Surprising Facts about Semi-Trucks
Interesting things to know about 18-wheelers
When was the last time you drove on a highway or an interstate without passing a semi-truck along the way? With more than 15.5 million big rigs currently operating in the United States, probably never. But, even though you’re constantly sharing the road with semis, do you really know much about them? Take a look at the list below for some interesting facts about 18-wheelers — some of them may surprise you.
Six big rig facts
In 1898, Alexander Winton (a vehicle maker) invented the first semi-truck as a solution to transport his cars to customers. Since then, manufacturers have made incredible technological advancements and design developments, enhancing the productivity of big rigs. Learn more about modern day heavy-duty trucks in these six facts:
- Semis use diesel fuel because it’s more efficient than gasoline
Diesel fuel is more efficient than gasoline because it contains more useable energy. According to fueleconomy.gov, only 14 to 30 percent of the gasoline used in a conventional vehicle moves it down the road. The rest of the energy is used to power the engine and accessories. Diesels typically contain 10 to 15 percent more energy than gasoline, which allows the vehicle to travel up to 30 percent farther per gallon.1 Because semi-trucks are so large (requiring more power to accelerate) and typically travel long distances (needing fuel more often), the greater fuel efficiency is necessary and can help fleets save on fuel expenses.
- Diesel fuel has become more environmentally friendly
The Environmental Protection Agency (EPA) has found solutions for reducing sulfur levels in diesel fuel to make it better for the environment. While diesel engines were previously known for producing harmful emissions such as soot (particulate matter), air toxins (Nitrous Oxide) and other pollutants, fuel is now regulated to be much cleaner. According to the EPA, diesel fuel contained more than 5,000 parts per million (ppm) of sulfur before they began regulating it. As of 2006, the amount of sulfur in diesel fuel can’t be greater than 15 ppm — this is known as ultra-low sulfur diesel (ULSD).2
- Big rig engines are designed to run nonstop
Did you know diesel engines were manufactured to run extended duty cycles? Though they can run for long periods of time, it doesn’t mean they should. For every one hour a semi-truck idles, a gallon of diesel fuel is consumed — a fact that costs the industry billions of dollars each year.3 Besides increasing fuel expenses, when a semi-truck idles for extended periods of time (like overnight), the fuel isn’t completely burning, which can lead to internal engine problems.
- 18-wheelers can have up to 18 gears
Standard semi-trucks typically have 10 gears. However, it’s not unusual for big rigs to have 13, 15 and 18 gears, too. These gears are necessary for slowing down and speeding up when hauling heavy weight on different inclines and terrains.4
- It can be dangerous to make a U-turn in a semi-truck
On average, tractor-trailers are 70-75 feet long and need at least 55 feet to make a safe U-turn. Because U.S. highways are generally only 12 feet wide, a semi-truck can’t complete a safe (or legal) U-turn. Truck drivers who attempt to make a U-turn can pose a danger to themselves and other motorists due to the number of blind spots a semi has.5
- Aerodynamic mud flaps help increase fuel efficiency and safety
Mud flaps protect vehicles, passengers and pedestrians from mud or debris that can fly off a semi’s rotating tires, but they also have other advantages. Mud flaps are also designed to improve airflow, reduce water spray (from rain) and decrease drag — all of which help improve fuel efficiency and safety.6
Curious to know even more? Check out these additional fast facts:
- Of the 1.9 million semi-trucks that operate in the U.S., one-third of them are registered in California, Florida and Texas.7
- Each year, an 18-wheeler uses approximately 20,500 gallons of fuel compared to a passenger vehicle that uses about 500.8
- In 2015, commercial trucks traveled an estimated 279.8 billion miles collectively.9
- A typical semi-truck diesel engine weighs 3,000 pounds.10
- 70 percent of American goods are transported via semi-trucks11
Have anything to add?
If you’re a fleet manager, truck driver, maintenance technician or someone who’s been around big rigs for a long time, you probably know some other interesting facts. Share them with our readers in the comments below.