Alloy wheel technology was given birth as the thirst for speed for hot rodders and later muscle car enthusiasts were encouraged by reducing their vehicle's weight. Today, alloys wheels benefit from advancements in manufacturing techniques and abundance of unfinished aluminum. Served by automakers and a gigantic aftermarket, the new generation of performance-savvy motorists have endless design choices for alloy wheels to accentuate any car, truck, or SUV.
What is an alloy wheel?
Formed from either aluminum and magnesium, the term alloy defines the process of combining other raw materials to engineer a specific designer performance metal. Popularized in the 1960s with magnesium alloy or “mag" wheels, the wheels are attributed to ultra-low weight were also prone to flammability and poor corrosive resistance. Today, while the majority of alloy wheels are made of more stable aluminum, “mag wheels” is sometimes inaccurately used as a generic slang to all alloy wheels.
Like steel wheels, alloy wheels can be formed by either casting or forging processes. Casted alloy wheels are the most widely available and bares a low cost. While many casted alloy wheels are produced by high-quality manufacturers, variables within the casting process can eventually result in weaknesses in the wheel's construction. Forging alloy wheels involves pushing alloy metal with tons of high pressure under 900 degrees Fahrenheit to a desired shape and size. The end product through forging is a lighter, stronger overall wheel shape, but at a premium price.
Advantages of alloy versus steel wheels
Selected by manufacturers for economical reasons, steel wheels are the standard type wheel sold on high-volume vehicles. While stock steel wheels perform adequately for everyday driving, alloy wheels overall performance is superior.
A vehicle's wheels, tires, as well as some suspension and drivetrain components exists as unsprung weight. Unsprung weight contributes to the ride quality and traction in high-speed conditions. With an identical wheel design, an aluminum alloy wheel weighs one-third less than a steel equivalent. The lighter alloy wheels improves the acceleration and braking by decreasing the amount of unsprung weight. As well reducing the vehicle's total weight, fuel economy will increase.
Apart from function, the leading draw to alloy wheels regards the aesthetic appeal. Thanks to the incredible ductility (ease of forming), aluminum alloy can be produced to an endless variety of patterns. This flexibility has opened up a large creative field for one-off designs and for large production runs.
Fathering the outright acceptance of alloy wheels, drag racing innovator Romeo Palamides began utilizing magnesium metal to develop lightweight custom wheels for racing. Since founding American Racing Equipment Incorporated in 1956, the company's Torq Thrust alloy wheel design gained muscle car and Hollywood fame. Torq Thrust custom alloy wheels rode on Steve McQueen's green 1968 Mustang in movie Bullitt over the punishing San Francisco street chase. Today, American Racing Wheels is joined by a number of aftermarket companies which includes BBS, OZ Racing, and SSR, all sporting multitudes of wheel designs. Flourishing through the sport compact or SUV product boom, the sale specialty wheel, tire and suspension components alone is worth 9.2 billion dollars in 2007 according to SEMA (Specialty Equipment Market Association).
Witnessing successes of aftermarket sources, some automotive OEMs have adopted their own line. General Motors has produced their own of custom 20 and 22 inch wheels for the full-sized trucks sold through GM dealerships. In another case, BMW-authorized tuner shop, Alpina also markets several magnesium alloy wheel designs nearly all modern BMWs. One Alpina design include the distinguishing 20-spoke wheel identical to the 1970s Alpina BMW sports car efforts.
When installing any set of custom wheels, some careful consideration will need to be undertaken. If the diameter of the custom wheel differs from the stock wheel, adjustments beyond changing tires will need to include recalibrating the dashboard instruments.
Cost of Alloy Wheels
For a large contingent of new vehicles for 2008 and 2009, alloy wheels are either optional or sometimes standard, often irrespective of the vehicle sale price. If buying alloy wheels separately several factors, (notedly construction, design, and prestige of the company) there could be a major disparity in alloy wheel prices. While some mass produced aluminum alloy wheels are available for under $100 US, other varieties can range well over $5,000 per wheel. With magnesium alloy wheels being most expensive, they're chosen mainly for premium sports cars or vehicles involved in auto racing.
This price of the alloy wheels may also attach additional costs for tires compatible with the new wheel setup.