RV Terms

This is a Glossary of commonly used RV terms. We tried to include as many as possible, but there are certainly more terms used. Let us know and we will add them.

Glossary of RV Terms

120 AC/12 DC/LP-gas – refers to the power sources on which RV refrigerators operate; 120 AC is 120-volt alternating current (same as in houses); 12 DC is 12-volt direct current (same as in motor vehicles); LP-gas. Some RV refrigerators can operate on two of the three sources, others on all three.

Adjustable Ball Mount – An adjustable ball mount allows the ball to be raised, lowered and tilted in small increments to allow fine tuning of the spring bar setup and to compensate for tow vehicle “squat,” which occurs after the trailer coupler is lowered onto the ball.

Airbag – In RV terms, a sort of shock absorber positioned at the forward and rear axles of a motor home.

Airstreaming – Using an Airstream travel trailer as RV of preference. Towing an Airstream travel trailer.

Anode Rod – An anode rod, when used in a water heater, attracts corrosion causing products in the water. These products attack the anode rod instead of the metal tank itself. The anode rod should be inspected yearly and changed when it is reduced to about 1/4 of its original size. The rods are used in steel water heater tanks – an aluminum tank has an inner layer of anode metal to accomplish the same thing. Anode rods should not be installed in an aluminum tank!

Arctic Pack – Also spelled Arctic Pac and Arctic Pak, an optional kit to insulate RVs for winter camping.

Auxiliary battery – Extra battery to run 12-volt equipment.

Axle Ratio – The final drive gear ratio created by the relationship between the ring and pinion gears and the rotation of the driveshaft. In a 4.10:1 axle ratio, for example, the driveshaft will rotate 4.1 times for each rotation of the axle shaft (wheel).

Back-up monitor – Video camera mounted on rear of motor home to assist the driver visually with backing up the motor home, via a monitor mounted in the driver’s compartment or in a central area of the cab where it can be viewed by the driver from the driver’s seat. These monitors are usually left in the ‘on’ position to also assist the driver with the flow of traffic behind the motor home and in watching a “towed” vehicle.

Ball Mount – The part of the hitch system that supports the hitch ball and connects it to the trailer coupler. Ball mounts are available in load-carrying and weight-distributing configurations.

Basement Model – An RV that incorporates large storage areas underneath a raised chassis.

Black Water – Waste (sewage) from the toilet that is flushed into a black water holding tank, usually located beneath the main floor of the RV.

Blueboy/Blue-Boy – Term for portable waste holding tank, often this plastic tank comes in a bright shade of blue, hence the term.

Boondocking – Camping in an RV without benefit of electricity, fresh water, and sewer utilities.

Bowtie – Reference to Chevrolet because of the “bowtie” trademark.

Box – Reference to motor home’s “living space” on a class A, built from the chassis up.

Brake Actuator – a device mounted under the dash of a towing vehicle to control the braking system of the trailer. Most brake actuators are based on a time delay, the more time the tow vehicle brakes are applied the “harder” the trailer brakes are applied.

Brake Controller – A control unit mounted inside the vehicle that allows electric trailer brakes to become activated in harmony with the braking of the tow vehicle. This device can be used to adjust trailer brake intensity, or to manually activate the trailer brakes.

Breakaway Switch – is a safety device that activates the trailer brakes in the event the trailer becomes accidentally disconnected from the hitch while traveling.

BTU – British thermal unit – A measurement of heat that is the quantity required to raise the temperature of one pound of water 1 degree F. RV air-conditioners and furnaces are BTU-rated.

Bubble – Loose term for defining a variety of conditions; such as when describing the level of RV sitting. (For example: my RV is ‘off-level’ a half bubble; referring to a ‘bubble-leveler’ tool). This can also be used to describe a delamination condition.

Bump Steer – A term used to describe a condition where the front axle feels to be rapidly bottoming out on the jounce bumpers and transferred back through the steering column and steering wheel. There can be several different causes to the problem with different cures for each condition. Sometimes a simple fix such as shocks or a steering stabilizer; sometimes more detailed corrections needed for correcting serious manufacturing oversights.

Bumper-Mount Hitch – This type of hitch is available in two configurations: A bracket with a ball mounted to the bumper or a ball is attached to the bumper (typically on pickup trucks). These hitches have very limited RV applications.

Bumper-Pull – Slang term regarding the hitch or towing method for a conventional travel trailer or popup; receiver and ball-mount type hitch.

Bunkhouse – An RV area containing bunk beds instead of regular beds.

Cabover – The part of a type C mini-motor home that overlaps the top of the vehicle’s cab, and usually contains a sleeping or storage unit.

Camber – Wheel alignment – Camber is the number of degrees each wheel is off of vertical. Looking from the front, if the tops of wheels are farther apart than bottoms, it means “positive camber”. As the load pushes the front end down, or the springs get weak, camber would go from positive to none to negative (bottoms of wheels farther apart than tops).

Camper Shell – is a removable unit to go over the bed of a pickup truck.

Campground – Any kind of park that allows overnight stays in an outdoor sleeping area. It can be accessible only by foot, by hikers or backpackers, or can be a well developed RV Resort Park.

Caravan – A group of RVers traveling together with their various RVs. Large caravans often space RVs five minutes or so apart with CB radios used for communication between the various RVers. The end vehicle is sometimes called the “tailgunner” and it’s the occupants watch out for a caravan member that may have had road trouble in order to assist, however possible.

Cassette Toilet – Toilet with a small holding tank that can be removed from outside the vehicle in order to empty it.

Castor – Wheel alignment – The steering wheels’ desire to return to center after you turn a corner.

Chassis Battery – Battery in motor home for operating 12 volt components of drive train.

Class A Motor home – An RV with the living accommodations built on or as an integral part of a self-propelled motor vehicle. Models range from 24 to 40 feet long.

Class B Motor home –is also known as a camping van conversion. These RVs are built within the dimensions of a van, but with a raised roof to provide additional headroom. Basic living accommodations inside are ideal for short vacations or weekend trips. Models usually range from 16 to 21 feet.

Class C Motor home – An RV with the living accommodations built on a cutaway van chassis. A full-size bed in the cabover section allows for ample seating, galley and bathroom facilities in the coach. It is also called a “mini-motor home” or “mini.” Lengths range from approximately 16 to 32 feet.

Coach – Another name for a motor home

Cockpit – The front of a motorized RV where the pilot (driver) and co-pilot (navigator) sit.

Condensation – Condensation is a result of warm moisture-laden air contacting the cold window glass.  Keeping a roof vent open will help to reduce the humidity levels.  Those added roof vents help to prevent cold air from dropping down through the vent while still allowing moist air to escape. Using the roof vent fan when showering or the stove vent fan when cooking also helps prevent excess moisture buildup.

Converter – An electrical device for converting 120-volt AC power into 12-volt DC power. Most RVs with electrical hookups will have a converter, since many of the lights and some other accessories run on 12-volt DC.

Covered Camper Wagons/Tepees – are canvas-covered wagons with or without electricity. Typically accommodates four or more people.

Coupler – The part of a trailer A-frame that attaches to the hitch ball.

Crosswise – A piece of furniture arranged across the RV from side to side rather than front to rear.

Curb Weight – The weight of a basic RV unit without fresh or waste water in the holding tanks but with automotive fluids such as fuel, oil, and radiator coolant.

Curbside – The side of the RV that would be at the curb when parked.

Detonation – Also known as “knock” or “ping,” this is a condition in which some of the unburned air/fuel in the combustion chamber explodes at the wrong time in the ignition cycle, increasing mechanical and thermal stress on the engine.

Diesel Puller – Term for front engine diesel motor home.

Diesel Pusher – is a motor home with a rear diesel engine.

Dinette – booth-like dining area. Table usually drops to convert unit into a bed at night.

Dinghy – A vehicle towed behind a motor home, sometimes with two wheels on a special trailer called a tow dolly, but often with all four wheels on the ground.

Dry Camping/Boondocking – camping in a recreational vehicle with no hookups and no utilities.

DSI Ignition – direct spark ignition – this term refers to the method of igniting the main burner on a propane fired appliance. The burner is lit with an electric spark and the flame is monitored by an electronic circuit board. This ignition system is used in refrigerators, furnaces and water heaters. There is now a version of stove tops that light the burners with a DSI ignition.

Dual Electrical System – RV equipped with lights, appliances which operate on 12-volt battery power when self-contained, and with a converter, on 110 AC current when in campgrounds or with an onboard generator.

Dually – A pickup truck, or light-duty tow vehicle, with four tires on one rear axle.

Ducted AC – is air conditioning supplied through a ducting system in the ceiling. This supplies cooling air at various vents located throughout the RV.

Ducted HEAT – is warm air from the furnace supplied to various locations in the RV through a ducting system located in the floor. (Similar to house heating systems)

Dump station – Usually a concrete pad with an inlet opening connected to an underground sewage system at a campground or other facility offering dumping service to RV travelers.

DW – Dry weight. The manufacturer’s listing of the approximate weight of the RV with no supplies, water, fuel or passengers.

Engine Oil Cooler – A heat exchanger, similar to a small radiator, through which engine oil passes and is cooled by airflow.

Equalizing Hitch – is a hitch that utilizes spring bars that are placed under tension to distribute a portion of the trailer’s hitch weight to the tow vehicle’s front axle and the trailer’s axles. The hitch is also known as a weight-distributing hitch.

Extended Stay Site – Sites allotted for RVers to stay for an extended period of time, like a month or a season. Often times, parks that allow extended stays have restrictions against RVs that are more than 5 or 10 years old.

Federal Parks — Parks run by the National Forest Service (NFS) or the National Park Service (NPS). These parks often offer work programs for reduced rate camping.

Fifth-Wheel Trailers – Fifth-wheel trailers are designed to be coupled to a special hitch that is mounted over the rear axle in the bed of a pickup truck. These trailers can have one, two or three axles and are the largest type of trailer built. Because of their special hitch requirements, fifth-wheel trailers can only be towed by trucks or specialized vehicles prepared for fifth-wheel trailer compatibility.

Final Drive Ratio – is the reduction ratio found in the gear set that is located farthest from the engine. This is the same as the axle ratio.

Fiver – Other name for fifth wheel.

FMCA – Abbreviation for Family Motor Coach Association.

Frame-Mount Hitch – Class II and higher hitches are designed to be bolted to the vehicle frame or cross members. This type of hitch may have a permanent ball mount, or may have a square-tube receiver into which a removable hitch bar or shank is installed.

Fresh water – Water suitable for human consumption.

Full hookup – Term for campground accommodations offering water, sewer/septic and electricity; also refers to a RV with the abilities to use ‘full-hookups’.

Full-timing – Living in one’s RV all year long. These RVers are known as full-timers.

Galley – The kitchen of an RV.

Gas Pusher – Slang for rear gasoline engine mounted chassis on motor home.

Gaucho – Sofa/dinette bench that converts into a sleeping unit; a term less used now than formerly.

GAWR (Gross Axle Weight Rating) – The manufacturer’s rating for the maximum allowable weight that an axle is designed to carry. Gawr applies to tow vehicle, trailer, and fifth-wheel and motor home axles.

GCWR (Gross Combination Weight Rating) – is the maximum allowable weight of the combination of tow vehicle and trailer/ fifth-wheel, or motor home and dinghy. It includes the weight of the vehicle, trailer/fifth-wheel (or dinghy), cargo, passengers and a full load of fluids (fresh water, propane, fuel, etc.).

Gear Vendor – Brand name for an auxiliary transmission designed to give the driver control of the vehicle’s gear ratio and being able to split gears for peak performance and at the same time have an overdrive.

Generator – An electrical device powered by gasoline or diesel fuel, and sometimes propane, for generating 120-volt AC power.

Genset – Abbreviation for generator set.

Gooseneck – A colloquial name for fifth-wheel travel trailers.

Gray water – is used water that drains from the kitchen and bathroom sinks and the shower into a holding tank, called a gray water holding tank that is located under the main floor of the RV.

Group Camping Areas — Camping areas at a campground that accommodate larger groups of twenty or more. Typically group camping areas have a fire ring and/or other central location for group activities.

GTWR (Gross Trailer Weight Rating) – Maximum allowable weight of a trailer, fully loaded with cargo and fluids.

GVWR (Gross Vehicle Weight Rating) – is the total allowable weight of a vehicle, including passengers, cargo, fluids and hitch weight.

Hard-sided – RV walls made of aluminum or other hard surface.

Heat Exchanger – A heat exchanger is a device that transfers heat from one source to another. For example, there is a heat exchanger in your furnace – the propane flame and combustion products are contained inside the heat exchanger that is sealed from the inside area. Inside air is blown over the surface of the exchanger, where it is warmed and the blown through the ducting system for room heating. The combustion gases are vented to the outside air.

Heat Strip – A heat strip is an electric heating element located in the air conditioning system with the warm air distributed by the air conditioner fan and ducting system. They are typically 1500 watt elements (about the same wattage as an electric hair dryer) and have limited function. Basically they “take the chill off”

High Profile – is a fifth-wheel trailer with a higher-than-normal front to allow more than 6 feet of standing room inside the raised area.

Historic sites — These are sites of national cultural importance. They include buildings, objects, monuments and landscapes. Historic sites are generally open to visitors.

Hitch – The fastening unit that joins a movable vehicle to the vehicle that pulls it.

Hitch Weight – The amount of weight imposed on the hitch when the trailer/fifth-wheel is coupled. Sometimes it is referred to as conventional trailer “tongue weight.” Hitch weight for a travel trailer can be 10-15 percent of overall weight; fifth-wheel hitch weight is usually 18 to 20 percent of the overall weight.

Holding Tanks – Tanks that retain waste water when the RV unit is not connected to a sewer. The gray water tank holds wastewater from the sinks and shower; the black water tank holds sewage from the toilet.

Hookups – The ability of connecting to a campground’s facilities. The major types of hookups are electrical, water and sewer. If all three of these hookups are available, it is termed full hookup. Hookups may also include telephone and cable TV in some campgrounds.

House Battery – Battery or batteries in motor home for operating the 12-volt system within the motor home, separate from the chassis.

HP – Abbreviation for “horse power”.

HR – Abbreviation for Holiday Rambler, a well-known RV manufacturer.

Hula skirt – Term used for a type of dirt skirt accessory some RVers use on the back of their motor home to aid in the protection from debris thrown from their rear wheels to the vehicles directly behind them or being towed behind them. This dirt skirt is usually the length of the rear bumper and resembles a ‘short’ version of a Hawaiian ‘hula-skirt’, hence the term.

Inverter – A unit that changes 12-volt direct current to 110-volt alternating current to allow operation of computers, TV sets, and such when an RV is not hooked up to electricity.

Island Queen – is a queen-sized bed with walking space on both sides.

Jackknife – 90% angle obtained from turning/backing fifth wheel or travel trailer with tow vehicle. Jackknifing a short bed truck towing a fifth wheel without the use of a slider hitch or extended fifth wheel pin box can result in damage to the truck cab or breaking out the back window of the truck cab from the truck and fifth wheel “colliding”.

KOA – Kampgrounds of America, a franchise chain of RV parks in North America that offers camping facilities to vacationers and overnighters.

Laminate – sandwich of structural frame members, wall paneling, insulation and exterior covering, adhesive-bonded under pressure and/or heat to form the RVs walls, floor and/or roof.

Leveling – Positioning the RV in camp so it will be level, using ramps (also called levelers) placed under the wheels, built-in scissors jacks, or power leveling jacks.

Limited-Slip Differential – A differential that is designed with a mechanism that limits the speed and torque differences between its two outputs, ensuring that torque is distributed to both drive wheels, even when one is on a slippery surface.

Livability Packages – are the items to equip a motor home for daily living, which may be rented at nominal cost from rental firm, rather than brought from home. Include bed linens, pillows and blankets, bath towels, pots and pans, kitchen utensils, cutlery.

Log Cabins — Typically two or more rooms, and accommodates four or more people. Cabins usually have private bathrooms and a kitchen area with a refrigerator.

LP Gas – Propane; abbreviation for liquefied petroleum gas, which is a gas liquefied by compression, consisting of flammable hydrocarbons and obtained as a by-product from the refining of petroleum or natural gas. Also called bottled gas, LPG (liquid petroleum gas) and CPG (compressed petroleum gas).

Marine parks — These are unique and outstanding marine areas set aside to conserve seawater plants and animals. They’re divided into zones that allow different, sustainable levels of commercial and recreational activities.

MH – Abbreviation for “motor home”.

Minnie Winnie – A brand model of Winnebago.

Motor coach – is the term for motor home on “bus-type” chassis.

NADA – Abbreviation for National Automotive Dealers Association.

Nature reserves –These are areas of special scientific interest, set up mainly to conserve their native plant and animal communities. Few have visitor facilities.

NCC (Net Carrying Capacity) – is the maximum weight of all passengers (if applicable), personal belongings, food, fresh water, supplies – derived by subtracting the UVW from the GVWR.

Nonpotable water – Water not suitable for human consumption.

OEM – Original Equipment Manufacturer.

Park Model – Type of RV that is usually designed for permanent parking but is shorter in length than a traditional mobile home. All the amenities of a mobile home but not built for recreational travel.

Part-timers – People who use their RV for longer than normal vacation time but less than one year.

Patio mat – Carpet or woven mat for use on ground outside of RV. It may be used whether or not a concrete patio pad is available where camping.

Payload Capacity – The maximum allowable weight that can be placed in or on a vehicle, including cargo, passengers, fluids and fifth-wheel or conventional hitch loads.

Pilot – a pilot is a small standby flame that is used to light the main burner of a propane fired appliance when the thermostat calls for heat. Pilots can be used in furnaces, water heaters, refrigerators, ovens and stove tops.

Pitch-in – Term for a RV campground “get-together”, usually means “pitching-in” a covered dish or casserole.

PO – Abbreviation for “pop-up” camper.

Pop-out – Term for room or area that ‘pops-out’ for additional living space in RV. This type of expanded living area was more common before the technology of slide-out rooms became popular and available.

Popup/Pop-Up – Folding camping trailer.

Porpoising – A term used to define an up and down motion with a RV.

Primitive camping – Also known as “dry camping”, boondocking. Camping without the modern convenience of full-hookup facilities of city/well water, sewer/septic and electricity. Primitive campers rely on ‘on-board’ systems for these conveniences; generator, batteries, stored water, etc.

Propane – LPG, or liquefied petroleum gas, used in RVs for heating, cooking and refrigeration. Also called bottle gas, for manner in which it is sold and stored.

Puller – slang for front engine motor home. Term most often used to refer to front mounted diesel engine motor homes.

Pull-through – A campsite that allows the driver to pull into the site to park, then pull out the other side when leaving, without ever having to back up.

Pusher – Slang for rear engine motor home. Term most often used to refer to diesel engine motor   homes.

Receiver – The portion of a hitch that permits a hitch bar or shank to be inserted. The receiver may be either 11/2-, 15/8- or 2-inch square; the smallest being termed a mini-hitch.

Reefer – Slang for “refrigerator”. Refrigerators are often found in either a “two way” or “three way” operating mode. Two way: has a gas mode and an AC mode. Three way: has a gas mode, AC mode, and 12v DC mode. The coolant used in RV refrigeration is ammonia. The two most common manufacturers of RV refrigerators are Norcold and Dometic.

Regional parks — Near large population centers, these parks offer open space and recreational and cultural opportunities for urban residents.

RIG – what many RVers call their units.

Road Wander – Term used to describe a lack of ability to maintain the motor home in a straight, forward travel without constant back and forth motion of the steering wheel.

Roof Air Conditioning – For most RVs, the air conditioning unit is mounted on the roof.  Some RVs have “bus a/c” that is contained in a basement storage area.

RV – short for Recreation Vehicle, a generic term for all pleasure vehicles which contain living accommodations. Multiple units are RVs and persons using them are RVers.

RVDA – Abbreviation for Recreational Vehicle Dealer’s Association.

RVIA – Abbreviation for Recreational Vehicle Industry Association.

RV Park – Almost always privately owned, caters to overnight or seasonal guests who have recreational vehicles.

RV Resort Park — Almost always privately owned, caters to overnight or seasonal guests who have recreational vehicles. RV Resort is often an indication of a well developed, higher end park, but since any RV Park can call itself an RV Resort; this is not always the case.

Safety Chains – A set of chains that are attached to the trailer A-frame and must be connected to the tow vehicle while towing. Safety chains are intended to keep the trailer attached to the tow vehicle in the event of hitch failure, preventing the trailer from complete separation. They should be installed using an X-pattern, so the coupler is held off the road in the event of a separation.

Screen room – Term for screen enclosure that attaches to the exterior of a RV for a “bug free” outside sitting area. Some screen rooms have a canvas type roof for rain protection as well.

Self-contained – An RV that needs no external connections to provide short-term cooking, bathing, and heating functions and could park overnight anywhere.

Shank – Also called a hitch bar or stinger, the shank is a removable portion of the hitch system that carries the ball or adjustable ball mount, and slides into the receiver.

Shore cord – The external electrical cord that connects the vehicle to a campground electrical hookup.

Shore Power – Electricity provided to the RV by an external source other than the RV battery.

Slide-in – Term for a type of camper that mounts on a truck bed, because often this type of camper “slides-in” to the truck bed.

Slide-out – Additional living space that “slides-out” either by hydraulics, electricity or manually, when the RV is setup for camping.

Slider – Slang for slider-hitch.

Slider-hitch – Refers to a sliding hitch used on short bed trucks for enabling them to tow fifth wheels, allowing them sufficient clearance to jack-knife the trailer.

Snowbird – Term for someone in a northern climate that heads “south” in winter months.

Soft-sides – Telescoping side panels on an RV that can be raised or lowered usually constructed of canvas or vinyl and mesh netting.

Spring Bar – Component parts of a weight-distributing hitch system, the spring bars are installed and tensioned in such a manner as to distribute a portion of the trailer’s hitch weight to the front axle of the tow vehicle and to the axles of the trailer.

State Park – These parks, run by state facilities, have many recreation opportunities and/or visitor centers. They are set within an extensive scenic setting.

State Wayside – Rest stops providing parking areas and restroom facilities with limited or no recreational opportunities.

State conservation areas — These are parks, often containing important natural environments, which have been set aside mainly for outdoor recreation.

Stinger – See shank.

Street side – The part of the vehicle on the street side when parked.

Sway – Fishtailing action of the trailer caused by external forces that set the trailer’s mass into a lateral (side-to-side) motion. The trailer’s wheels serve as the axis or pivot point. This is also known as “yaw.”

Sway Control – Devices designed to damp the swaying action of a trailer, either through a friction system or a “cam action” system that slows and absorbs the pivotal articulating action between tow vehicle and trailer.

Tail Swing – Motor homes built on chassis with short wheelbases and long overhangs behind the rear axle are susceptible to tail swing when turning sharply. As the motor home moves in reverse or turns a corner, the extreme rear of the coach can move horizontally and strike objects nearby (typically road signs and walls). Drivers need to be aware of the amount of tail swing in order to prevent accidents.

Tail gunner – is the end RV or vehicle in a caravan.

Telescoping – Compacting from front to back and/or top to bottom to make the living unit smaller for towing and storage.

Tent Sites – no utilities, allows tent campers only.

Thermocouple – a thermocouple is a device that monitors the pilot flame of a pilot model propane appliance. If the pilot flame is extinguished the thermocouple causes the gas valve to shut off the flow of gas to both the pilot flame and the main burner.

Three-way refrigerators – These are appliances that can operate on a 12-volt battery, propane, or 110-volt electrical power.

Tip-out – Term for room (generally in older RVs) that “tipped-out” for additional living space once RV was parked. Newer RVs mainly use ‘slide-out’ rooms.

Toad – Another name for the towed vehicle.

Toe – Wheel alignment – Toe is the measure of whether the front of the wheels (looking down from the top) are closer (toe-in) or farther (toe-out) than the back of the wheels.

Tongue Weight – The amount of weight imposed on the hitch when the trailer is coupled. See “hitch weight.”

Tow Bar – A device used for connecting a dinghy vehicle to the motor home when it’s towed with all four wheels on the ground.

Tow Rating – The manufacturer’s rating of the maximum weight limit that can safely be towed by a particular vehicle. Tow ratings are related to overall trailer weight, not trailer size, in most cases. However, some tow ratings impose limits as to frontal area of the trailer and overall length. The vehicle manufacturer according to several criteria, including engine size, transmission, axle ratio, brakes, chassis, cooling systems and other special equipment, determines tow ratings.

Tow car – A car towed by an RV to be used as transportation when the RV is parked in a campground.

Toy-hauler – Term for fifth wheel, travel trailer or motor home with built-in interior cargo space for motorcycles, bikes, etc.

Trailer Brakes – Brakes that are built into the trailer axle systems and are activated either by electric impulse or by a surge mechanism. The overwhelming majority of RVs utilize electric trailer brakes that are actuated when the tow vehicle’s brakes are operated, or when a brake controller is manually activated. Surge brakes utilize a mechanism that is positioned at the coupler that detects when the tow vehicle is slowing or stopping, and activates the trailer brakes via a hydraulic system (typically used on boats).

Transmission Cooler – A heat exchanger similar to a small radiator through which automatic transmission fluid passes and is cooled by airflow.

Travel Trailer – Also referred to as “conventional trailers,” these types of rigs have an A-frame and coupler and are attached to a ball mount on the tow vehicle. Travel trailers are available with one, two or three axles. Depending upon tow ratings, conventional trailers can be towed by trucks, cars or sport-utility vehicles.

Triple towing – Term for three vehicles attached together. This is usually a tow vehicle pulling a fifth wheel and the fifth wheel pulling a boat.

TV – Abbreviation for “tow vehicle”.

Umbilical Cord – The wiring harness that connects the tow vehicle to the trailer, supplying electricity to the trailer’s clearance and brake lights, electric brakes and a 12-volt DC power line to charge the trailer’s batteries. An umbilical cord can also be the power cable that is used to connect to campground 120-volt AC electrical hookups.

Underbelly – The RVs under floor surface, which is protected by a weatherproofed material.

UTQGL (Uniform Tire Quality Grade Labeling) – A program that is directed by the government to provide consumers with information about three characteristics of the tire: tread wear, traction and temperature. Following government prescribed test procedures, tire manufacturers perform their own evaluations for these characteristics. Each manufacturer then labels the tire, according to grade.

UVW (Unloaded Vehicle Weight) – Weight of the vehicle without manufacturer’s or dealer-installed options and before adding fuel, water or supplies.

Wagonmaster – A leader, either hired or chosen, who guides a caravan of recreational vehicles on a trip. The wagonmaster usually makes advance reservations for campgrounds, shows, cruises, sightseeing and group meals.

Wally World – Slang term used by RVers to describe a Wal-Mart.

Weekender’s – People who own their RVs for weekend and vacation use.

Weight-Carrying Hitch – Also known as a “dead-weight” hitch, this category includes any system that accepts the entire hitch weight of the trailer. In the strictest sense, even a weight-distributing hitch can act as a load-carrying hitch if the spring bars are not installed and placed under tension.

Weight-Distributing Hitch – Also known as an “equalizing” hitch, this category includes hitch systems that utilize spring bars that can be placed under tension to distribute a portion of the trailer’s hitch weight to the tow vehicle’s front axle and the trailer’s axles.

Weights: – water (weight): 8.3 lbs. per gallon; LP gas (weight): 4.5 lbs. per gallon; Gasoline: weighs 6.3 pounds per gallon; Diesel fuel: weighs 6.6 pounds per gallon; Propane: weighs 4.25 pounds per gallon.

Wet Weight – Term used by RVers to describe the weight of a RV with all storage and holding tanks full. i.e., water, propane, etc.

Wheelbase – Distance between center lines of the primary axles of a vehicle. If a motor home includes a tag axle, the distance is measured from the front axle to the center point between the drive and tag axles.

Wide body – Designs that stretch RVs from the traditional 96-inch width to 100 or 102 inches.

Wilderness – Wilderness is usually an ‘overlay’ on national parks or reserves. Wilderness areas are large, remote and essentially unchanged by modern human activity. They are managed so that native plant and animal communities are disturbed as little as possible.

Winnie – Nickname for Winnebago, a well-known RV manufacturer.

Winterize – To prepare the RV for winter use or storage.

World Heritage-listed areas – The globally recognized World Heritage list contains some of the most important examples of natural and cultural heritage in the world. More than 600 precious places are on the list, from the Great Barrier Reef to the pyramids of Egypt.

Yaw – Fishtailing action of the trailer caused by external forces that set the trailer’s mass into a lateral (side-to-side) motion. The trailer’s wheels serve as the axis or pivot point. This is also known as “sway.”

Yurts – circular, domed tent-like structures with wood floors, electricity, heating, lockable doors and sleeping accommodations for typically for four or more people.