What exactly is an alloy wheel?

Until recently, the wheels fitted by most manufacturers to their everyday cars have been ‘steel wheels’. Steel wheels are more resilient to damage, and are considerably cheaper to fit. Unfortunately they are almost always heavier, less attractive and smaller in both diameter and width than alloy wheels.

The term alloy wheels is usually given to wheels 'cast' from a mixture of aluminum which is light weight and great at dissipating heat and small amounts of more rigid metals whose presence in the 'mix' provides rigidity and helps prevent cracks propagating.

What are the benefits of fitting alloy wheels to my car?

In general, alloy wheels are lighter, more attractive, and better at dissipating brake heat that their steel counterparts. They tend to be available in standardised sizes, which means you can simply take off your old steel wheels and retrofit alloys.

Fitting alloy wheels normally reduces your car's unsprung weight — in layman's terms this means a reduction in rotating mass at the ends of your suspension components, giving you improved steering feel and greater braking response.

(Excerpts from indiatimes.com)