We all know that Western Star fans already have the facts about 18-wheelers down solid, but we’re sure you have at least one friend or family member that looks a little confused during truck talk. Let them in on these interesting truck facts to be sure they’re ready for your next big rig conversation.
Without any overweight or oversize permits, you should be maxed out at 80,000 lbs, or 36,287 kg. That’s 40 tons! Compared to the average 5,000 lb. car, that’s some heavy hauling!
US weight per axle: Steer: 12,000 lbs; drives: 34,000 lbs; trailer: 34,000 lbs.
Canada weight per axle: Steer: 5443 kg; drives: 15,422 kg; trailer: 15,422 kg.
Depending on the cab you’re driving, the average length from front to back will greatly vary. The cab length is measured from the center of the rear wheel to the center of the steer. The overall tractor trailer average is 70-80 ft. long. In Australia, “road trains” can have four trailers and weigh in at about 300,000 lbs!
Size & Weight: Semi engines are up to 6 times larger than car engines.
Horsepower and Torque: Semis average 400-600 horsepower and 1-2 thousand ft. lb. of torque. Car engines average 100-200 horsepower and 100-200 ft. lb. of torque.
Miles: Semi engines are designed to go 1,000,000 miles before an overhaul or rebuild. Car engines last about 15ok-200k miles.
Oil: Semi engines typically hold 15+ gallons of oil, while car engines take about 4-6 quarts of oil.
Length of Time Needed to Stop
Compared to your average car, you’re looking at about 40% more time needed to stop your rig. Load weight, bobtailing, and road conditions are all factors to consider.
When you’re driving without your trailer attached, that’s bobtailing. This can be dangerous in wet weather, but must be done sometimes.
A jack-knife accident is when the tractor is contacted by the trailer “coming around” on the driver. It is said that once the trailer exceeds a 45-degree angle, compared to the tractor, the jack-knife is inevitable.
This can be caused by many things and happens when the trailer wheels start to skid and actually ends up moving faster than the cab. It usually happens on icy or wet roads, but it can also happen on dry roads when the trailer is empty and the driver has to do some very hard braking.
The fifth wheel on an 18-wheeler is a round plate above the drive tires that hooks the trailer to the tractor.
A kingpin is a heavy metal cylindrical pin that is located underneath the front end of the trailer. It is that piece on the trailer that locks into the tractor. It is typically positioned 18″-48″ from the trailer nose.
A greased metal grid plate surrounds the kingpin. This grid plate allows the fifth wheel to slide underneath the trailer. When the tractor is backed into the nose of the trailer, the fifth wheel pivots and slides underneath the trailer’s grid plate. The fifth wheel then locks onto the trailer’s kingpin.
For More Information
For a look at a more detailed infographic of the information above, click here. Also, if you have any other cool and interesting facts you’d like to share about your rig, please share them in the comments section below!