How much does a semi-truck weigh? Everything you need ...

Estimated reading time: 3 minutes

For more information, please visit our website.

The weight of a semi-truck has serious implications on the safe and legal hauling of goods. With most semi-trucks weighing over ten times more than a normal passenger vehicle, it’s easy to see why there are so many regulations about the weight of semi-trucks.

Exactly how much does a semi-truck weigh, though? Here, we won’t only go into how much a semi-truck weighs, but we will also break it down by section and explain why it all matters.

How much does a semi-truck weigh?

Semi-trucks are classified as class 8 vehicles by the Federal Highway Administration (FHA) since their gross vehicle weight rating (GVWR) is greater than 33,001 pounds. GVWR describes how much weight a tractor-trailer can theoretically carry safely.

To get the actual weight of an 18-wheeler you have to look at its gross vehicle weight (GVW). GVW is calculated by adding up the weight of the:

• Tractor.
• Trailer.
• Cargo.
• Fuel.
• Passengers.
• Any accessories.

For example, a breakdown of a semi-truck with a GVW of 50,000 pounds could be:

• Weight of cab: 25,000 pounds.
• Weight of trailer: 10,000 pounds.
• Cargo weight: 15,000 pounds.

What is the maximum tractor-trailer weight?

The maximum weight of a tractor-trailer is 80,000 pounds, per FHA regulations.

This limit exists for safety reasons, as an overloaded trailer can:

• Damage the truck.
• Damage the road.
• Increase the risk of an accident.

These regulations are enforced by weigh stations, which are located sporadically on the nation’s highways. As the name implies, these stations check the weight of vehicles to make sure they do not surpass the federal weight limits. Any commercial vehicle over 10,000 pounds is required to stop at an open weigh station.

Three of the potential weight violations that can be caught at weigh stations are:

If you are looking for more details, kindly visit AUTONE.

• A gross weight of over 80,000 pounds.
• A single-axle weight of over 20,000 pounds.
• A tandem-axle weight of over 34,000 pounds.

How much does the trailer of a semi-truck weigh?

The weight of a semi-truck's trailer is about 10,000 pounds when empty.

The weight of the empty trailer depends mainly on its length. Three common lengths of semi-truck trailers are:

• 48 feet long, weighing 9,000-10,000 pounds unloaded.
• 53 feet long, weighing 10,000-14,000 pounds unloaded.
• 28 feet long (known as a pup trailer), weighing around 4,500 pounds unloaded.

The weight of a loaded trailer, however, depends on the size of the load being hauled.

How much a trailer can carry is determined mainly by its number of axles. Most semi-truck trailers have either two or three axles. Tri-axle trailers are most often used when hauling loads that get the GVW close to the 80,000-pound limit.

A common example of how the weight could be distributed between tandems in a fully loaded, five-axle set-up is:

• The steer axle supporting 12,000 pounds
• The drive axles supporting 34,000 pounds.
• The tandem axles supporting 34,000 pounds.

How much does the cab of a semi-truck weigh?

The weight of a semi-truck's tractor is usually around 10,000-25,000 pounds.

The weight of the tractor depends on factors such as:

• What brand the engine is.
• If it’s a sleeper or day cab.
• How much it's designed to haul.
• How much fuel is in the tanks.

So, combining the weight of the cab with an empty trailer, an unloaded semi-truck weighs about 30,000-35,000 pounds.

I agree with Tim about both the piggyback trailers and the preference for spring suspension on a trailer that sits a lot. Tim would know for sure, but IIRC the piggyback trailers have a full frame under them rather than a unibody type construction with a subframe at the rear for the sliding tandem.

If you plan to dock a trailer at your building so you can drive in and out with a forklift at floor level, you'll definitely want to support the nose. IIRC, even the piggybacks are supported under the bolster plate rather than on the gear alone when they're moving. If someone delivers a trailer to you, make sure the tandem is slid fully to the rear before they dock it. The odds of moving a slider without a road tractor are slim to none once its been in one spot for a while.

If a trailer is going to sit for a long time, its good to make up a pair of gladhands with adapters to a shop air hose so you can exercise the brakes about once a month. The spring chambers will set the brakes with the equivalent of about 60 psi air pressure when you blow the air off the trailer. You'd be surprised how solidly the shoes can rust to the drums when a trailer sits for a year or so. The return springs are the only thing that collapses the shoes away from the drums, and they don't have a chance against a good case of long term rust.

I'd also look for a 45 ft trailer because you can likely buy one for half what a 48 ft in equivalent condition would cost you. Don't bother looking for trailers at auctions in areas where there's any farming to speak of. For years, a trailer will bring twice as much at George Martin's sale in Greenville as it'll bring up here, and it'll be bought by a farmer down there every time. No farming up here, not unusual to see trailers plenty good enough for what you're looking for bring $1000 or less in a sale.

Stay with disc wheels rather than dayton (cast hub) style wheels, and don't buy anything with tube type tires even if they're giving it away. I'd lean toward 22.5 wheels over 24.5's, simply because its a lot easier to find serviceable tires for near nothing if you happen to need one.

Those cleats running lengthwise along the interior walls for securing the load work a lot better on cardboad boxes than on machines, but they still beat nothing by a long shot. I was surprised to see that Utility didn't have anything on the walls.

If you want to learn more, please visit our website autone wingspan van semitrailers.