Run Flat Tires: How They Work and What Makes Them Different

Discover how run flat tires work and what sets them apart from ordinary tires.

If you’re in the market for a new set of tires for your vehicle, you may have come across the term “run flat tires.” But what exactly are run-flat tires, and how do they work?

In this article, I will pack with all the vital information about run-flat tires. So, if you want to put an end to those stressful tire blowout situations, keep reading. 

What Are Run Flat Tires

Run flat tires are made to support the weight of the car even if they are punctured or lose pressure. This is different from ordinary tires which can be seriously damaged if they are driven while flat. With run flat tires, you can keep driving your car to a safe place or repair shop without having to change a tire on the side of the road.

How Do Three Types of Run Flat Tires Work

Run flat tires generally come in three types: self-supporting, self-sealing, and auxiliary-supported. 

Differences between ordinary tires and self-supporting run flat tires when they are inflated and deflated

Self-supporting is the mainly used technology for run flat tires. Compared to ordinary tires, self-supporting run-flat tires have reinforced sidewalls made of specialized rubber compounds. These sidewalls can withstand the vehicle’s weight and maintain their shape even under low or no air pressure. 

Self-sealing run flat tires work by using a sealant that is stored within the tire. When the tire is punctured, the sealant is forced out of the puncture hole by the air pressure within the tire. The sealant then fills the hole and hardens, creating a temporary seal that prevents air from escaping. 

Auxiliary-supported technology relies on an additional support system, such as a special ring inside the tire. The support ring is typically made of a strong, rigid material such as steel or Kevlar. When the tire loses air pressure, the support ring takes over the role of supporting the weight of the vehicle.

How Far Can You Drive on Run Flat Tires

In general, run flat tires can be driven for up to 50 miles (80 km) at speeds up to 50 mph (80 km/h) after a puncture occurs. But some run flat tires may have a shorter or longer driving distance. It is better to consult the manufacturer’s specifications for your specific tire model.

While run-flat tires can help you get to a repair shop or a safe location after a puncture, you should only drive it for a short period. Driving on a flat or damaged tire can cause further harm to the tire and the wheel. As such, it is recommended to replace a damaged tire as soon as possible to ensure safe and reliable driving.

Pros & Cons

Over the past several years, many drivers have been skeptical about the effectiveness of run flat tires compared to standard tires. However, according to a study released by JD Power in 2018, run flat tires have significantly closed the gap in customer satisfaction with standard tires since their previous survey in 2015.

Pros

Run flat tires allow drivers to continue driving for a short distance after the puncture. This is especially helpful in cases where you can’t stop to change a tire, like on a busy highway or when it’s pouring down.

Run flat tires can maintain stability and control after a puncture or blowout. With standard tires, a sudden loss of air pressure can cause the vehicle to swerve or even spin out of control. However, run flat tires can provide a stable driving experience even with a flat tire. This will reduce the possibility of a dangerous situation for the driver and passengers. 

Having run flat tires can free up more space in the trunk of your vehicle. Typically, spare tires are located in the vehicle’s cargo area, taking up valuable space that could be used to store other items. By utilizing run flat tires, manufacturers can remove spare tires and maximize the available space in the vehicle. This can be good news for drivers who frequently transport larger items or need to pack a lot of gear for a trip.

Cons

Run flat tires may produce more road noise and reduce overall ride comfort compared to standard tires. This is because run flat tires have stiffer sidewalls, which can transmit more vibrations from the road to the vehicle’s cabin.

Mostly, run flat tires cost more than regular tires because of the additional materials and technology. Also, they may not be repairable in the same way that standard tires are. If you experience a puncture or other damage to a run flat tire, you might need to replace the whole tire instead of just fixing it. 

Another challenge with run flat tires is their limited availability. If you happen to get a flat tire in a small town or remote area, it may be difficult to locate a replacement run flat tire nearby. This can be especially problematic for drivers who depend on their vehicles for work or travel long distances. 

How Do Drivers Know When a Run Flat Tire Has Blown?

TPMS warning light on the dashboard

One of the critical components of a run flat tire system is the tire pressure monitoring system (TPMS). Without a TPMS, detecting a puncture can be incredibly difficult since run flat tires can still function even when deflated. When a tire blows, the TPMS will notice the loss of tire pressure and activate a warning light on the vehicle’s dashboard. This warning light is typically a yellow or orange icon that looks like a cross-section of a tire with an exclamation point in the center. 

However, TPMS systems are not foolproof and should not be relied upon exclusively to ensure safe tire pressure levels. It is still recommended to regularly check the tire pressure with a pressure gauge.

For more information about the TPMS, please read this article – TPMS 101: Understand Your Tire Pressure Monitoring System.

How to Tell If a Tire Is Run Flat

This run flat tire has the code “RSC” on its sidewall

To determine if a tire is a run flat tire, you can look for specific codes on the sidewall of the tire. Here are some examples of some well-known tire brands:

  • Bridgestone –  ROF (Run On Flat), RFT (Run Flat Tire), or RSC (Run-Flat System Component)
  • Continental – SSR (Self-Supporting Run Flat)
  • Dunlop –  ROF (Run On Flat) and DSST (Dunlop Self-Supporting Technology)
  • Goodyear – ROF (Run On Flat) and EMT (Extended Mobility Technology)
  • Michelin – ZP (Zero Pressure)
  • Pirelli – RSC (Run-Flat System Component) 

Another way is to consult your owner’s manual. If your car still has its original tires and they are run-flat, the owner’s manual will explain all the information you need to know about run-flat tires and TPMS. 

The last method is to check if you have a spare tire. Cars that come with factory-installed run-flat tires may not provide a spare tire in the trunk. 

How Much Are Run Flat Tires

The cost of run flat tires can vary depending on the manufacturer, size, and type of tire needed for the specific vehicle. On average, run flat tires may range between $150 and $300 per tire. For some high-end brands, it could even charge $500. Besides, they also require special wheels and installation procedures, which can add to the overall cost.

The Bottom Line

Run flat tires prevent full tire failure in the case of a puncture or blowout, making driving safer and reducing roadside stops. However, it does not mean that run flat tires are invincible. You should still regularly check them for proper inflation and wear. 

Additionally, not all vehicles are compatible with run flat tires. So, consulting with a professional before making the switch is vital. 

No matter what type of tires you have, remember to put safety first and keep your tires in good shape. This will achieve the best driving experience possible.

Picture of Nick Wang

Nick Wang

Nick is the guy behind Tire Think. He’s been working as an engineer in the tire industry for 8 years, focusing on endurance indoor testing operations.
Share the Post: