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Fix A Flat - 4 new tires

A recent flat due to a nail has me asking many questions. I have a hard time changing a tire myself but had multiple people tell me not to use the Fix A Flat. I was tempted to use it because have heard others rave about it. What’s the deal?

Also, is it true if I replace a single tire on my Impreza wagon that I need to replace all four due to all wheel drive? Seems silly and expensive!

I don’t know about the fix a flat, but yes, if your tires are worn much you have to replace them all at once. The AWD system needs all the tires to be about the same circumference. This is explained in your owners manual.

Fix-a-Flat should only be used if there is no other alternative, IMHO.
I say that because it leaves a huge amount of messy goo inside the tire that will inevitably cause the tire to be VERY much unbalanced, thus rendering the car undriveable at high speed.

Re-balancing that tire properly would require removing the tire from the wheel in order to remove all of that goo before balancing can actually be done. Many shops will impose an extra charge–over and above the balancing fee–for removing all of that revolting mess from inside your tire.

So–if I had cannibals rapidly approaching my disabled car, I guess that I would use F-a-F, but in other, more common flat-tire scenarios, I would simply opt to install my temporary spare and drive to a tire shop for proper repair of the flat tire. Proper repair involves removing the tire from the wheel, removing the nail or other object, and installing a combination plug/patch from the inside of the tire.

As to the other question, texases is correct, and you really need to read your Owner’s Manual in order to find out this information, as well as lots of other important information regarding the safe and economical operation of your car.

However, if you can locate a tire shop that will “shave” the tread of a new tire so that it matches the circumference of your old tires, you can simply buy one tire. I suggest that you locate such a shop now, before you are in the situation of having to locate one on the spur of the moment.

+1 to VDC’s comments.

You’ll hear a lot of myths and urban legends about Fix-A-Flat. None of which are true. It’s totally safe to use in a pinch. It won’t leave a mess inside the tire and won’t cause the tire to go out of balance.

Watch this video and it will dispel all the rumors about Fix-A-Flat


Fix a flat on newer cars can also gum up the pressure sensors.
cha-ching !

No Sale!. Matt states it won’t effect the tire pressure monitoring sensors on the wheels. Watch the video again.


Well it does, you should see some of the crap we dig off of many in this shop.
There’s no cleaning it.
The sensor has either a pin hole or a porous white pad to let the pressure in, those get plugged.

Was it a Fix-A-Flat tire sealer? Or do you know?


Fix-a-flat type products work fine it the tire goes flat in your driveway…When radial tires go flat at road speed, there is usually nothing left to inflate…

The forced sale of 4 new tires is B.S. Buy one new tire as close to the other 3 as you can find and have it “shaved” so its circumference matches the others…Many tire shops have tire truing machines that can do this…

Years ago I used some brand of flat tire seal to repair a basketball that wouldn’t hold air. I did see the sealant ooze out around the defective place in the basketball. The ball did hold air, but it dribbled like a bowling ball and was really out of balance.

Fix-a-Flat saved my butt many times when I was younger and couldn’t afford to just get a new tire. It is gooey and could gum up pressure sensors. I never noticed a balance problem after using it in a tire. If you use it correctly, I think it gets more or less evenly distributed in the tire. I think it’s a good thing to have around, but I would only use it as a last resort, as VDCdriver said. I think there was at least one model of new car in recent history that came equipped with only a compressor and a canned product like Fix-a-Flat for road emergencies—not even a donut spare. If I lived in the middle of nowhere or was in a rally race, I would definitely keep some on hand.

I did not watch the video, but I know that some varieties of this stuff are extremely flammable, or at least the gas used as a propellant and to inflate the tire is. If you have this in a tire, you should warn the tech that is going to work on it. The odds are pretty low against mishap, but if a spark is made when working on the tire, you might have the perfect air/fuel mix in there to blow someone’s face off. Some of the cans used to have peel-off stickers to place on the rim to warn anyone that would work on the tire.

The best thing you can do if you have an AWD car is to religiously rotate the tires on schedule. Even replacing 4 tires is going to be cheap compared to replacing drivetrain components, which will fail prematurely if the tires are different sizes to to wear, one being new while the others are old, etc.

 Can we sort of agree that Fix a Flat may be a reasonable choice in an emergency, but it should not be considered a replacement for replacing a damaged tyre.

Nice video - EXCEPT!!

The term “fix-a-flat” is a generic name for all spray in sealants - much like Kleenex and Xerox - and there’s the problem.

Some “fix-a-flat” products do exactly what everyone complains about. That’s because they are NOT water soluable. It’s nice that the company that makes “Fix-a-Flat” (note the caps!) is trying to correct the misconception, but they totally missed the boat with the video. They need to explain why THEIR product is different. Until they do, they will be painted with the same brush.

I only use Fix-A-Flat as a last resort. It is not a good replacement for a spare tire.

I used it a long time ago on my 84 Mercury Marquis when the product was still flammable. I warned the guy at the tire store it was in there before he checked and plugged the tire for me. He didn’t charge anything extra to clean it out.

Last year, I got a flat tire on a motorcycle for the first time, and I was caught unprepared. I used another brand’s tire product, and that was good enough to help me get the bike home and to the shop another day, where they charged me an extra $40 for having to clean up the mess when they put in a new tube.

When I go on long trips in my car, I carry two spare tires, one full sized spare and the stock doughnut spare. I picked up a spare rim at a junk yard years ago and put the cheapest new tire I could find on it.

I totally disagree with VCDriver, but I do not totally agree with tester on this. I have used the product myself and I have dismounted several tires that had also had this product put in. In the short term, it does no damage, but if it is not cleaned out, it will cause the wheel to rust/corrode as it is water based.

I had one wheel split open on me due to rust after using this stuff and didn’t take it out and dry the wheel. I dismounted two tires that had this stuff in them and both rims were so badly rusted that the new tires wouldn’t seal, that is until I RTV’d the edges.

BTW, in all cases, the brand Fix-a-Flat was used.

You guys know that shows on the Speed Channel are sponsored by companies like the one that makes Fix-a-Flat, right? That doesn’t mean Matt is definitely not telling the entire truth about FaF, but it does call his objectivity into question.

Just on first blush watching that video, that jar is not a pressure vessel, which means the pressure quickly returned to atmospheric. That won’t happen inside the tire, and so we don’t really know what the product does when in a rubber enclosure at more than 2 atmospheres.

I have used Fix-a-Flat many times, the first time was when I left it in the wheel for two years and it rusted the rim through. After that I cleaned it out of the tire after use. It never caused a balance problem. The other time was with my father in law who put it in two tires and left it there.