Tire Sealant is a liquid you put in your tire to repair small punctures. It’s used by many car enthusiasts as a long term solution to fix flat tire issues.
But how long does tire sealant last? The only correct answer is until you can drive it to the nearest shop. Depending on tire sealant is dangerous, especially if you expect it to last for long periods of time. Using tire sealant when a simple plug or patch can be used is never advisable.
We will cover what tire sealant actually is, and why tire sealant shouldn't be depended on for more than a couple hours of use. We will also touch on the acceptable usage of tire sealant and finally, we will cover what tire sealant is industry standard.
As a tire tech in a shop, I’ve come across countless tires with sealant, and it’s always a mess. We were actually told to refuse service to customers who want a tire patched that’s had sealant applied. And rightly so, since the sealant can actually cause explosions if ignited by a spark.
The goal of tire sealant is to mimic the functionality of the tire’s inner lining. Sealant does this by coating the tire’s inner lining and acting as a pre-emptive measure to a future leak. When a puncture occurs, the sealant rushes into the hole and plugs it using fibers built into the sealant.
The liquid acts as a transportation mechanism for the fibers, since the air is being rushed out. Therefore, the liquid sealant rushes out with leaking air, leaving the fibers, and a plugged tire, behind.
Tire sealant also offers a way to inflate a flat tire, by adding compressed air with sealant, the hole is plugged, and you have an inflated tire.
But if your tire is “rim-flat”, meaning, the tire is so flat, the rim is touching the ground, you’re going to need a whole tire sealing kit.
This is because the compressed cans of air that tire sealants are often sold do not contain enough air to properly inflate the tire.
Whether your use case is preventative or a solution to a problem, there’s something to remember. The plug that’s left behind originates from liquid. The viscosity of the liquid will make up a portion of the plug and the state of liquid varies.
By using tire sealant, you're implying that you’d like to depend on a liquid plug to maintain the full weight of the vehicle while in motion. It’s just not a safe option. Using liquid where rubber meets the road is dangerous not only for you, but for other drivers on the road.
Tire sealant has caused numerous deaths and injuries, and tire sealant companies have paid out millions of dollars in lawsuits.
It’s because the dependency one can expect from tire sealant is nowhere near what’s actually provided. It’s almost a 50/50 chance of whether the tire sealant will fix a flat tire. And if it does fix it, it’s another 50/50 chance as to whether the sealant will hold.
When Is It OK?
The use cases of tire sealant are small in number. Because of the unreliable nature of the liquid plug, driving for more than 15-20 minutes on sealant is not recommended. But in emergencies, such as being stuck on the side of the highway, and needing to pull over further, tire sealant is ok to use.
Other common use cases for tire sealant are for ATV’s. Riders will coat their tires with the sealant before a trek so they aren’t totally stranded if a flat occurs.
Sealant is quite effective for ATV’s since they run on low pressure, causing more flex and opportunity for the hole to be filled. Furthermore, tire sealant is also used in tractor tires and small engine vehicles that travel at very low speeds.
Sealant is used as a preventive measure to attempt a seal on a puncture before you notice it. In the case of tractors, you can drive on a sealant plugged tire, and depend on it to function correctly, because you’re moving very slowly.
So when the sealant plug fails, you just stop the tractor. But if you’re driving down the highway at 60mph, and the sealant plug fails, that’s a different story.
It’s considered acceptable to use tire sealant on vehicles that don’t come with any electronics inside the tires such as TPMS systems.
Using fix-a-flat on a tire with TPMS systems can damage the sensors by plugging up the holes the sensors depend on to get a valid reading. If you use sealant on a vehicle with TPMS, you can expect a TPMS light to come on.
If you are stranded on the highway, and have no triple A, but a tire sealant can, it’s ok to put tire sealant in your tire. But drive well below the speed limit, with your hazards on in an off lane until you can get to a safe spot, or more preferably, your mechanic.
Using tire sealant in any of these other situations is not recommended. Mainly for safety reasons, but also, because you will just have to keep applying the sealant, time and time again. You’ll save money, time, and headaches if you just take it to get properly patched.
Which Tire Sealants Are Commonplace?
While tire sealants are generally considered dangerous by all mechanics, they are still being sold in auto-parts shops and other retail stores. Many sealant companies have gone bankrupt from lawsuits leaving only a few behind.
So by process of elimination, they can be considered the best. The most common tire sealant is Slime. Slime is the United States’ best selling tire sealant. You can purchase Slime in a variety of packages ranging from single cans to gallon jugs.
Fix-A-Flat is another tire sealant that’s sold in US stores. The single can comes ready to use with an inflation tube that you hook up to the valve stem.
Once the tube is connected, just add the sealant by pressing down on the trigger. Fix-a-flat has changed its formula many times over the years, but the most important changes are they offer a non-flammable formula and a supposed TPMS safe version.
A new age tire sealant company, called TireJect, attempts to take a modern approach to tire sealant. While mainly used for ATV’s, TireJect also sells a vehicle tire sealant called TireJect Tire Sealant.
This sealant promises to be different by using a new, patented formula. TireJect has many different cases and variations of the amounts you can buy ranging from single pouches to one gallon jugs.
I’ve never heard of a driver adding tire sealant to a flat tire and feeling totally confident in the tire’s performance after adding it. They are usually left wondering if it’s working, or how long until it blows up. Speaking of which, if you add tire sealant to a tire, and eventually get around to plugging the tire, watch out!
When you ream the puncture, friction between the reamer and the cords can cause a spark, which ignites the liquid causing a large explosion.
Tire sealant is an outdated solution to a very dated problem. When cars were new in America, tire sealant was the bees knees. But now, it’s a liability and a hassle.
If you use sealant on a flat tire, and go to get it repaired, you might be denied service. If you take it to an independent shop that doesn’t have to follow company guidelines, the mechanic will not be happy about having to wipe out ounces of tire sealant just to patch a tire. So yes, you can drive on a tire inflated with tire sealant, but only for a very short amount of time. Doing otherwise is considered dangerous and reckless.
About THE AUTHOR
Christopher Sparks has been servicing vehicles since 2012. After completing the automotive studies program at Camden County College, he was awarded an Associates's Degree in Applied Science. His first job was a lube-tech at Jiffy Lube, and is currently an independent B-Technician servicing vehicles for the United States Postal Service. Christopher is ASE certified and loves rebuilding engines.Read more about Christopher Sparks