Although automobiles are among the most numerous types of vehicles on the road today, other types of vehicles such as pickup trucks, vans, commercial trucks, buses, and even motorcycles make up the vehicles we see on the road every day. Since these vehicles have different weights, sizes, and applications, there is no single formula for suspension design. Of the suspension designs used today, the most evolved would be those used in luxury sports sedans and sports cars.
Drawing from beam axle and leaf spring designs that were inspired by horse-drawn buggies, modern high-performance automotive suspensions feature double-wishbone or multi-link suspension designs. These suspension components will be made of lightweight materials, primarily aluminum, which offer a much lower unsprung weight compared to stamped steel. In addition, these suspensions will be complemented by high-strength bushings, stabilizer bars and high-performance shock absorbers. High-performance car manufacturers even use dampers that contain magnetic fluids whose damping rate is electronically controlled. But again, these are cars intended for on-road use where ride quality and handling performance are paramount.
The other end of the spectrum for vehicle suspensions would be the suspensions used for ATVs. Rather than focusing on ride quality and road handling, off-road vehicle suspension types focus on suspension travel, stability, component strength, and ground clearance. Robust suspension arms and oversized long-travel shocks are practically a requirement for a vehicle to qualify as a true all-rounder. With a four-wheel drive vehicle, reliability and traction are key factors to consider, so it is not uncommon to see live axle suspensions being used regularly even today. In fact, some hardcore off-roaders turn the independent front suspensions of their 4-wheel drive vehicles into a live axle due to the strength and consistent ground clearance inherent in this suspension design. In this regard, midsize crossovers do not qualify, even if they are equipped with all-wheel drive. Some SUV manufacturers don’t even try to advertise their AWD SUVs as an off-road vehicle. Such is the case with the BMW X5.
Vehicle suspension types for utility vehicles are among the types discussed above. Pickup trucks and vans are expected to carry people and large heavy loads, and sometimes both at the same time. In this regard, the type of vehicle suspension typically used with vans and pickup trucks is an independent front suspension design with a multi-link coil spring suspension that locates a live axle at the rear. Today, some automakers offer crossover vehicles with fully independent front and rear suspensions. Despite looking like heavy vehicles, midsize SUVs using this type of vehicle suspension cannot be expected to haul or tow heavy loads.