I have just read both websites for these products. They seem very similar as it appears that both can be washed out and then a permanent patch put on. Fix-a-flat, though, has it's own "air". Other than this, is there a reason to buy one or the other?

Thank you for all your help!

i have had used Slime, but it still leaked. A lot slower, but you still had to pump up the tires every one to two days.

never used the other one.

I found it to be more slime than anything. I had to stop and get just a normal tire plug on the way home after using it. The hole was not even that big. So I started keeping a tire plugging in the vehicle.

Ditto here, I don't trust the liquids, I carry a tire plug kit in both vehicles.
I have used Slime once and didn't have any problems, tire lasted quite a while, actually till the tread wore down.

The thing is, if you only carry Slime or Fix-A-Flat and the hole is to big your screwed, so my suggestion is if you want to carry one of the liquids you should also carry a tire plug kit also just in case.

I wouldn't use either one for a passenger car except in a dire emergency, but I do use Slime on my ATV. I use it as more of a preventative than anything else. I put a bottle in each tire every 3-4 years. In my experience it works well. It seems to permanently plug slow leaks, and turn regular leaks into slow leaks. It is especially good for troublesome leaks around the rim. I have never had much luck with Fixaflat. It's too watery. As others have said, you are better off getting a plug kit along with a small portable compressor.

I like fix-a-flat. Not perfect bud for around $5, its worth having one in each car. Used to carry a foot operated pump and might have to find another one to add back in.

Teacher

The products are slightly different.

Slime requires you to remove the valve core, which effectively renders the tire completely flat. Fix a flat can be used when the tire is low on air.

I also use it in my ATV tires with pretty good success.

the flat must be fix as soon as possible. The slime doesn't work for large tires. I have heard many stories of Canadians who used the slime with total failure. The slime leak out of the tire while the car in motion.

If you go with Fix-a-flat, don't let the bottle rattle around in something like a tool box. It will find some way to develop a hole in it & get all over everything near it.

I like slime, but have never used it on a OTR tire. But it works well on holes the size of nails and screws. For car and truck tires i use a plug kit, this is the kit i use.

http://www.safetyseal.com/

Very well made but a little pricey.