Towing capacity: where to find each number

The SAAQ recommends checking load and towing capacity from the label affixed to the vehicle or the owner's manual. It also points out that the weight of occupants and luggage, and the load the trailer transfers to the hitch, eat into the vehicle's load capacity, and that each axle's limits must be respected. The hitch itself also has its own limit. An advertised “up to” capacity therefore never replaces these checks on the actual vehicle.

The GVWR, gross vehicle weight rating, is the maximum permitted weight of the loaded vehicle: its curb weight, plus occupants, plus cargo, plus the weight the trailer puts on the hitch. The GAWR, gross axle weight rating, limits what each axle can carry. The GCWR, gross combined weight rating, covers the vehicle and trailer together.

Payload is what is left once the vehicle has been weighed empty. Finally, hitch capacity belongs to the installed hitch itself, regardless of what the vehicle would allow. These five values coexist, and the most restrictive one decides.

This is where confusion most often arises. The GVWR and the maximum axle loads appear on the compliance label affixed to the driver's door jamb. The GCWR and the towing capacity, on the other hand, are not there: they come from the selection tables in the towing guide published by the manufacturer, according to the vehicle's exact configuration.

The Ford Canada towing guide illustrates this layout well, selection tables included. Not every manufacturer publishes an identical document: check the official documentation for the specific vehicle — towing guide, owner's manual, capacity chart, or confirmation obtained from the VIN.

Note as well that an owner's manual generally covers every configuration of a model year. You therefore need to find the line matching the engine and drivetrain of the vehicle you are looking at, rather than keeping the highest value in the table.

When an advertisement states a towing capacity “up to” a certain weight, or a “maximum capacity”, it refers to the most favourable configuration offered for that model. Two vehicles of the same year, wearing the same name, can therefore differ noticeably depending on their engine, their drivetrain and the presence of a factory tow package.

The assumptions used to establish a capacity also vary from one manufacturer to another: the Ford guide cited above spells out its own, including the number and weight of occupants taken into account. Two advertised capacities are therefore not always directly comparable.

Passengers, luggage, accessories and the load the trailer places on the hitch ball all count toward payload. On a family trip, it gets used up fast — and it sometimes becomes the constraint before the advertised towing capacity does.

The calculation may seem counterintuitive: start from the available payload, subtract the real weight of the occupants, subtract the luggage, and see how much payload remains available for tongue weight. Remember too that the label gives rated limits: actual weights are checked on a scale.

Tongue weight is the portion of the trailer's weight that rests on the hitch. Manufacturers give a recommended range, expressed as a proportion of the trailer's weight. Straying from it affects how the rig behaves: too little weight encourages sway, too much loads down the rear of the vehicle.

It is the distribution of the load inside the trailer that determines this value. It is measured, not estimated.

Hitches are classed by the load they accept, and the class installed can be lower than what the vehicle would allow: it then becomes the limit. Check the label on the hitch itself, not just the presence of a ball.

Beware of a common belief: the presence of a wiring harness or a transmission cooler does not by itself change the permitted capacity. Only the configuration recognized by the manufacturer, as it appears in its towing guide, determines the applicable rating.

Finally, road regulations govern trailer brake requirements, among other things. The SAAQ devotes a page to driving a light vehicle with a trailer, which covers towing capacity, load, hitch and braking. Get your information there rather than relying on a threshold heard elsewhere.

Five checks. The compliance label for the GVWR and axle loads. The manufacturer's towing guide for the GCWR and the capacity, on the line matching the configuration. The actual engine and drivetrain. The presence of a factory tow package rather than an added hitch. And the condition of the hitch: corrosion, play, legible label.

For everything else, our pre-purchase checklist applies in full, and our ranking of affordable used pickups presents the candidates by category.