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Top 5 Tire Misunderstandings

If I could educate everyone out there on just these five issues, every day would be smoother. Let’s start with:

Misunderstanding #5: Not realizing the effects of exisiting tire wear

If your car is out of alignment long enough to wear your tires unevenly, and you get an alignment, it does not heal the rubber on the tires. The good rubber on the outside of the tires do not slide to the inside and even up the tires. Your tires are still worn unevenly. Until you replace the tires, you will probably have an uneven ride, and you will still need to replace the damaged tires.

The good news is, you have fixed the problem, and your symptoms and damage will not get worse. Your tires will wear at an even rate, across the span of the tread. If your tires are worn down to 4/32" on the inside, and have 10/32" on the outside, then at a normal rate of wear your tires will wear down to 3/32" on the inside when there is 9/32" on the outside. Then 2/32" on the inside when there is 8/32" on the outside. See, it is evenly wearing. The damage is already done, and you still need new tires, but you have stopped the problem from continuing on an uneven path.

Misunderstanding #4: Not knowing the difference between a patch and a plug

Maybe it was before my time, but most people seem to ask for a tire plug if they have a damaged tire, and it's something we do not do and I have never done on any car I've ever owned. Lots of people seem to ask for it though, so maybe I'm the crazy one, but it seems to me to be very unsafe to plug tires. We won't do it in our shop and as many times as I've explained that to people, more often then not they say, "Yeah, no one does that any more."

A few thoughts ... if this method is falling out of favor, maybe there is a reason? Either technology, lawyers, or education has made that method obsolete. I do know that we have dealt with the end result of a failed tire plug on a regular basis - it usually involves a tow truck, a destroyed tire, possibly a destroyed rim, and if you are really unlucky and as I've seen a few times, a destroyed axle, damaged trailer, and/or sudden unscheduled landing off the road resulting in a bent steering rack or worse.

A tire plug is an object that is sticky and expandable and gets stuffed in a hole in the tire from the outside and is wedged in until the air stops leaking out. The plug will stay intact for long enough for you to re-inflate the tire and get safely off the road at a slow speed. I have been told in some cases the plug will last for years and outlive your dog, but that's not the side of things we see in a repair shop.

We see when things go wrong, not so much when they go right, so I have no idea what the stats are for success or failure on the use of tire plugs. I do know a few things about the properties of tires, though. Speed causes heat. Heat causes expansion. The tires expand as they heat up. The plug is made of a different compound than the rubber. The plug expands at a different rate than the tire, so you will have to rely on your stuffing skills to be sure you stuffed it in there good enough and with enough gooey material that the plug will still hold when the tire expands under heat, which is speed, which means you are going fast, which means taking a chance on a failure while at a higher rate of speed often results in the above possibilities for the early demise of your tire/wheel/axle and so on. Cold things contract, think the opposite of the heat factor above, and hope that the tire is contracting at a greater rate then the plug material so you are not left with a leak and the same result.

A tire patch is a different product - patching a tire means taking it off the rim, applying a patch to the inside, sealing the patch in some way, and remounting the tire. If I had to fix a tire, I'd rather have that. If you can picture it, the hole is small, the patch is bigger than the hole. The patch is on the inside of the tire, where the air pressure is, and the air pressure is pushing the patch OUT; again, the patch is bigger than the hole, so the patch becomes a part of the inside of the tire. A tire plug is not attached to anything and is stuck in the hole, with the air constantly trying to push it out, and the road pushing it back in, so it's a matter of who wins ... the air under pressure trying to find the path of least resistance, or the weight of the vehicle pushing down on the tire as the tread meets the road and pushes the plug inward, or the stickiness of the seal it makes with itself and the sides of the hole in the tire. Who wins? Hope you back the right horse on that one.

Misunderstanding #3: Using Fix-A-Flat

This is great stuff to use if you have an emergency, are not in a position to put your spare tire on, and absolutely have to get out of the road. It will save you at a moment when you most need it. They have done a great job of advertising this stuff, but they have not done any job at all of educating people of what happens AFTER you use this on your tire.

Think about what this product does - it is a liquid that shoots out under pressure in your tire, finds the hole, seals it, and holds air while you drive. If you are familiar with the proces at all, you must have an understanding that it is a liquid when it comes out of the can, but it seals a hole.

How does liquid seal a hole? Well, liquid does not seal a hole, solids seal a hole. When it is sealing the tire, it is not a liquid. The air pressure of the hole forces the liquid towards the hole. Then as it makes contact with the air, a chemical change occurs, and it starts to harden. As it hardens, it becomes dense enough to seal off the escaping air. It changes.

Now you have a chemical reaction going on inside your tire. It was one thing, now it becomes something else. You have now started a chemistry experiment inside your tire and it will not stop with the sealing of the hole. What happens next is the liquid, as it is being forced around the inside of the tire and starts to harden, will harden in whatever shape it takes as the air hits it. Which means, you have now changed the shape of the tire itself, which means you can forget about ever balancing that tire ever again.

This chemical will continue to react with any substance it is touching - your wheel, your valve stem, your tire. Leave it in there long enough to cure and you will need a new tire at a minimum, because it adheres to the rubber, then begins to soften and consume the rubber. Then it consumes the paint and finish on your wheel, which can mean you can forget about ever getting a tire to seat to the bead again because the diameter of the bead has changed, and you might also never be able to get a valve stem to seat properly and hold a seal ever again, because it will eat at the finish and change the diameter of the hole where your valve stem goes.

Fix-A-Flat and similar products will save you when you need it, but it is not a tourniquet to stop the bleeding - it is more like an amputation. Be ready to replace at least the tire, to pay for the tech to clean the crap off your wheel, and if it was in there long enough, to replace the wheel.

Misunderstanding #2: Not knowing the purpose of a balance

Are you getting a vibration that comes and goes depending on the speed of the vehicle? If so, that is probably a balance problem. Possibly a bad tire or a loose part of some sort, but if it comes and goes, it is best to start with a balance. Maybe you parked near a curb and accidentally scrubbed off a wheel weight without knowing it. Or, maybe not.

There are many people who walk in and automatically ask for a "rotate and balance" when they do not have a balance problem. I'm not sure if it's just a term they are used to hearing, but if your tires are not out of balance, why do you want to pay someone to balance them? If you are not getting a vibration, you're just paying a tech for some exercise and getting nothing out of it yourself. You just needed a rotation.

Re-balancing a tire that is already mounted involves taking it off the car, plucking off the wheel weight (that was perfectly good and functioning as it should), putting the tire on a machine, the machine telling the tech to put another wheel weight back on, the tech putting a wheel weight back on in the same spot they just plucked one off of, and putting the wheel back on your car. There. That'll be $40 (or whatever) please. You have new wheel weights that you didn't need, and balanced tires, which were already balanced, we just did the same thing and accomplished nothing but threw away perfectly good wheel weights and wasted your time and money.

Misunderstanding #1: Not understanding a wheel problem vs. a tire problem

No matter how beautifully we mount and balance a tire, no matter what the quality level of the tire we sell you, no matter how much you spend, if you have dented or uneven wheels, they will not balance.

Your tire shop can not help you if you have hit everything but the lottery with your car over the 100,000 miles you've been driving it, and your wheels are not round any longer. Worse, you may have constant leaks and be losing air from unevenness due to the tire never seating right at the bead, or hairline cracks in the wheel losing air, or a dent near where the valve stem goes causing the valve stem to continually dislodge slightly and lose air, which will then ruin your new tires. You need to go to a service that will straighten, weld and fix wheels first, then get your new tires re-mounted. New tires will not stop the jarring, the vibrations, the leaks.

Alloy wheels seem to be softer and more susceptible to this than the basic steel wheels (steel wheels are cheaper — you can get replacements for around $25 each at junkyards, and re-use your wheel covers so they don't look any different from the outside), so if you have a lot of miles on your car or just seem to be a magnet for every pothole in the road, you might suddenly find you will get a better riding car by having a service straighten and fix your wheels once every few years.

Typically it can run anywhere from $75 each for a basic straightening to $150 each if it involves layered painting and welding the wheels. I've seen a wheel that looked as if Cookie Monster had mistaken it for a Snickerdoodle and it was welded, painted and straightened for $150 and looked new again.

This confusion between a wheel problem and a tire problem is something I see every day, especially in cars with over 100,000 miles and alloy wheels, and it can also be hard to discover because often the problem isn't obvious until the damage is apparent.

Avoiding these and other misunderstandings

I can often understand why there is a disconnect between what a customer thinks he is buying and what he actually is buying; a lot of it is the terminology used in tire stores. We are in that business, you are not, so we are the ones who are expected to know the definitions of the repair terms. On the other hand, you are the one telling us what to do, so if you tell us the wrong thing to do, is that our fault? How much do you want to be interrogated at the front counter as to the problem you are trying to solve?

Every customer has their own internal scoring mechanism for how well he understands a certain subject, how much explaining he feels he needs to do, and what end result he feels he should get for his money. I wish everyone would walk in the door, tell me the problem they want solved, and hand me the keys. Often people walk in the door, ask for a service that they feel they want, and do not explain why they want it. They may be knowledgeable enough to realize this is right service — or they may not be.

The best way to avoid a misunderstanding is to explain the problem you are trying to solve to the tech or service writer, and explain the result you hope to get. It will avoid disappointment and hard feelings if you are clear what you want to occur as a result of the transaction, and you'll get better service. Good luck!

— Beth

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