At present, the majority of heavy-duty trucks, trailer-trucks, and passenger buses that move the US economy are diesel-powered, including 60% of all school buses. In contrast to this, however, only a very small percentage of passenger cars or light-duty trucks such as pick-ups and SUVs have diesel engines. One reason for this is that the general public in the US remains unaware of advances made in diesel technology, and continue to regard diesel engines as dirty, noisy, and bone-jarring. To compound the situation, diesel fuel is nowhere near as readily available as gasoline, and is more expensive to boot. Thus the car owner in the US has little motivation to consider the purchase of a diesel-powered vehicle. Clearly, government policies in Europe as well as Japan that keep the price of diesel fuel lower than that of gasoline are an important element in the promotion of diesel vehicles.
The following table shows energy consumption in the US for both gasoline- and diesel-powered vehicles, together with the diesel share shown as a percentage of the whole.

Table 1. Diesel Share as a Percentage of Total Fuel Consumption (in trillions of BTU*)

* BTU : British Thermal Unit

The term "light-duty trucks," as used in Table 1, refers to vehicles with a gross vehicle weight rating (GVWR) of less than 10,000 lbs. (less than 4,536 kg), 4% of which are powered by diesel engines and generally driven by individual car owners.
The percentage of diesel-powered buses, however, at 80%, is quite high. The reason for this is superior fuel economy and durability. The ability to travel long distances between refueling stops and low operating costs are also major requirements of buses used in urban transport, and newer, compact diesel engines for buses are another factor in heightened demand. A majority of medium- and heavy-duty trucks are diesel-powered.
Next, we will discuss the various US truck categories, and the market share occupied by each class.