Q. What Are the Different Methods of Making Wheels?
A. In today's marketplace, two wheel materials are most common, steel and aluminum. Steel wheels are made in two pieces; the inner piece (called the center) that bolts on to the car, and the barrel (or outer) which receives the tire. The two pieces are welded together to form the wheel. Most original equipment wheels are made this way, and so are many after market wheels—especially for trucks. Steel is a durable and less expensive material.
The other material, aluminum, is by far the most popular type of wheel we sell. Its light weight, superior heat dissipation and seemingly endless design variations make it the material of choice for most buyers. Aluminum wheels can be manufactured in many ways, and each method offers advantages.
• One-piece Cast Wheels
A cast wheel is made by pouring molten aluminum into a mold; the metal then takes the mold's shape as it cools and hardens. There are three types of casting methods, low pressure/gravity, counter pressure, and high counter pressure molding (HCM); each method has its place in today's market. A wheel manufacturer will select a particular method according to the weight, strength and finish that they have specified for that design. Naturally, the more sophisticated and costly methods produce lighter and stronger wheels but at a higher price.
• Forged/Billet Wheels
The two words "forged" and "billet" have become synonymous, but in fact the manufacturing process is called forging and the material used is an aluminum billet—a solid piece of dense aluminum. The forge, a huge machine that exerts thousands of pounds of pressure on the metal, basically presses or rolls the billet into its fundamental form. This forging is then machined to final finish. This process allows wheels to be built with much less material, allowing for lighter weight and unique designs, because the process creates a much stronger wheel than other methods.
• Multi-piece Wheels
The processes mentioned above can be combined to produce a wheel of a particular strength and weight at a particular price. For example, some wheels have a cast aluminum center, welded to a steel outer. Another type of two-piece construction features a billet center welded to a rolled outer (extruded aluminum rolled into a hoop). Still other wheels feature a split outer so that widths and offsets can be made to custom specifications. This last method is the three-piece type construction. In this type of wheel, the center which can be cast, billet or forged, is usually attached to the outer assembly by special screws or rivets.
Q. What Does Fitment Mean?
A. This term is used to refer to the physical specifications of the wheel and the availability of the sizes that will fit a vehicle. So, the fitment specifications for a particular wheel and vehicle include the bolt pattern, the offset, the wheel width and the wheel diameter. Let's say you want a particular wheel for your car; select our Find Wheel Sizes for My Vehicle section and it will guide you to the styles available and the sizes that fit.
Q. What Does FWD and RWD Mean?
A. Most wheel catalogs use these acronyms, FWD for Front Wheel Drive and RWD for Rear Wheel Drive, to sort out the wheels available for these two different types of vehicles.
Q. What Features Should I Look for When Buying Wheels?
A. First and foremost, wheels are purchased for styling the vehicle. You've got to like how they look! Second, decide on the build method and quality. The discussion of manufacturing methods above was intended to inform you of the different ways wheels are made. Choose the manufacturing method you want at the price you are happy with. Finish quality is important; demand a nicely finished wheel. Finally, decide on the price. We realize there are many tradeoffs between the various features and price and that's why we carry a wide selection of wheels for every budget.
Q. What Does Finish Mean?
A. Finish refers to the type of surface treatment a wheel is given. Machined or polished finishes are popular on aluminum wheels. "Machined" is what the wheel looks like after the last shaping procedure (usually a lathe cut) has been completed. An additional step involves passing the wheel through successively finer automated and hand polishing processes. This, of course, results in the polished finish. A chrome finish is also available on aluminum wheels, but requires three additional layers of metal treatment (copper, nickel and chrome) to be achieved. Chrome finishing can significantly increase the price of the aluminum wheel. That's where steel wheels have an advantage; chrome goes on in one simple, inexpensive step. Finally, paint goes on everything and can be applied in single or multiple color schemes. Often the powder coating process is used to apply paint, resulting in a heavy, durable finish. In today's market, wheel manufacturers combine finish methods in different ways. For example, the popular tuner type designs often feature a silver center and a machined or polished lip. The last step in many styles is to seal the wheel with a clear coat of plastic, making the wheel much easier to maintain.
Q. Should I use a Spacer or Adapter?
A. The use of spacers or adapters is not recommended. If the wheel does not properly fit your vehicle you should consider a different wheel.
Q. What Are Hub-centric Rings; Do I Need Them?
A. Most aftermarket wheels are manufactured with a center hole that will fit a wide range of vehicles. The hub-centric ring is used to fill any gap that may exist between this hole and the vehicle's hub, thus centering the wheel on the axle. If you have vibrations after installing new wheels, chances are hub-centric rings were not used.
Care and Maintenance
Q. What's the Best Way to Clean My Wheels?
A. Probably the single biggest mistake when cleaning wheels is to use super cleaners, which can contain harsh abrasives. Mild soap and warm water is sufficient for routine cleaning. After cleaning chrome-plated wheels, you can apply a non-abrasive wax or cream to prevent surface corrosion. If you have clear coated wheels, skip this step. Don't let tire cleaners come into contact with your wheels; and try not to spray cold water on hot wheels. If you go to the car wash, don't let them use steam cleaners or strong chemicals on your wheels. To brighten up your polished wheels (no clear coat) use a polishing cleaner provided by the manufacturer; this requires some real work. To sustain this great look, apply some wax to keep the weather out. When you buy a set of wheels from Discount Tire, we include an installation and maintenance checklist. If you need another copy call us at 800-707-8473.
Q. What's the Best Way to Install and Remove My New Wheels?
A. That's a job that's best left to your tire dealer. A combination of special tools and methods are used to install wheels so they deliver the performance you paid for. Initial mounting of the assembly on the vehicle requires positioning and starting the lugs by hand. Next the lugs can be pre-tightened using a hand wrench or torque stick (a tool that ensures a lug is not over tightened). The final torque setting is applied using a calibrated torque wrench. Sounds complicated, but a trained technician (like those at Discount Tire) gets this done very quickly.
Q. I Just Hit Something in the Road; How Do I Find Out if My Wheel Is OK?
A. If you have a vibration or pulling symptom, chances are you may have damaged the wheel. Again, go to the tire dealer and let him inspect your wheels. He will place each assembly on the balancing machine and check for run-out (a hop or wobble). If you have a damaged wheel, get the unit repaired immediately to avoid further problems.