Speak truck

4LO

A special low gear for crawling through mud, steep ramps, or pulling a boat out of the water.

Transfer-case reduction gearing (roughly 2.6:1 on HD) that multiplies torque at the wheels for low-speed traction and control.

ACC

Cruise control that automatically slows down and speeds up to keep a safe gap from the car ahead.

Radar/camera fusion tracks the lead vehicle and modulates throttle and brakes. Stop & Go variants can come to a complete stop and resume.

AEB

Hits the brakes for you if a crash is about to happen and you haven't reacted.

Forward Collision Warning with Active Braking and pedestrian detection; applies full brake pressure if the driver fails to respond to warnings.

A gearing number — a higher number (like 4.10) pulls harder; a lower one (like 3.21) saves fuel.

Ratio of driveshaft revolutions to axle revolutions. Numerically higher ratios multiply torque for towing at the cost of highway RPM and fuel economy.

How big the cabin is: Regular (2 doors), Quad (small rear doors), Crew (full rear doors), Mega (extra-long rear).

Regular Cab: single row. Quad Cab: 1500 only, reduced rear legroom. Crew Cab: full rear doors. Mega Cab: HD only, extended cab with reclining rear seats.

A truck sold without a bed so a business can add a dump box, flatbed, or service body.

Incomplete vehicle with cab and bare frame rails, specified by Cab-to-Axle (CA) dimension for upfitter bodies. Offered in 3500, 4500, and 5500 Class 3–5 ratings.

Ram's famous heavy-duty diesel engine, built by Cummins — known for torque and lasting a long time.

6.7L inline-six with cast-iron block, high-pressure common-rail injection, and a variable-geometry turbocharger. HO version rated up to 1,075 lb-ft.

DEF

A blue-capped fluid diesel trucks need to keep emissions clean. Refill it at oil changes or as needed.

A urea solution injected into the exhaust; Selective Catalytic Reduction (SCR) converts NOx into nitrogen and water.

DRW

A truck with two tires on each side of the rear axle for extra stability and weight capacity.

Dual Rear Wheel configuration, available on 3500 and Chassis Cab. Increases rear axle capacity and lateral stability for heavy fifth-wheel/gooseneck loads.

A small electric motor that helps the engine start, stop, and get moving — saves a little fuel.

48-volt belt-driven motor-generator replacing the alternator, with a small lithium-ion battery. Enables smooth start/stop, regenerative braking, and short-term torque fill.

Uses the diesel engine itself to help slow the truck down — saves your brakes on hills.

A variable-geometry turbo restricts exhaust flow, creating back-pressure that resists engine rotation and provides engine braking, especially when descending grades with a load.

Factory-installed mounting points so a fifth-wheel or gooseneck hitch drops right in.

Frame-mounted under-bed rails, a removable center ball/puck system, and a bed-mounted 7-pin connector integrated with the trailer brake controller.

A big horseshoe-shaped hitch mounted in the bed that connects to large RV trailers.

A kingpin-and-plate coupling mounted over or just ahead of the rear axle, placing 15–25% of trailer weight onto the truck for superior stability.

Gross Combined Weight Rating

The most the truck AND trailer can weigh together.

Maximum allowable combined weight of the loaded truck and loaded trailer. Often the true limiting factor when towing.

A ball in the middle of the truck bed, used for livestock and flatbed trailers.

A ball coupler mounted to the frame through the bed floor; the trailer's coupler arm arcs over the tailgate. Allows tighter turns than a fifth wheel.

Gross Vehicle Weight Rating

The most the truck itself can weigh, fully loaded.

Maximum allowable loaded weight of the vehicle, including curb weight plus payload. Set by the manufacturer based on axles, frame, suspension, and tires.

Torque is the twist that gets a load moving; horsepower is how fast you can keep doing that work.

Torque = rotational force (lb-ft). Horsepower = torque × RPM ÷ 5,252. Diesels make peak torque low in the RPM band — ideal for towing.

Ram's newer six-cylinder with two turbos — more power than a V8, better fuel use.

3.0L inline-six with dual turbochargers, direct injection, and plasma-sprayed bores. Standard Output 420 hp / High Output 540 hp.

Gently nudges the steering if you start drifting out of your lane.

Forward camera detects lane markings; electric power steering applies corrective torque when unintended departure is detected.

How much weight you can put in the truck — people, cargo, and hitch weight combined.

GVWR minus curb weight. Includes occupants, cargo, accessories, and tongue/pin weight. Exact figure is on the door-jamb Tire & Loading label.

The fifth-wheel version of tongue weight.

Vertical load on the kingpin of a fifth-wheel trailer, generally 15–25% of gross trailer weight, counted against the truck's payload.

PTO

A way to use the truck's engine to power equipment like a dump bed or crane.

Transmission-mounted gearbox provision that transfers engine power to hydraulic pumps or other auxiliary equipment, stationary or mobile.

How much of the trailer's weight presses down on the truck's hitch.

Vertical static load at the coupler, typically 10–15% of gross trailer weight for conventional trailers. Too little causes sway; too much overloads the rear axle.

The heaviest trailer the truck is rated to pull.

Maximum trailer weight per SAE J2807 testing for a specific configuration (engine, axle ratio, cab, bed, drivetrain).

ITBC

A dash control that makes the trailer's brakes work with the truck's brakes.

An integrated controller sends a proportional electric signal to trailer brakes. Gain is adjusted to trailer weight; required by law above certain weights in most states.