What Is a Tow Bar? | The Rigid Link For Flat Towing

If you have ever seen a car rolling down the highway behind a motorhome, you have watched a tow bar at work. It is the steel link that turns the towed vehicle—often called a “dinghy”—into a trailer that happens to have its own wheels. The bar transmits the pulling force from the RV while its pivoting arms allow the car to turn and ride over bumps without binding or damaging either vehicle.

In North American usage, the term overlaps with “tow hitch,” but a tow bar is specifically the bar assembly used for vehicle-to-vehicle towing, not the receiver on the back of the tow vehicle. Merriam-Webster defines it simply as a bar for towing, and CURT’s flat-towing guidance describes it as the connection between a vehicle and an RV for flat towing.

What Does A Tow Bar Do Differently Than A Trailer Hitch?

A tow bar is not a trailer hitch, a trailer tongue, or a recovery-strap anchor. It has one job: connecting one vehicle directly behind another for flat towing. The assembly typically includes a shank that inserts into the receiver, pivoting arms that attach to the towed vehicle, and tabs that lock onto a base plate mounted to the car’s frame.

The key engineering feature is articulation. A rigid bar would snap the first time the car hit a pothole. Quality tow bars use a multi-axis swivel—the Blue Ox Alpha 2, for example, uses a 3-axis swivel with self-aligning auto-locking arms—so the bar can flex vertically and laterally while still transmitting the full pulling force.

Capacity, Ratings, And What The Specs Mean

Tow bars are rated by gross towing capacity, and that number is the single most important spec to check before buying. The table below compares popular models across the capacity range.

For most RV owners towing a car or small SUV, a 5,000–6,500-pound capacity bar is the sweet spot.

What Else Do You Need To Flat Tow A Vehicle?

A tow bar alone is not a complete flat-towing setup. Aftermarket installations almost always require a base plate bolted to the towed vehicle’s frame, safety cables as a redundant connection, a wiring kit for the taillights and brakes, and—for most vehicles—a supplemental braking system to help the RV stop. The base plate is the critical piece: the tow bar’s arms latch onto its tabs, so the tab width must match the bar’s attachment hardware.

Compatibility is the other half of the equation. Flat towing usually means no automatic transmissions, because many automatics cannot be towed with the drive wheels on the ground without damage. Ford’s owner-manual content includes a Tow Bar Dimensions table with measured clearance points, a reminder that fitment is vehicle-specific and must be verified before purchase. Westfalia’s installation guidance for Mercedes-Benz GLC models lists compatibility from specific production dates, and torque requirements vary from 10 Nm to 200 Nm depending on the mounting point.

If you are shopping for your first setup and want to compare the top-rated tow bars side by side, our tested product roundup of the best vehicle tow bars on the market breaks down the leading options by capacity, build quality, and value.

FAQs

Can any car be flat towed with a tow bar?

No. The towed vehicle must be explicitly approved for flat towing by its manufacturer. Many vehicles with automatic transmissions cannot be towed with all four wheels on the ground because the transmission will not be properly lubricated. Check the owner’s manual for the vehicle’s flat-towing designation before investing in a base plate and tow bar.

Is a tow bar the same as a tow hitch?

No. A tow hitch is the receiver mounted to the towing vehicle’s frame, typically a 2-inch square tube. A tow bar is the rigid assembly that inserts into that receiver and connects to the towed vehicle. The two work together, but they are different components with different purposes.

How much weight can a tow bar handle?

Recreational tow bars are typically rated between 5,000 and 6,500 pounds. Harbor Freight’s adjustable model and the VEVOR bar are both rated for 5,000 pounds, while the Blue Ox Alpha 2 is rated for 6,500 pounds. Military-grade bars like the HDT FMTV can handle far more, up to 65,000 pounds in the high-strength version.