Chevrolet Corvette 40th anniversary factory wheels, $40.

If you were trying to sell your set of original wheels from your 1993 Corvette (which, by the way, was the 40th anniversary year of the 'vette) at your yard sale, wouldn't you at least put them out in the yard or driveway, and maybe put some sort of sign on them stating what kind of car they came off, and perhaps a price? Hmmm....

But at the sale where I found these rims, all I saw was one closed 'American Racing' aftermarket wheel box on the floor in the gargage. By now we should all know how people can't resist throwing old parts into the boxes that the new parts came out of! So naturally, I had to pop this box open and look inside.

The wheel swap this Corvette owner did is one of those rare cases where the old stuff was better than the stuff that came in the box new! When I asked the owner what this rim was from, she told me it went to her husband's 1993 Corvette. She added that she had the other three wheels in the house, but didn't want to take up all the room in the garage by dragging them all out at once!

You should know that it's a very common practice to replace factory steel wheels with aluminum 'mag' wheels, because steel wheels are simply not as attractive as aluminum. However... whenever you find factory aluminum wheels for sale, you should immediately wonder why the owner replaced them. Sure, it's possible that he or she just didn't really like the look of the factory aluminum wheels.

But whenever I see aluminum wheels for sale at a yard sale, I always expect to find at least one of them to be dented or broken, due to an impact with something in the roadway, or from actually wrecking the vehicle. In cases like these, an owner will often go in search of a new wheel to replace the damaged one, only to find that one factory replacement wheel can cost more than an entire set of aftermarket wheels. He then buys four new aftermarket wheels, tosses the old wheels into the boxes his new wheels came in, and then sells the old wheels at his next yard sale. Remember this!

Of course, things aren't always so dismal. Sometimes, as in the case with these wheels, the guy just wanted something different. I carefully inspected all four of these wheels and aside from a tiny bit of curb rash, which most used wheels have, they're perfectly fine. A test I always try to do to make sure that a wheel hasn't been bashed out of its normally round configuration is to simply roll it along a flat surface, like a garage floor or driveway, and check for any wobbles or wiggles as it rolls. In my experience with aluminum wheels, I've found that damage is not hard to spot visually. Wheels are pretty tough critters, and a wheel that's suffered an impact violent enough to bend it to the point that it rolls abnormally will usually exhibit an obvious sign of impact somewhere. I've found that the best thing to do is to talk to the wheels' owner, and ask them why the rims were replaced.

Now, while we're on the topic of car wheels, here are a couple of other points worth mentioning. As you look at these wheels without their center caps, there's really no way to know what car they're from, unless you're already familiar with the Corvette. But there are a couple of indicators that will clue the observant person in to the fact that they go on something related to high performance. The first indicator is that two of the wheels (the rear) are an inch or so wider than the other two, meaning that the car these wheels fit has wider tires on the back than on the front. This wider-in-the-back feature is not something you find on your garden variety grocery getter. It's strictly high performance.

Second, notice the cool windmill pattern on the spokes. Although these spokes look nice and pretty, they serve an important function. As everyone knows, the job of a car's brakes is to stop the car. The two types of brakes used on modern vehicles are the drum and the disc. On drum brakes, a pair of stationary brake 'shoes' are enclosed inside a drum that rotates along with the wheel. When the brakes are applied, these shoes expand against the inside of the drum, braking the vehicle.

A disc brake, on the other hand, employs a small stationary brake 'caliper' that squeezes two small brake pads against either side of a 'disc' that rotates with the wheel. Whereas the disc brake is a fully exposed unit hanging right out there in the open air, all the braking in the drum brake happens inside the enclosed drum, holding in the heat. This naturally means that disc brakes are much easier to cool than drum brakes, but why is this cooling function so important?

A basic law of physics dictates that you can't simply make energy 'disappear.' The best you can do is to convert it from one form of energy to another, and that's just what your car's brakes do when they convert the kinetic energy of the moving vehicle into the heat energy of hot brakes, as they bring your vehicle to a stop. But since brakes do their job by absorbing heat, something must obviously be done with all that heat if they're going to continue to do their job of braking. When a brake becomes saturated with heat that it can't get rid of, it loses its ability to stop the car, which results in that miserable condition many race car drivers in the old days called 'brake fade,' where their overheated brakes actually felt like they'd been smeared with grease. Yikes!

As you've probably already noticed, the overheating we're talking about here is not likely to be an issue on a family station wagon or a little four-cylinder economy sedan. But on a performance vehicle, things are different. Things like traversing winding roads, where the brakes are being constantly applied, or hauling a car to a quick stop from 150 m.p.h., tend to get brakes really hot, really fast. Under circumstances like these, brakes must have the ability to unload all this built-up heat very quickly, which is where disc brakes make the difference.

So, the trick to maintaining good braking efficiency on the sports car lies in keeping the brakes cool, which brings us back to those interesting spokes on the wheels in this study. If you look at those spokes carefully, you'll notice that they're actually fan blades. That's right, as the Corvette drives down the road, those fan blade spokes suck cold air in through the back side of the wheel, across the brakes, and then blow it out the side of the car, keeping the whole wheel assembly nice and cool. This is not a feature you normally see on your garden variety station wagon wheels, but it is something you're likely to see on high-performance sports cars, so take note!

Finally, a careful look at the Corvette in the picture shows that the wheel fins have a distinct clockwise arc as they move from the hub out to the rim. But if you were to take a wheel from one side of the car and put it on the other side, the spokes would move in a counterclockwise pattern, ruining the wheel's distinctive rakish look. So, in order for this car to look the same on both sides, the wheels must be mirror images of each other. All this means that this Corvette's wheels are not only front-to-back specific, but also side-to-side specific. That's right - there's a specific wheel for each corner of the car, and you can't change them around!

I guess the moral of this story is that so many things we look at are ready to tell us more than we're able to see unless we know what we're looking at. As you peruse the world of stuff out there and see something you're not familiar with, stop and think.

It's very important to develop the habit of looking around carefully. Don't just look on the tables, but look under tables. Look in the boxes. You have to remember that sellers don't have the same goals as you. They're much more likely to adorn their tables and driveways with the low-value stuff, while allowing the stuff you know is valuable to languish in closed cardboard boxes, or worse yet, forgotten about in the spare bedroom.

These 40th anniversary Chevrolet Corvette wheels sold on eBay for $295.