runflats are often more expensive, costing upward of $200-$500 for each individual tyre.
It's possible to change out runflats with standard tyres. The main complication will come if your car has runflats as original equipment (OE), since the boot will not be designed to hold a spare tyre. In this case, you may have nowhere to store a spare, demanding that you call for roadside assistance if you get a flat while driving.
If your car was upgraded to runflats later on, then you will have the necessary space. The disadvantage will merely be having less time to drive on a flat tyre.
If you'd like a personal quote on new runflats, have any questions about your current tyres, or need replacements, reach out to your local Autofusion centre. One of our expert professionals will be happy to guide you.