Standard Trailer Hitch Installation, Classes and Sizes

Trucks towing trailer in Iceland

Trailer hitches add functionality to your vehicle.

They can be used for mounting or towing all sorts of things…

  • Bike Rack
  • Trailers
  • Campers
  • Teardrop Trailers
  • Caravans
  • Motorcycle Carrier
  • Boat Trailers
  • Lumber Carriers
  • More Cars
  • Hose Trailers
  • Cargo Trailers
  • Flatbeds

We’ll cover receiver trailer hitches: the five classes, functions, and uses. We will also explain trailer hitch installation.

Do you have the right receiver? Wondering which to buy? You’re in the right place!

This post does not cover all tow and trailer hitches—only the receiver part of the hitch.

Often the terms trailer hitches, tow hitch, and tow bars are used to refer to the whole system. The receiver is the piece that connects to the chassis.

What Is A Receiver Hitch?

It is the piece connected to the frame of the vehicle.

Location: It mounts to the frame of the vehicle and sits under the rear bumper.

Receiver Trailer Hitch Diagram Explanation
Image credit: Rack N’ Road

The receiver is the foundation. Once installed, it can connect to a ball mount, a pintle mount, etc. Those switch out depending on the trailer. The receiver hitch stays with the vehicle.

The mount you insert couples into the trailer’s mount, which is secured to the body of the trailer by its receiver.

This piece is only the receiver (made by Curt, Class 3).

The 5 Classes of Rear Receiver Trailer Hitches

There are five different kinds, or “classes” of rear receiver hitches, each a different size and max weight.

Class Size Vehicles Towing Examples
1 – I 1.25″ Cars, Crossovers Small Trailers
2 – II 1.25″ Sedans, Crossovers, small SUVs Pop-Up Camper
3 III 2″ Pickup Trucks, SUVs Campers, Boats, Utility
4 – IV 2″ Pickup Trucks, SUVs Horse Trailer, RVs
5 – V 2″ to 3″ Pickup Trucks, Commercial Vehicles Almost Anything

There are also a variety of commercial grade trailer hitches that exceed class V. When referenced, they will be specified by size (inches) and GTW and TW (see next section).

Weights

Size matters. Weight does too. It is essential to match the tow vehicle to the trailer—otherwise there are serious safety risks.

Terminology

Tongue: the whole section of the hitch that couples together (everything between the vehicle and trailer)

GTW (Gross Trailer Weight): max weight of the fully-loaded trailer

TW (Tongue Weight): the weight of the trailer acting on the vehicle’s hitch; the downward force on the vehicle

WD (Weight Distributing): max trailer weight with a weight distribution system

WDTW (Weight Distribution Tongue Weight): max tongue weight with a weight distribution system

  GTW (lbs) TW (lbs) WD (lbs) WDTW (lbs)
Class I 2,000 200
Class II 3,500 350
Class III 8,000 800 12,000 1,200
Class IV 10,000 1,000 12,000 1,200
Class V ~17,000 ~2,500 ~18,000 ~2,500

Disclaimer: Each manufacturer has different max weights | Source

Possible Combinations

Here are some examples.

trailer hitch capacities chart
Image credit: Rack N’ Road

Tongue Weight Safety

Importance of tongue weight distribution

The trailer mount and vehicle mount must match sizes. The vehicle also must be strong enough to support the trailer.

A mismatch in either category can destroy your hitch, your trailer, and even your vehicle.

Always double-check the weight of your trailer is well-balanced, like in the video below.

https://youtu.be/w9Dgxe584Ss

Should You Get the Tow Hitch Package (When Buying a Car)?

Our answer is always yes.

Be proactive. Sometime in the future, you’ll probably need to tow something.

Whether you decide to go a on road trip and bring your bikes (with a bike carrier) or get a travel trailer, you’ll need a hitch.

Pro Tip: When choosing a tow hitch, get the largest hitch your vehicle can take—you never know what you’ll need in the future, but you’ll be as prepared as possible.

Or what if you want to rent a travel trailer, teardrop camper, or caravan. You will need a vehicle to tow it. Who knows, you may become an RVer yet!

“But wait,” you may be asking, “I already own a car without a receiver. What do I do then?” I’m happy you asked—see the next section!

How to Install A (Rear) Receiver Tow Hitch

For most cars, you can do it yourself.

  1. Order the tow hitch online from Curt (our favorite manufacturers)
  2. When possible, match your vehicle’s make and model (but don’t worry, a multi-fit receiver works too)
  3. Go here are specific make and model installation guides
  4. Go here for the multi-fit guide

Car Trailer Hitch Installation

For cars—Adam installing a receiver to his Toyota Sienna (using this hitch).

https://youtu.be/UXGElNVGV6Y

Truck Trailer Hitch Installation

This is an installation to a pickup truck with this hitch.

FAQ

What it a tongue (in the context of trailer hitches)?

The tongue part of a tow hitch is the whole section of the hitch that couples together. It’s really just everything between the vehicle and trailer, including the ball mount, pins, receiver, and everything else.

What are the different hitch classes?

There are five types of hitch classes, ranging from a maximum trailer weight of 2,000 lbs or about 200 lbs tongue weight (Class 1) to ~17,000 lbs and 2,500 lbs tongue weight (Class 5). Learn more about the differences.

What is the GTW of a trailer hitch?

GTW stands for Gross Trailer Weight. It is the maximum weight of the trailer that the hitch will be pulling.

What is the TW of a trailer hitch?

TW stands for tongue weight. It is the max weight acting on the tongue of the trailer. The tongue is the vehicle’s side of the hitch joint.

What is the WD of a tow hitch?

WD stands for weight distribution. It means the max weight of the trailer that the hitch will be pulling with a weight distribution system.

What is the WDTW of a trailer hitch?

WDTW stands for weight distribution tongue weight. It means the max weight acting on the tongue of the hitch that the hitch will be pulling with a weight distribution system.
It means the tongue weight (TW) of a hitch with a weight distribution system.

What is a receiver hitch?

The receiver (hitch) is the piece that connects to the chassis.
The terms trailer hitches, tow hitch, and tow bars are used to refer to the whole system; the receiver is only a part of the whole hitch.
The receiver is the foundation. Once installed, it may connect to a ball mount, a pintle mount, etc. Those switch out depending on the trailer. The receiver hitch stays with the vehicle.

Should I buy a car or truck with a hitch?

Absolutely!
Be proactive. Sometime in the future, you’ll probably need to tow something. Having a tow bar / tow hitch / trailer hitch already installed will save you a lot of time and trouble. If you’re curious which one to buy, read this post!

What size hitch do I need for my vehicle?

When choosing a tow hitch, get the largest hitch your vehicle can take—you never know what you’ll need in the future, but you’ll be as prepared as possible.
Even if you only plan to use it for one purpose now, that may change in the future. The receiver (the part of the hitch that connects to the chassis), doesn’t change, the extensions (depending on the trailer) do.

How do I install a tow hitch / trailer hitch / receiver hitch to my vehicle?
  1. Order the tow hitch online from Curt (our favorite manufacturers)
  2. When possible, match your vehicle’s make and model (but don’t worry, a multi-fit receiver works too)
  3. Go here are specific make and model installation guides
  4. Go here for the multi-fit guide

The End

Thanks for reading! We hope you find this helpful. If you have suggestions, content ideas, feedback or want to contribute send us a quick email at info@rvsupplyco.com.

Front of trailer with hitch
The trailer’s side of the hitch.