TRAILERING AND TOWING GLOSSARY

TRAILERING TERMS

6-SPEED TRANSMISSION

Select Yukon, Sierra 1/2-ton and Heavy Duty models, and Savana models offer an electronically controlled 6-speed automatic transmission with overdrive and tow/haul mode. Sierra Heavy Duty models with the DURAMAX Diesel 6.6L V8 Turbo use an Allison 6-speed transmission with engine grade braking and tow/haul mode.

 

CLOSED-CARGO VEHICLES

These vehicles, like the Terrain with its best-in-class maximum second-row legroom, are built to carry both cargo and passengers.

 

GROSS AXLE WEIGHT RATING (GAWR)

This is the weight in pounds each axle is capable of supporting. The load on each axle must not exceed its GAWR. The GAWR for each GMC vehicle is displayed on the driver’s door or door-lock pillar label.

 

GROSS COMBINATION WEIGHT RATING (GCWR)

This is the maximum allowable weight, expressed in pounds, of the vehicle and trailer combination, including the weight of the driver, passengers, fuel, optional equipment, and gear in the vehicle.

 

GROSS TRAILER WEIGHT

This refers to the weight of a loaded trailer.

 

GROSS VEHICLE WEIGHT RATING (GVWR)

This number, in pounds, is the maximum amount a tow vehicle may weigh. Everything that contributes to the weight of the tow vehicle is featured in this rating, including the weight of the vehicle, driver and passengers, fuel, payload, tongue load of the trailer, weight of hitch, and optional equipment. The GVWR is displayed on the driver’s door or door-lock pillar label of each GMC vehicle.

 

HIGH-QUALITY HEADLAMPS

GMC vehicle headlamps are designed to provide strong low- and high-beam output for confident driving at night and during inclement weather conditions.

 

HILL-START BRAKE ASSIST

This feature senses potential “rollback” when braking on an incline, and then holds full brake pressure when the driver releases the pedal. It allows the driver an extra 1.5 seconds to apply power and pull away. This peace of mind is standard on select GMC models.

 

INTEGRATED BRAKE CONTROLLER

Select Sierra pickups and Yukon models offer an optional trailer-brake controller. It’s completely integrated within the vehicle’s electrical and antilock braking system, allowing the trailer’s brakes to operate simultaneously with the vehicle’s.

 

OPEN-CARGO VEHICLES

Open-cargo vehicles, like the Sierra, are engineered for carrying large loads.

 

RANGE SELECTION MODE

This feature allows drivers to select the desired range of gears for the driving conditions. For example, in hilly areas the gear range can be limited to 2nd, 3rd and 4th gears. This feature is enabled with the column shift lever and can be used with cruise control and the tow/haul mode.

 

REAR-VISION CAMERA SYSTEM

The optional Rear-Vision Camera system helps make it easier to back up and align the vehicle’s hitch to the trailer. The system uses the rearview mirror display or the available in-dash navigation screen to help the driver see exactly what’s behind the vehicle.

 

“SMART” EXHAUST BRAKE

The new diesel exhaust brake is an innovative standard feature for DURAMAX models. Unlike the traditional “on/off” diesel exhaust brakes, the driver-selectable “smart” brake varies negative torque needed, based on the truckload and grade. This helps reduce brake fade, extends brake life, and gives drivers plenty of confidence when hauling heavy loads downhill.

 

TONGUE (OR HITCH) WEIGHT

The tongue weight is the total amount of trailer weight that is pressing down on the trailer hitch. Keep in mind that overall tongue weight is affected by the way the trailer is loaded.

 

TOW/HAUL MODE

An innovative tow/haul mode gives automatic transmissions on select models a dual-mode shift program. This feature raises upshift points to use more of the engine’s power for strong acceleration and raises downshift points to help slow the truck using engine braking.

 

TRAILERING MIRRORS

Heated, manually extendable, power-adjustable mirrors with turn signals in the glass are available for Sierra and Yukon XL 3/4-ton.

 

TRAILER SWAY CONTROL

On single-rear-wheel Sierra models and Yukon 1/2-ton models, this system works with StabiliTrak to minimize trailer sway by applying vehicle and/or trailer brakes. (Excludes hybrid models.)

 

TRAILER WEIGHT RATING

The trailer weight rating for any vehicle is determined by subtracting vehicle weight from GCWR. At the trailer weight rating for a properly equipped vehicle, a driver should be able to accelerate and merge with traffic, climb typical interstate grades at highway speeds, have control on varying road surfaces, and stop adequately within a reasonable distance.


DRIVE TYPES

ALL-WHEEL DRIVE (AWD)

Great for trailering over wet or snow-covered roads on a regular basis, AWD distributes power to the front and rear axles. It’s available in the Yukon Denali, Yukon XL Denali, Sierra Denali, Acadia, Acadia Denali, Terrain, Terrain Denali and select Savana models.

 

FOUR-WHEEL DRIVE

This option provides the driver with outstanding traction on demand. When set in Auto 4WD mode, AutoTrac detects wheel slippage and automatically transfers torque to the front wheels. Four-wheel drive is available in most Yukon, Sierra, and Canyon models.

 

REAR-WHEEL DRIVE

The addition of cargo increases weight on the rear wheels, which increases traction. Rear-wheel-drive vehicles typically have lighter chassis weights, resulting in better fuel economy7 than AWD and 4WD vehicles. The lighter chassis also allows more of the vehicle’s load-carrying capacity to be dedicated to cargo weight.8 Increased cargo weight also results in increased traction. Rear-wheel-drive models are available on most Sierra, Yukon, Canyon, and Savana vehicles.