When an automotive wheel company develops a new model, they need to take many factors into consideration. In order to maintain an economically sound number of sales, the design must be fashionable, stylish and practical to keep up with current trends.
They must also adhere to industry strength and performance specifications. Weight can be an important factor when speaking in terms of performance. Depending on what level of performance or the strength of the wheel due to design, the choice of material needs to be taken into account. Ideally, the material used would be as strong, light and easy to cast as possible. Materials such as wood, plastic or carbon would be unsuitable because they are not strong enough, too heavy or not practical to manufacture. The only materials appropriate for making wheels for motor vehicles are metals as they are the only materials strong enough. There are several metals which could be considered suitable, steel is cheap but very heavy and because of the way it is manufactured can not be styled in a manner that is as attractive as some buyers desire. .
Although fairly expensive, magnesium wheels have many advantages. Being the lightest of all structural metals, magnesium is 75 percent lighter than steel and 33 percent lighter than aluminium. It has an exceptional strength to weight ratio, making it ideal for performance and its viscosity makes it excellent for die-casting.
In order to counterbalance the issue of the high cost of pure magnesium wheels, manufacturers use alloys comprised of magnesium, aluminium and steel.
The Enkei Intl. RC5 MAG wheel is a forged pure magnesium wheel solely for high class performance racing. The standard RC5 wheel, an aluminium/magnesium alloy, weighs 9.95kgs whereas the MAG version, with the exact same dimensions (18x10 inches) weighs under 7.2kgs. The standard version is easily available and while still relatively expensive (around $700AUD each), the pure magnesium version is the only wheel in their range which is available by special request only, as it is usually only available to professional racing teams.