Producers can build several types of trucks with a Class 8 chassis, including end dumps, bulk haulers, flatbed haulers and mixers. It takes an experienced fleet manager and dealer to specify a Class 8 vocational truck chassis that will fit the producer's unique requirements. Ever-changing variables like state laws, a new plant's design or a new market that affects the driving environment dictate changes in truck design. Some of the trade-offs the producer encounters involve driver comfort, weight distribution, performance, truck length and truck height.
The producer can increase weight capacity by adding axles, including a booster, increase axle spacing or get more weight on the front axle by setting it forward. These choices affect overall truck length, which may conflict with local overall length limits and concurrently increase wheelbase and turning radius.
Setting the front axle forward not only puts more weight up front, it increases the wheelbase, to the driver's benefit. The combination of a rear-mounted PTO and a set-forward front axle allows a longer wheelbase (and thus a greater payload), a shorter overall length, and improved driver visibility and comfort.
If a mixer chassis is lowered for greater clearance and tip-over prevention, the trade-off is reduced ground clearance, undesirable for off-road driving. The factory can raise the battery box and fuel tanks to compensate, however.
For the producer, keeping a truck running may outweigh its initial cost.
The article includes developments in specifying software that make the process less time-consuming and more cost-effective.
Keywords: truck, Class 8, chassis, weight.