Trucks make up a large number of the vehicles on the road today-- and for many good reasons. The commercial user expects a truck to run for 150,000 to 200 ,000 miles, or even more, and the use can be hard.
In addition to being more durable than a car, the open flat bed of a truck is a versatile cargo carrier. A truck can cart any odd-size load: firewood, trail bikes, cheerleaders, or a piece of furniture picked up at a garage sale.
Top the vehicle with a living enclosure and you have a recreation vehicle (RV) ready to take you almost anywhere, especially if you have a 4-wheel-drive. A slide-in camper loaded onto the cargo bed of a pickup truck is designed to provide living quarters similar to a van camper or a small trailer.
The truck cab is usually not directly accessible to the living quarters, but most states permit passengers to ride in the camper section while the vehicle is in motion. Many owners equip their RV with an intercom system for communication between the cab and the camper; or have a pass-through window.
Flexibility is the name of the game. When you don't need the minihome you can simply slide it off and store it. Then when you require an RV, you drive the truck under the camper and bolt it to the bed.
The campers are held in place on the truck by tie-downs, and supported on jacks when detached from the truck. The jacks operate either electrically or by hand cranks.
In other words, the slide-in camper does not become a permanent part of the truck and can be removed, thus leaving the truck free for local use. The trimmed-down truck once again provides better mileage and a usable cargo-carrying space.
Campers that extend over the cab of the truck provide additional sleeping space, but some of today's energy-conscious RV manufacturers are turning out telescoping units that drop down to cab level for more efficient highway travel.
The prospective owner of a truck camper should assure himself that his pickup truck provides the needed support for the unit that he plans to buy. Specially equipped pickup trucks are needed for the more luxurious and heavier truck campers.
Coachman of Middlebury, Ind., the nation's largest full-line manufacturer of RVs and related products, makes a new lightweight Caper XL truck camper. Designed for trucks rated at one-half ton or more, the camper has a three-burner range with hood light, icebox or two-way refrigerator, and one-inch polystyrene insulation in the sidewalls, roof, and floor.
A 12,000-B.t.u. furnace with wall thermostat, roof air conditioner, and marine toilet also are available as options.
Truck-van slide-in campers are designed for full and mini-size pickup trucks. These camper shells have an overall length of from six to 12 feet. Costs run from $1,000 (cost of truck additional), depending on the size and model.
The ''movable motels'' sleep up to four adults. Mileage is usually from two to four mpg less than when the truck is empty.
Truck-camper shipments from factories to dealers last year totaled 5,100, up 2 percent over the 5,000 shipped the year before. Overall, the RV industry was up 32 percent in 1981.
Twenty percent of the 5.8 million RVs now on the road are truck campers. That makes them second in popularity behind travel trailers, which are 35 percent of the total market.
Interestingly, truck campers make great ''starter'' vehicles for those persons just getting into the RV life style. Of all the current RV owners in the US, 29 percent had a truck camper as their first vehicle.
Dr. Richard T. Curtin, director of surveys of consumer attitude at the Survey Research Center, University of Michigan, has completed a study on RV consumers.
The survey shows that there are more travel trailers in the US today than all types of motorized RVs combined. More than 2 million of the nearly 6 million RVs on the road are travel trailers.
While these numbers are impressive, they only begin to tell the story of the total demand for towable RVs.
Combined, the three basic types of towables --travel trailers, truck campers (considered in the towable catalog), and folding campers--account for almost 70 percent of the total RV market.
To put into proper perspective, 7 out of every 10 RVs on the road--more than 4 million vehicles in all--are of the nonmotorized, towable variety.
Who are the owners of truck campers? The study found that the majority of truck-camper owners are under the age of 44 and have children at home.
Surprisingly, folding camper trailers, which normally carry the lowest price tag of all types of RVs, appeal more to high-income families and less to low-income families than either travel trailers or truck campers. A total of 39 percent of all folding-camper-trailer families have annual incomes above $25,000 , 44 percent between $15,000 and $25,000, and only 17 percent under $15,000.
By contrast, 32 percent of all travel-trailer owners and 37 percent of all truck-camper owners are in the low-income bracket while 28 percent of the travel-trailer families and 23 percent of the truck-camper people are in the high-income group.
An interesting sidebar to the study finds that the West dominates the truck-camper market with 43 percent of total use.
Pickup trucks, of course, are extremely popular in the West, so it makes sense that many of those pickup owners would opt for a truck camper when they venture into the RV market.
Reprints of the study, ''The RV Consumer: Current Trends and Future Prospects ,'' are available from the Recreational Vehicle Industry Association (RVIA), PO Box 204, 14560 Lee Road, Chantilly, Va. 22021.
The RVIA also puts out a booklet that describes the RV way of life and discusses all the RV categories. The cost is $1.