What engines do trucks use?
A truck is a motor vehicle that transports cargo from one place to another. Trucks vary greatly in configuration, size, and power. Most smaller trucks are mechanically similar to some automobiles.
Commercial trucks or lorry are large and powerful. They include firetrucks, suction excavators, concrete mixtures, refuse trucks, tractor, and straight trucks.

What are the different classes of trucks?
Trucks are classified base on the Gross Vehicle Weight Rating (GVWR). GVWR indicates the maximum truck weight and load a truck can carry. It includes truck’s weight, plus the cargo, fuel, passenger, and even the trailer tongue.
The GVWR determines the vehicle class and the regulations it has to follow. The type of driving license determines the vehicle class you are allowed to drive. There are three main categories of trucks:
- light-duty trucks
- medium-duty trucks
- heavy-duty trucks
1. Light-duty trucks
Their GVWR is less than 10,000 lbs or 4536 Kgs.
Class 1
They include a sports utility vehicle (SUV) or Sedan and have a GVWR of not more than 6,000 lbs or 2722 Kgs.
Class 2
They include utility van and have a GVWR of 6,001 – 10,000 lbs or 2722 – 4535 Kgs.
Class 3
They include a minibus and have a GVWR rating of 10,001 – 14,000 lbs or 4,536 – 6,350 Kgs.

2. Medium-duty trucks
Their GVWR range from 14,001 – 26,000 lbs
Class 4
They include a step van and have a GVWR rating of 14,001 – 16,000 lbs or 6,351 – 7,257 Kgs.
Class 5
They include a bucket truck and have a GVWR rating of 16,001 – 19,500 lbs or 7,258 – 8,845 Kgs.
Class 6
They include a school bus and have a GVWR rating of 19,501 – 26,000 lbs or 8,846 – 11,793 Kgs.
3. Heavy-duty trucks
Their GVWR is higher than 26,001 lbs or 11,794 Kgs.
Class 7
They include a city transit vehicle and have a GVWR rating of 26,001 – 33,000 lbs or 11,794 – 14,969 Kgs.
Class 8
They include a refuse truck and have a GVWR rating of above 33,001 lbs or 14,969 Kgs.
What are the different types of diesel engines?
Most modern trucks use diesel engines. Some small and medium trucks in the US, Mexico, and Canada use gasoline engines. Diesel engines gain energy by burning the fuel sprayed or injected into the compressed, hot air charge in the cylinder. There are two main classes of diesel engine: two-stroke and four-stroke
Trucks use different kinds of diesel engines. Some of the common types of diesel engines include:
- CAT Diesel
- Cummins
- Detroit Series 60
- Volvo

They are categorized based on different characteristics. Below are some of the
common ways of categorizing diesel engines:
1. By number of strokes
- Two-stroke cycle
- Four-stroke cycle
2. By power output
- Large > 750 kW
- Medium 188 – 750 kW
- Small < 188kW
3. By connecting rod and piston
- Double-acting piston
- Trunk piston
- Opposed piston
- Crosshead piston
4. By cylinder bore
Commercial vehicle and lorry engines: 90…170 mm
Passengers car engine: 75…100 mm
Medium-speed engine: 240…620 mm
Low-speed engine: 260…900 mm
High-speed engine: 165…280 mm
5. By engine speed
Slow speed engine (less than 300 rpm)
Medium-speed engine (300 to 1,000 rpm)
High-speed engine (above 1,000 rpm)
6. By cylinder arrangement
The physical arrangement of the cylinders, whether inline (straight), V, or flat (boxer).
Advantages of buying a diesel truck
There are several reasons why one would opt to buy a diesel truck rather than a gasoline car. Some of these reasons include:
1. Diesel engines are highly efficient
The combustion process in diesel engines is a lot of leaner, meaning it does not have to burn much fuel to power the truck. Diesel engines are also more energy-rich and use less fuel compared to gasoline engines.

2. Less maintenance
With a diesel-powered truck, you don’t have to worry about distributors or spark plugs. Regular maintenance, such as changing the oil, will help increase the life span of your engine. Diesel engines are more technologically advanced than gasoline engines. Only certified mechanics should service your engine.
3. Greater torque
Diesel engine emits more energy compared to gasoline engines. A diesel engine is the best if you are planning to get an engine that is strong enough to haul heavy loads or towing a trailer regularly because they have a greater amount of torque.