Any spring, whether it's a leaf, torsion or coil spring, must compensate for irregularities in the road surface, maintain the suspension system at a predetermined height and support added weight without excessive sagging. As you'll read, each of these functions is extremely important in providing comfort, precise handling and load-bearing capability in the modern import vehicle.

LEAF SPRINGS
Historically speaking, the steel multi-leaf spring is one of the oldest and most widely used spring designs in automotive suspension systems. The advantages of the leaf spring are many, not only because it acts as a spring, but also because it attaches the axle directly to the chassis. In some applications, a single "mono-leaf" spring can be used to perform the above functions. Although leaf springs are normally used in truck applications with solid drive axles, a transverse leaf spring can be combined with an independently suspended rear axle to form a lightweight rear suspension system in performance road cars.

The leaf spring can also be "tuned" to different load-bearing and ride control requirements by changing the numbers, widths, thicknesses and lengths of the spring leaves. In addition, a leaf spring tends to act as its own rebound dampener due to the friction of the leaves rubbing together. In some cases, a conventional steel spring can be replaced with a "pl...