Why 18-wheelers drive more slowly

Commercial tractor trailers have evolved in the last twenty years beyond the simple beasts they once were. In the old days, trucks were hulking monsters billowing black smoke and rumbling down the road, shaking the pavement as they rolled by.

Todays eighteen wheelers have some of the most advanced technology available, computerized engine management, twin turbos, modern emission systems, automatic transmissions, and air ride suspensions. But even with light weight aluminum bodies and modern aerodynamics, the biggest expense for trucking companies is still fuel.

Skyrocketing diesel costs has led most major transportation companies to use “governors” or “limiters” on their engines. The largest companies keep those governors set usually between sixty two and sixty eight miles per hour.These slower speeds keep costs down and in many instances increase safety.

Another strategy is to lower the “horse power” rating of the engines. This is accomplished through the computerized engine management system. This however, has the effect of much slower speeds while climbing hills, and slower acceleration in general.

Transmissions and rear-end gear ratios also play a roll. Since heavy trucks are made-to-order at the factory, these specifications vary greatly. Companies will “spec” these trucks according to their various needs and nature of their business.

With new congressional laws on the horizon, owner operators also will have to contend with governor regulations. Soon we will see an entire nation of trucks governed around sixty five. Independents will have little choice but to comply, or risk loosing their “authority” or right to transport goods “interstate”.

Lower governors usually mean less “momentum”, momentum allows heavy trucks to maintain speed over hilly terrain. This allows a higher average rate of speed that would otherwise be far below the speed limit.

These issues, combined with the massive weights trucks carry, (around eighty thousand pounds or forty tons), will contribute to the “slowing” if the nations highways in the coming years.

About the Author…

Eric Lorence was a “long haul” truck driver for twelve years before leaving the industry to start various internet businesses and engage in other pursuits.
Visit his Home Page at ZENTRUCKING.COM

Read More Articles Here: Thought Search Articles