Oftentimes I watch the tachometer on my truck more than the speedometer, and the former was spinning at about 2,100 rpms as I cruised down Bozeman Pass into the Montana town of the same name. This was last July, the sky was clear, the stars bright and the hour late.

My Labrador retriever co-pilot and I had left home near the Twin Cities very early that morning, and now, ready for sleep, I pulled off Interstate 90, a fifth-wheel RV angling neatly behind my pickup.

At another time, in another place, I might be headed for a state park or a national forest campground. But on this evening, I joined perhaps 50 other bigger or smaller, but conceptually similar, outfits in a Walmart parking lot.

So packed with RVs, in fact, was the Supercenter’s huge blacktop slab that, had I not summoned the parking wizardry that only semitrailer truck drivers and former semi drivers possess, I could not have successfully shoehorned my rig between a California-licensed Prevost motor home towing two dune buggies and what appeared to be an aging hippie camped beneath a tarp in the back of a ’72 Toyota Tacoma.

“You woke me up,” the guy said, peeking out from beneath the tarp. “Got a beer?”

“Who do you think you’re talking to?” I said. Then, “Of course, I have a beer.”

Because Walmart welcomes travelers on wheels to overnight in their lots for free, many vacation veterans, especially those caught between more aesthetically inspiring locales, are only too happy to pitch camp in the blue-white penumbra of Sam Walton’s brainchild.

On this particular night I was en route to Missoula, Mont., where my wife, Jan, would be arriving the next day, flying, as Arlo Guthrie sang in 1968, in a big airliner. Our plan was to camp for a week an hour south of that city, at a national forest campground on the shores of Lake Como, in the Bitterroot River Valley. Our two sons live in Missoula and would join us as their schedules allowed.

This would be our first major trip with the fifth-wheel, a 2018 model we bought slightly used last spring. Previously, we had owned pickup campers, which we enjoyed, especially when the boys were young. When paired with a boat or horse trailer, this type of RV was particularly useful.

When we decided to step up to a bigger RV, my wife and I had considered a travel trailer. Also called pull-behinds or bumper-pulls, these have advantages. But we already had a gooseneck horse trailer, and because we could fairly easily accommodate a fifth-wheel hitch in the bed of our 1-ton pickup, we opted for the fifth-wheel RV instead.

In considering our RV purchase, we were aware of the lightweight phenomenon that has dominated RV manufacturing in recent years. Americans’ fascination with ever-smaller pickups and SUVs powered by V6s and even turbocharged four-bangers has virtually required RV builders to utilize featherweight materials in order to similarly downsize, in weight and volume, their wheeled homes.

An aside here:

Owning an RV is a lot like owning a second home. Both have plumbing, wiring and a host of appliances, all of which, in the case of the RV, are at times subjected to road pounding for hours on end. Which is why it’s often said that if you’re going to own a camper on wheels, it’s best if you are a handyman — or are married to one.

That’s changed somewhat in recent years as RV consumers have demanded better products and manufacturing processes have improved. However, in my view, the more common use of lightweight materials in all types of RVs should be considered carefully by consumers, model to model, before purchasing.

Adventurous vacations. But cheaper?

Much is made by RV builders about the relative vacation value these rigs offer. One industry study found savings of 21% to 64% for four people traveling by RV, compared to more traditional vacations involving motels, etc.

Maybe that’s true. But if an RV owner plans to travel with his or her camper vs. park it for extended periods at given vacation sites, fuel and other costs must be considered.

Case in point: The 1-ton, diesel-powered trucks our family has owned to tote pickup campers and now pull a fifth-wheel get about 20 mpg on the highway, empty. That number falls to about 12 mpg when hauling or towing a camper. And against a headwind, it might be 10 mpg.

Doing the math, the distance from the Twin Cities to Missoula is about 1,200 miles, requiring for my jaunt last summer about 100 gallons of fuel. At about $3 a gallon, that adds up to $300 in fuel cost, one-way.

Even with a smaller, lightweight tow-behind trailer pulled by a compact or midsize pickup or SUV, it’s unlikely the achieved miles-per-gallon would exceed 18, and might be less.

The point is twofold:

Everything involving the purchase and use of a particular RV is a trade-off. And if you travel with an RV, fuel and other expenses — particularly those involving where you park at night — must be weighed.

Example:

A Minnesota state park campsite with electric hookup can run $30 a night. Water and sewer, where available, can add another $8 a night. Considering Minnesota has the best state parks in the nation, these costs represent great values, in my view. Still, overnight stays at national forest campgrounds, of which Minnesota has many, are about half the cost, though most don’t feature electricity or certain other amenities (which some campers consider part of their charm).

These are but a few of the almost countless considerations that will greet visitors this weekend to the RV, Vacation and Camping Show at the Minneapolis Convention Center.

In the end, no matter which type of RV is chosen for purchase (or rental), the open road awaits.

As do new friends with similar interests.

That aging hippie in the Walmart parking lot?

He greeted me the next morning the same way he did when we first met.

“You woke me up,” he said. “Got a beer?”