After an accidental puncture, driving on a completely flat tire on the highway is not ideal. Being stranded with a flat tire, with no spare to use is also a nightmare. While cars with flat tires technically can be driven, doing so will further damage the tires, the rims, and possibly the vehicle as well.
Modern auto manufacturers have foregone the spare tire, and they equip their new vehicles with run flat tires. But why? Why are they trying to leave spare tires in the past, urging consumers to look for run flat tires for sale?
Also, what is a run flat tire? How does it work? Is it really better to use them instead of regular tires?
Let us guide you through everything you need to know about run flat tires!
What are Run Flat Tires?
Run flat, or never flat tires are models that feature stronger constuctions. This reinforced sidewall structure enables its limited, temporary performance even after air pressure loss.
In other words, when psi levels drop, due to a puncture or some other damage, the tire will not immediately go flat. Instead, the sidewall withstands the weight of a vehicle and its passengers for about 50 miles, at the maximum speed of 50 mph.
Run flat technologies were the next step in tire manufacturing. However, run flats are not as new as some people think them to be.
The first self-supporting run flat tire was introduced to the tire market in 1934. True, this tire relied on a safety rim on its inside, made of a special foam lining. This tire technology was first used for military and specialized vehicles, as it was too expensive for everyday use.
The next part in the run flat history was the Captive Air run flats. These were designed and manufactured by the team up between Chrysler and Goodyear. The Captive Air were RFT tires that used an interlining to withstand the extra weight.
Nowadays, most tire brands manufacture tires that don't go flat immediately after receiving a puncture. These models allow the vehicle to continue driving, instead of being stranded on the side of the road - offering a safer driving experience.
Run flats are usually manufactured for vehicles without space for a spare tire. This makes them more convenient for cars with small trunk space.
How do Run Flat Tires Work?
In order to discuss how run flat tires work, we need to talk about regular tires for a bit.
Regular tires require air pressure to maintain their ideal tire shape. Correct psi levels need to be maintained so the tire can perform as it should and withstand the weight and pressure placed on it.
On the contrary, run flat tires, or tires that don't go flat, offer limited performance after air pressure loss. In other words, run flat tire on the road can perform for, usually, 50 miles up to the speed of 50 mph. However, the speed limit and distance will depend on the specific tire and vehicle combination.
So, how do run flats work exactly?
A run flat technology will use reinforced sidewall structures. Once pressure loss occurs, construction provides a small distance frame for the vehicle to reach a safer located, before the tire got flat. Yet, there are different tire technologies that manufacturers use. Let's take a look at how they work.
Self Supporting Run Flats
Most run flat technologies are self-supporting run flats. These tires feature a strengthened sidewall construct that maintains the tire shape if a puncture causes pressure loss. Therefore, the self-supporting structure withstands the vehicle's weight, enabling the tire's limited performance.
Support Ring No Flat Tires
The supporting rin no flat tire technology uses a ring of stiff rubber, or some other structure, to support the tire when pressure levels drop. Instead of relying on their sidewalls, these tires will place their faith in this additional structure to keep them in motion. These models are considered to be tires that don't go flat.
How Long do Run Flat Tires Last?
Thanks to modern technologies, run flats last almost as long as standard tires do. The difference between their longevity is about 6,000 miles. However, many brands have started offering treadwear warranties with their run flat tires, which range anywhere from 20,000 miles to 80,000 miles.
Yet, keep in mind that fixing a run flat tire is out of the question. Once it was driving on flat, it should not be used again as its stiff sidewalls are compromised. Therefore, as long as a run flat tire repair is not needed, they will last about as long as standard tires.
Run Flat Tires vs Regular Tires
Now, look at the difference between run flat and standard tires. What are the run flat tires' pros and cons compared to their regular cousins?
The Benefits of Run Flat Tires
The most important feature of tires that never go flat is that they eliminate the possibility of the vehicle driving on deflated tires. They offer a secure performance, minimizing the possibility of the vehicle becoming stranded on the side of the road.
Additionally, thanks to this, they eliminate the need for spare tires. Therefore, vehicle owners will have more space in the trunk for other things.
Pros of run flat tires:
- Limited, temporary performance after pressure loss
- No need for spare tires
The Benefits of Regular Tires
Now, let's talk what standard tires offer that run flats don't.
Regular tires are cheaper than run flats. Due to their construction, the price of run flat tires is higher. Therefore, run flat all season tires will cost more than standard new tires from the same category.
Their construction also makes run flat tires heavier. Compared to them, regular tires weigh less, which offers better fuel efficiency, a longer-lasting tread life, stable high speed performance, and optimized controllability.
Regular tires can be repaired. If they get punctured on their tread area, these tires can be patched or plugged. As a result, their service life is not completely cut short when they get damaged.
Pros of regular tires:
- Cheaper than run flats
- Optimized fuel economy and overall usability
- Can be patched, plugged, and repaired
How Much do Run Flat Tires Cost on Average?
The cost of run flat tires is higher than regular tires. This is due to their reinforced sidewall construction, which takes more to manufacture. Self-supporting technologies increase the production cost of each run flat tire, hiking their market price as well.
So, how much does a run flat tire cost?
The price of a tire that never goes flat will greatly depend on its brand, performance type, and size. Needless to say, run flat truck tires are more expensive than passenger car RFT tires. Additionally, top brands will charge more for their models compared to lesser-known run flat manufacturers.
The run flat tire price can range from $150-$500 per tire. It will vary depending on what you need to purchase.
Generally speaking, lower-end brands that produce the cheapest run flat tires offer them for about $150-$250. On average, a mid-tier brand will charge around $300-$400 on average for their models. Lastly, top-tier tire brands can sell their tires for around $500/tire.
Michelin Run Flat Tires (High Price, High Safety)
The most expensive tire models are usually manufactured by the big shots of the industry. But, are run flats worth it? Do higher prices run flats come with better technologies?
Well, sadly for our wallet, the best run flat tires in the market are more expensive than the rest. However, their price point comes with better quality.
Furthermore, those who started making run flats sooner have had more time to perfect their tire technology. As a result, Michelin RFT tire sets are one of the best run flats available for purchase. Or maybe we should say ZP tire sets since Michelin's run flat technology is called Zero Pressure.
But, which are the most popular ZP tires on the market? Check out our short run flat tires review below!
Michelin Primacy MXM4 ZP
Apart from the Zero Pressure technology, the Michelin Primacy MXM4 ZP uses additional methods to increase its performance and safety. From the MaxTouch Construction to the 3D Variable Thickness Sipe Technology, the tire increases overall service life and year-round traction. On the other hand, the ComfortControl Technology ensures high driving comfort levels, while the BAZ structure enhances its handling and maneuvering.
Michelin Latitude Tour HP ZP
All Season run flat tires are not hard to come by. One such example is the Michelin Latitude Tour HP ZP which provides year-round traction, fuel efficiency, optimized handling, and high driving comfort levels, on top of its run flat capability. The FAZ technology optimizes its surface contact, boosting steering responsiveness and driving stability. It also lowers road noise and vibration levels. The Green X technology ensures its fuel-conscious performance.
Michelin Pilot Sport A/S 3+ ZP
Michelin's Zero Pressure run flat technology is not the only improvement offered with the Pilot Sport A/S 3+ ZP. The Variable Contact Patch 3.0 boosts the tire's usability while increasing its controllability with better road contact. Additionally, rigid shoulder blocks increase cornering and maneuvering. Braking is shortened with the silica-based compound. The Total Performance technology ensures its driving durability, fuel efficiency, and performance. Year-round traction is promoted with the Helio+ compound.
Can You Patch a Run Flat Tire?
No, you cannot fix a run flat tire. Once it loses air pressure, driving on a flat tire compromises the internal structure. The structure withstood the vehicle's weight alone, which can lead to structural damage that will render any run flat tire fix useless.
How Long can You Drive on Run Flat Tires?
Most tires manufactured with a run flat technology offer a 50 mph performance for 50 miles. This is the general rule, yet it can be both lower and higher. Depending on the tire model and vehicle type a run flat tire set can offer anywhere from 25-mile to 200-mile performance after loss of air pressure.
Can you Put Air in Run Flat Tires?
Run flat tires need air pressure to perform. Their capability to run without psi levels is extremely limited. Therefore, you need to put air in run flat tires. In fact, you need to check its psi levels regularly, like with a regular tire.
How to Tell if a Tire is Run Flat?
Run flat tires are marked on their sidewall as such. These markings might specifically state "run flat" or have the manufacturers' codes (such as ZP, DSST, SSR, EMT, etc.). Additionally, these tires can also show a flat tire with an arrow pointing away from it to represent its run-flat capability.