Quick Answer: Run-Flat or RFT tyres can operate for short distance after a puncture has caused the tyre to lose air. Also many many modern cars have RFT’s instead of a spare to save weight and improve fuel efficiency.
What is a RUN FLAT tyre?
Most people have heard of run-flat tyres but don’t really know what they are or how they work.
In this blog post, we’ll explain everything you need to know about run-flat tyres, including what they are, how they work, and the advantages and disadvantages of using them.
By the end of this post, you’ll be an expert on run-flat tyres – and you’ll be able to decide whether they’re the right choice for your vehicle.
We’ll also explain how to get the best possible deals on run-flats from your nearest tyre shop who specialise in fitting run-flat tyres.
What are Run-Flat Tyres? (RFT)
Run-flat tyres are a relatively new tyre technology, specially designed by tyre manufacturers so they can continue to be used even after a puncture.
Most punctures will cause loss of tyre pressure – causing a tyre to deflate, but with a run-flat tyre, the tyre is reinforced with special materials and can still be driven on even after it has been punctured. Usually, a run-flat tyre can be driven on after a puncture for up to 80 kilometers at around 80 kph even after it has been punctured.
How Do Run-Flat Tyres Work?
Most regular tyres are filled with air pressure, which helps to support the weight of the vehicle and also helps to absorb shock from bumps in the road. When a puncture occurs, the air escapes from the tyre and the tyre deflates. This can cause problems because the weight of the car is no longer supported and shocks from bumps are no longer absorbed as effectively.
With a run-flat tyre, there is a reinforced sidewall that prevents the tyre from collapsing when the air pressure is lost. This means that even if you get a puncture, you can still continue driving with your tyre secure until you can get to a safe place to change your tyre.
How do I know if I’ve got a punctured tyre if I’m using run-flat tyres?
Since run-flat tyres have both stiffer sidewalls and a thicker sidewall compared to a normal tyres, they won’t look ‘flat’ like a normal tyre would.
So, how do you know if you’ve got a tyre puncture, tyre failure, or pressure problem?
The answer lies with your tyre pressure monitoring system (TPMS). This is a system that checks the pressure in each of your wheels continually – lighting up a dashboard warning if it detects a tyre puncture or loss of air pressure.
Today, all cars are required to have a tyre pressure monitoring system as standard. As such, you simply need to keep an eye on your warnings lights to work out if you have a problem.
Advantages of Run-Flat Tyres
Like any product, run-flat technology have pro’s and con’s.
Let’s take a look at each:
Pro’s of run flat tyres:
- You can continue driving even after a puncture, which means you’re less likely to be stranded in an unsafe location.
- Your car does not require a spare tyre, so you save space in your trunk and can save weight – helping fuel economy.
- You don’t have to worry about changing a flat tyre for a spare wheel by the side of the road, which can be difficult and dangerous.
Con’s of run-flat tyres:
- Price: Run-flat tyres tend to be a little more expensive than normal tyres
- They provide less comfort because they’re stiffer than regular tyres.
- They’re not suitable for all vehicles – you’ll need to check whether your car is compatible before you buy them.
What’s the maximum speed of run flat tyres?
Run-flat tyres generally have a maximum speed rating of 80kph – although some are slightly higher “when damaged” otherwise normal speed rating applies.
Most tyre manufacturers will recommend that you drive at this speed or less for a maximum of 80kms. This is usually enough distance to get you home or to a tyre workshop for further help.
Can you repair run-flat tyres?
It depends on where the damage is, please refer to this article on puncture repairs to learn more.
Run flat tyres can be repaired in some circumstances but this will vary depending on the make, model and severity of the damage to the tyre. A tyre professional will be able to assess your tyres and make the best recommendation for you.
Can you swap run-flat tyres for normal tyres?
Yes and no:
- If you car has no room for a spare the answer is no.
- If you have room for a spare, yes you can
However I say replacing run-flat tyres like-for-like is always the best option.
Should I get run flat tyres fitted to my car?
Run flat tyres make sense for vehicles that don’t have space for a spare tyre or for drivers looking for a temporary solution in the event of a flat tyre. They offer peace of mind and the knowledge you won’t ever get stuck roadside or in an unsafe area if you get a flat. However, they do come with restrictions and aren’t appropriate for every car.
Specialist markings on run-flat tyres
Now we have tyre sizes explained, it’s worth looking at other markings that can impact the tyres you need – and some tyre manufacturers have products known as ‘Run-flat tyres’. In many cases, where a vehicle manufacturer supplies a car with run-flat tyres, they’ll recommend you always use run-flats.
These are designed with a tough sidewall that won’t flatten even if you loose pressure. This means there’s no need for swapping to a spare wheel or trying a roadside repair.
You might be asked if your tyres are ‘run-flats’ because, as mentioned, these are sometimes added as standard by a vehicle manufacturer. If so, you’ll see see different markings depending on the brand of tyre on your car.
Goodyear, Bridgestone, Dunlop, and others
These tyres use an ‘ROF’ marking on their sidewall. This stands for ‘Run on Flat’.
Some other Goodyear tyres
Some Goodyear tyres use the term ‘EMT’ – meaning ‘Extended Mobility Technology’.
Michelin, Yokohama, and others
These brands use either ‘ZP’ or ZPS’ – an in-house designation used to identify run-flats.
You may see adverts from tyre retailers that say things like “Run Flat Tyres BMW”, “Run flat tyres Mercedes” or similar. This is because these manufacturers tend to fit run-flats on their vehicles as standard – so owners are often looking specifically for replacements.
Although some vehicles come from the factory with run-flats – you don’t have to replace them like-for-like. For instance, a car equipped with Bridgestone run-flat tyres will be perfectly safe if you swap to Pirelli run flat tyres – for example.
Conclusion
Overall, run-flat tyres typically have more advantages than disadvantages. If you’re looking for a tyre that will keep you safe in case of a puncture, then run-flat tyres are definitely worth considering.
However, it is usually a bit more expensive to fit run flat tyres compared to regular tyres and they might not be suitable for all vehicles. Do your research before purchasing run-flat tyres to make sure they’re right for you and your car!
Getting the best price for Run-flat tyres
If you need to replace a run-flat tyre, you’re probably not wild about the idea of calling around every auto shop nearby and getting quotes! This is understandable – so the team here at Auto Hero have made the job quick and simple!
Just give us a few details about your car – then we’ll shop around on your behalf. We’ll get bids from tyre retailers near you that are motivated to win your business. You’ll be able to see all the prices from local tyre specialists – then choose one that’s right for you!
Written By
Matt Banks
Matt is the founder of Autohero.com.au and has been hooked on cars and repairs ever since childhood. A veteran in automotive since leaving school, Matt has completed his trade as a panel beater and is across all things with wheels.
His first car was a 1967 FORD XR Wagon followed by a string of collectable Holden’s.
Have a question for Matt? leave a comment below.