Which Tire Slime is the Best?

TireSlime is compared to Fix-a-Flat, TireJect, and Multi-Seal in several tests.

And we looked inside the rim and tire after testing each product to look at the tire sealant and repaired area.

If your luck is better than mine, these flat tires happen at the worst possible times. Should you use a tire repair product for a temporary or even a permanent fix for off-road applications, using products like Tire Slime or Fix-a-Flat? Do they work? Do they cause damage and corrosion? Are they flammable? Well, we will do a lot of testing on these products today and see the best. We’ll test these products on these four tires and see just how well these products work.

Short Story

Best overallBest for on-road purposesWorks pretty wellNo outstanding result
Multi-Seal Flat OutTire SlimeTireJectFix a Flat

Long Story

This rim has had a lot of corrosion, and this is untreated steel. So the question is, will these products cause decay? We will test these products on this untreated metal strip and see how much corrosion occurs over the next 24 hours. Have you ever wondered what type of solids is inside these products?

We’re going to find out. Not all of the products we’re testing are designed for on-road purposes, but this product is. This is designed for both cars and trailers. Slime claims to be tired sensor safe—emergency flat tire repair, tire sealant, seals instantly, no jack needed, safe and easy.

Immediately fills tread and punctures up to a quarter-inch diameter in size. Works safely in extreme temperatures. Safe for finished metal wheels. Non-flammable and non-toxic. Cleans up with water.

I’ll use a drywall screw to poke a hole in this tire. As you can see, it’s a lot smaller than this quarter-inch drill bit. Dosage information is on the back of this label. We’ll be using 16 ounces since we’ll be using this in a full-sized tire. Could you position the valve in the upper half of the tire?

Slowly remove the valve core with a tool and cap. Allow the tire to deflate fully. Remove the object if possible. Attach the hose and squeeze in Slime. Reinstall the valve core. Just add air. Drive, stop, verify the seal, and check tire pressure. Right at 30 pounds of force. We’ll check back tomorrow to see if there’s any loss of tire pressure.

I will rotate these tires so the Tire Slime can reach the hole. Right there is where the hole in the tire is, and you can see a few air bubbles coming out. So I’m going to go ahead and face this down so the Slime can continue to do its job.

We’ll be testing the original Fix-a-Flat. This 16-ounce can is designed for a standard tire. Repair without jack or tools. Non-flammable formula. Fix-a-Flat repairs and inflates in seconds, seal up to a quarter-inch puncture and is tire sensitive and safe. For best results, move the car slightly, so the hole is in the six o’clock position.

Make sure the tire is fully deflated before use. Shake the can vigorously for 30 seconds before attaching a hose to the tire. Remove the cap, unwind the hose, and tightly screw the nozzle clockwise onto the tire valve. Hold the can upright and push the button down firmly.

The product will be activated automatically. Only when the product stops moving through the clear hose, release the button, then unscrew the hose.


There are still contents left in this can, but it’s no longer moving through the hose, so I will go ahead and disconnect it. Only if the rim is lifted off the ground, drive the vehicle immediately a short distance, two to four miles, to allow tire pressure to increase and sealant to spread evenly inside the tire.

If needed, add air up to the manufacturer’s recommended pressure. Has the tire been repaired by a tire professional within three days or a hundred miles, whichever comes first? Okay, we’re running at 30 pounds of pressure with Fix-a-Flat. Unfortunately, the Fix-a-Flat hole is still there.

You can see a lot of leakages, so I’m going to go ahead and face this downward so Fix-a-Flat can continue to do its job.

Unfortunately, the Fix-a-Flat didn’t do the job, so I will add another can of Fix-a-Flat to see if we just had a nasty can of the product. This is the Fix-a-Flat tire. It is flat right now, so we’ll come back to this. I’ll immediately add the Fix-a-Flat again before we drive the vehicle and see if it’ll work this time.

Multi Seal Tire Sealant uses DuPont Kevlar. Unlike the others we’ll be testing, this product is only designed for off-road purposes. This product claims to fix a hole up to a half-inch, while the competition’s only a quarter-inch. Claims to work for ten years, while the competition lasts only from zero to two years.

Regarding cleanup, it stays liquid and is easy to clean up with water. The competition uses latex and adhesive, making it a sticky mess.

Multi-Seal (Flat Out)
Multi-Seal (Flat Out)

Rotate the tire so the valve stem is near the top of the tire. Remove the valve stem cap. Please don’t remove the cap from this bottle. Pull on the disc on the top hat until the hose is fully extended. Tug gently to remove the disc from the end of the hose. Use the tool on the bottom of the disc to remove the valve core.

Allow the tire to deflate fully. Attach the hose to the valve stem. You can squeeze the bottle to install the sealant. Replace valve core. Inflate the tire to manufacturer-recommended pressure. Replace the valve stem cap. We’re right at 30 pounds of force with Multi Seal.

You can drive a short distance to distribute sealant inside the tire. You can see where the Multi Seal will work on this hole in the tire.

The TireJect kit includes TireJect on-road tire sealant, a sealant applicator cap, a valve core tool, and a valve stem cap. TireJect is designed to seal bead leaks and emergency tire repair up to a quarter-inch puncture.TireJect is intended for on-road highway speed tires. We’ll test this on a full-size truck and use two pouches.

TireJect only has four steps. Step one is to deflate the tire and remove the valve core. Attach the cap to the pouch. Push the hose over the valve stem. Flip open the stem of the lid. Squeeze the contents of the bag in the tire. Reinstall the valve core, inflate the tire, and drive or rotate for several minutes.

Add the red TireJect valve cap to mark the tire. Okay, we have 30 pounds of pressure right now with the TireJect wheel. It appears that TireJect has stopped the air leak. You can see the product on this tire.

Since one of our products is not designed for on-road use, I’ll go ahead and do some off-roading, and we’ll see how these products work.

Okay. After four miles, unfortunately, Fix-a-Flat is not working. It’s leaking severely, and I expect this tire to be flat by tomorrow morning. It looks like the Multi Seal did a great job. I’m not seeing any leak where the hole is at. It seems like the Tire Slime did a great job.

I’m not seeing any leaking where the spot is at. TireJect is also doing a great job—no leaking were the areas. We will check the tire pressure in each tire in about 15 hours.


Tire repair shops typically don’t like these products because it makes a mess, so at the end of this article, we will take the tires off at each one of these rims and look inside to see what things look like. Since many wheels have alloy construction, we’ll see if these products cause damage to aluminum.

A lot of spins have some protective coating. So will these products cause damage to this zinc-coated washer? While not advertised or designed to remove corrosion, can these products do some good? If these products freeze inside a tire, it could cause it to be out of balance. So do these products freeze in frigid temperatures?

A quick look at the safety data sheet for Slime. It contains glycerol, attapulgite, cellulose, and quartz. Only a little information on Multi Seal. It contains propylene glycol. For TireJect, it includes propylene glycol and natural rubber latex. So if you’re allergic to latex, this could be a problem.

Fix-a-Flat tire sealant inflater contains tetrafluoro-propene, glycerol, and cellulose. We’ll check back in 24 hours to see if these products cause corrosion.

This freezer is set to 15 below zero. We’ll see if that causes these products to become solid after they’ve been there for 24 hours. I will try to find out what is inside each of these products. I will shake these up, add them to the strainer, and see if we can filter out particles.

There are some tiny black particles inside the Tire Slime. Wow, that’s some thick pasty stuff. Multi Seal Tire Sealant is a lot gooier than Tire Slime. This stuff is vast, and the particles inside are much larger than in Tire Slime. I’m not seeing particles of anything, so I don’t know how Fix-a-Flat fills a quarter-inch hole, but I don’t see any particles that would be used to wedge into the hole.

I don’t know any particles, but I see some globs, so I’m different from how this product works. This stuff became like glue very quickly. Could you take a look at that?

I’ll go ahead and remove each of the nails from the test cups, rinse them off with water, and we’ll take a closer look at each one of them. It does not appear that any of these products removed any rust. There’s no visible damage to the zinc coating on any of these washers. None of these products seem to cause any damage to the aluminum.

Our control is only exposed to air, and there’s no visible rust. No visible corrosion with the Tire Slime. You can see the black specks. That’s normal. I will go ahead and wipe off some of this Tire Slime and get a closer look at the metal. There does not appear to be any visible rust with Fix-a-Flat.

Okay, no visible rust. The Multi Seal is drying out in some areas, and there is no rust. With Multi Seal, there’s a change in color with some of the steel. I can’t tell if this is rust, but there’s been some change.

There appears to be surface oxidation with TireJect, but I will go to clean this up with water and get a closer look. Lower on the steel, some surface rust appears to have started.

TireJect is hard to clean up. There’s still quite a bit of TireJect glued to this piece of metal. Regarding ease of cleanup, Multi Seal is the easiest, then Tire Slime, then Fix-a-Flat, and finally TireJect, because TireJect leaves a coating that doesn’t want to come up off with water.


I will open the freezer now and see if these products are frozen. Fix-a-Flat. Yeah, Fix-a-Flat… Look at that. Multi Seal didn’t freeze. It’s still like a gel. I’m very impressed. Multi _eal stayed more in a gel than Tire Slime, but Tire Slime would still seem like it would do its job. TireJect is also still in a gel-like state.

Multi Seal seems the best, TireJect second, Slime third, and Fix-a-Flat fourth.

Unfortunately, Fix-a-Flat did not fix the flat. I will see how much tire pressure is in this tire—about four pounds of force with Fix-a-Flat. The TireJect tire is a holding-pressure tire. TireJect still has 30 pounds of muscle. Tire Slime is still at 30 pounds of force. Multi Seal still has 30 pounds of force.

All these products are designed to handle up to a quarter-inch hole, so I’m going to go ahead and use a quarter-inch bolt to poke a hole in each one of these tires. Okay, this is the original hole with TireJect. I will put a little Windex on it to see if we still have any bubbling or leaking.

It appears that the gap is sealed. This is a quarter-inch bolt. I will drive this bolt into the original hole to make it larger to see if the tire jet can seal up this giant hole. The bolt is entirely in the tire. I will pull this out and see if it will seal it up.

I’ve got the hole in the tire straight down so the TireJect can make its way into the hole. The Tire Slime appears to have done a great job repairing this hole. It doesn’t seem to leak, so I will drive this quarter-inch spike into the tire. I will face this and let the Tire Slime work on this hole.

This is the original hole with Multi Seal. It doesn’t look like there’s any leaking. I’m going to put this tire back on the vehicle and drive it for about five miles, and when we come back, we’ll take these wheels off and see if they’re still leaking.

I just finished driving five miles, so that I will remove the wheel, and we’ll look closer at the hole to see if it’s still leaking. This is where the spot is in the tire. I will spray some Windex on it to see if we have any bubbling. I’m pretty impressed. TireJect did the job. It does not appear to be leaking.

You could see where the hole is at. It is a big hole. Let’s see if it’s still leaking. Okay. Tire Slime did the job—awe-inspiring performance by Tire Slime. So we’ll see if Multi Seal fully sealed up this hole. Okay. Multi Seal did the job.

I like to test manufacturers’ claims, and Multi Seal claims that their product can handle up to a half-inch puncture, so I will use a three-eighths-inch landscape spike to see if it can handle a hole that size.

I placed a sharp tip on this landscape spike, so I will try to drive it into the tire and make the hole even more significant. Now that’s a lot of damage. It will be exciting to see if Multi Seal can stop the leak. I’m going to see if I get this landscape spike out now. So is Multi Seal able to stop the leak from this landscape spike?

Absolutely. The hole is no longer leaking, and there is tire pressure in this tire.

We’ll take the tires off these rims and look inside to see what things look like. I’ve broken the bead on this tire, and as you can see, the Fix-a-Flat is oozing everywhere. So if you work at a tire shop, you’ve seen this before, and it’s probably something you don’t like too much.

You can see Fix-a-Flat is all over the rim. It seems manageable because this stuff doesn’t turn into Slime like other products. There’s still a big puddle of Fix-a-Flat inside the tire.

Okay, this stuff’s not called Tire Slime without good cause. This stuff makes a huge mess. You see the Tire Slime gradually creeping toward the bottom of the tire. This stuff tends to make a big mess. That’s where the original puncture was that Tire Slime was able to repair.

When TireJect dries, it becomes very stringy. Here’s the damage to the TireJect tire.

This is Multi Seal. As you can see, this stuff has created some slime just about everywhere, and I expect this will be messy to remove because we added 32 ounces of this product into this tire. As you can see, there’s still a lot of Multi Seal inside this tire. Could you look at the size of the damage to this tire? This stuff did a fantastic job patching up this giant hole.

Besides jumper cables, the essential tool in my vehicle is a portable tire pressure pump. These things have saved me on several occasions, and I’ve been able to help other people out as well.

The first time you use it, you’ll think that your $15 to $25 was extremely well spent, and I highly recommend carrying one of these so that you can help yourself out or help others in a time of need.



All the products tested contain just enough content to repair one full-size tire. Fix-a-Flat was the least expensive product at only $6.83, then Tire Slime at $8.99. Multi Seal and TireJect were quite a bit more expensive. Fix-a-Flat seems like the most accessible product, but TireJect was a close second.

TireJect’s small pouches are very easy to empty quickly. Multi Seal required 32 ounces into the tire, but it flowed much more accessible than Tire Slime, which took the most effort and extended time.

Ease of Use

Anyway, I had a lot of fun testing these different types of products. I always look forward to reading your comments and especially your article ideas. As usual, thanks for reading this article. Please take care, and I look forward to next time.

So is Tire Slime the best? It is the best for on-road purposes. However, Multi Seal Flat-Out seems to be an overall better off-road product. Regarding the other products we tested, TireJect works well. Unfortunately, we didn’t have outstanding success with Fix-a-Flat. Maybe it was just me. I tried four different product cans and still await good results.

Ease of Use


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