Truck Camper Adventure is pleased to present this interview with truck camper enthusiast and explorer Cal Willis. Known as “cewillis” on the truck camper forums, Cal has been exploring national parks and off-road trails since the 1970s. Cal grew up in North Kansas City, MO until college, lived in California for 35 years, and now calls Tucson, Arizona his home. He holds a Bachelor’s degree in Physics, a Master’s in Applied Mathematics, and completed graduate work in Computer Science. His work included the development of synchronous satellite control software and the design of computer network systems. Cal stays physically fit by exercising an hour a day, six days a week. He’s been married to his wife Tina for 33 years.
Thanks, Cal, for taking the time to talk. You have a pretty impressive travel resume.
Cal: I’m happy to talk, but I don’t have near the history or experience of Eric (SeldomSeen) Smith, Dave (Whazoo) Rogers, Jeff (Jefe4x4) Reynolds, or many others. Nor do I consider myself an expert off-road driver. I’ve driven many roads that are remote and/or rough and/or steep, but nothing anyone would call technically difficult.
How long have you been exploring the American West in RV’s?
Cal: If the back of a Suburban counts, then the early 1970’s. A few trips from our home then in Los Altos Hills, CA to the southwest desert: Organ Pipe National Monument and Death Valley National park. Then in the 1980’s to the Lake County area when we were thinking of moving in that direction. First real RV was a rented truck camper about 1974 for a camping and fishing trip to the Klamath River in Oregon.
When did you buy your first RV and what was it?
Cal: In 2005, after I had long since retired, I decided it was time to see Alaska. I had a 1997 GMC 1500 4×4 at the time, so I looked for the lightest camper that I thought I could live in for several weeks, and found a used Four Wheel Grandby camper. It was amazing how much dirt and sand had been ground into the seat and bed covers of that camper when I bought it. The camper got a thorough cleaning, a furnace, new foam for the seats and bed, and two 6 volt batteries from my golf cart. To the truck I added a set of used (but good) load range E tires, an extra spare tire, a junkyard tailgate, and a heavy-duty camper battery charge circuit. The camper hung over the end of my short-bed by 18 inches, but the balance was acceptable. The truck had a 1.5 inch rear spring sag and no side-to-side sway. I was well within my truck’s spring, axle, wheel, and tire ratings.
What parts of Alaska did you explore in your Grandby?
Cal: In six weeks, I saw a lot of Alaska, from Kodiak Island to Deadhorse, on the Arctic Ocean. Plus I got a quick look at some of western Canada. The truck turned 100,000 miles on the trip.
Do you still own the Grandby?
Cal: No, I now own a 2007 Outfitter Apex 8. I bought it new. It came with a standard east-west bed, oven, 110 watt solar power system, a Tundra 12 volt compressor refrigerator, a cassette toilet, four 12 volt 135 amp hour AGM batteries, a rear awning, and no dining table for more floor space. I use a folding table.
Why did you choose the Outfitter Apex 8?
Cal: I knew I wanted a pop up in order to get it through a 7-foot garage door for inside storage (dismounted of course), a little more overhead clearance, and somewhat lower center of gravity (CG). Also, I wanted a little more luxury (i.e. a real bathroom with inside shower) than my original Grandby. Obviously, I was not intending to “rough it,” even far from civilization. I talked extensively with Steve Urban and the late Don Curly about camper features. I considered an Outfitter Apex 8, a Hallmark Ute, a Northstar 850 SC, a Four Wheel Camper, and an Alaskan–all high-quality products. After eliminating the last two campers for various reasons, I made a detailed cost/benefit/feature spreadsheet on the first three. For the features I wanted, and the cost, the Outfitter looked the best. I then visited the Hallmark and Outfitter factories, looked the products over, talked to the owners, and made my decision.




Wow, you really did your homework! What were the biggest reasons for choosing an Outfitter Apex 8 over the other camper makes and models?
Cal: In addition to having the options I wanted, my decision was strongly influenced by the size of the Apex’s fresh water tank (44 gallons), the fact that the holding tanks are heated, and the amount of interior headroom.
Which tie-down system do you use for your Apex?
Cal: Torklift
Have you made any modifications to your Apex?
Cal: I’ve made very few changes, since I bought it how I wanted it. I did add a second 12 volt plug outlet, added an adjustable thermostat to the water heater, and upgraded the water pump to a variable speed model. I’ve also made a number of repairs because of rough roads and operator error. These include re-installing my rear awning after vibration sheared the screws on the Hole-in-the Rock Road, relocating my solar panel after a screw sheared somewhere, and replacing the plastic roof corner guards with aluminum ones after damaging the plastic after hitting my workshop wall.
What pickup truck do you presently drive and why did you choose that make and model?
Cal: My current truck is a 2006 GMC 2500HD 4×4 6.5 foot bed with an LBZ Duramax engine and the Allison 6-speed auto transmission. I evaluated Duramax and Allison as the best diesel and transmission combination available in 2006. I was also impressed by the G-80 Eaton auto locking rear differential. And I had good luck with two previous GMC trucks. By the way, I would have gladly bought the same configuration 3500 SRW–but GM didn’t make one!
What off-road modifications have you made to your truck?
Cal: It’s kind of hard to separate modifications into “for off-road” or not, since the truck needs to carry the camper, and I bought the camper for off-road travel and camping. As I mentioned, since I couldn’t get a 3500 SRW, the first thing I did was upgraded the wheels, tires, and leaf springs. Wheels were from a 3500 SRW truck, and I increased the tire size from 245/75R16 to 265/75R16. For the springs, I bought a set of top overload packs actually made for earlier model GM trucks, because the set included adjustable brackets (the only ones I could find). The capacity is 1,200 pounds per side. With this setup, I could adjust the brackets for no contact unloaded, and zero rear end sag fully loaded, with no adverse handling problems. The only problem with this setup was that I quickly wore out the spring pads. I went through at least three iterations of pads trying to find something that would fit my brackets, work right, and last. Terry Rey suggested that I try Ultra High Molecular Weight Polyethylene. The stuff wears better than spring steel, but cuts and drills as easily as wood and is cheap. Thousands of miles and no more problems.
What are the GVWR and payload ratings of your GMC?
Cal: The GVWR is 9,200 pounds. There is no payload rating sticker. The original certified scale weight with full fuel and me, but no tail gate was 6,720 pounds (now about 6,900 – 7,000 pounds with bigger wheels, tires, springs, and step bars.). The last fully loaded weight I got with the camper was 9,350 pounds. Since my AAM rear axle has a capacity of over 10,000 pounds, and my spring capacity is increased by more than 2,400 pounds from stock, I’m happy staying under a rear axle weight determined by my tires of 6,840 pounds. The actual loaded rear axle weight is 5,300 pounds.
Have you made any other modifications to your truck?
Cal: Yes, I upgraded the truck camper’s battery charge circuit by using 2 gauge wire, a 150 amp continuous duty solenoid, and fuses at both ends. With a fuse bypass, this circuit can also supply power to my winch when mounted at the back of the truck. In addition, with a little help from a differential shop, I installed an Eaton electric locker in the front differential. Other additions to the truck include front receivers in place of tow hooks and an extended skid plate to protect the undercarriage.




Which type of engine do you prefer, diesel or gas?
Cal: I have an engineering preference for the theoretical simplicity and efficiency of a diesel. I realize that modern diesels are NOT simple and efficiency is a relative term. I also really like the torque and better mileage for equivalent power.
What tires do you have on your truck now and what inflation values do you typically run when exploring off-road?
Cal: I run Cooper Discoverer AT3 265/75R16E tires. Always at the maximum inflation of 80 PSI, unless additional traction is needed (which has not happened to me, so far). Normally, if I can’t get there with all four wheels locked, I don’t need to go. I prefer to retain full tire load capacity and sidewall stiffness.
What tools and recovery gear do you consider essential when exploring off-road?
Cal: Some kind of personal locator device and enough fuel to get back. Of the gear that I take, those are the only ones I’ve used so far. Here’s what I bring: a SPOT satellite personal tracker–sends OK, Help, or Emergency messages (only used OK so far), an extra 10 gallons of diesel, two mounted spares, a winch with synthetic cable, extra winch cable, a heavy-duty snatch block, a D-ring, a tree strap, and other straps. I also carry a plow-type sand anchor, a reasonable amount of tools, tire repair plugs, bottle jack, air compressor, and tire chains.
Of all the trails that you’ve been on, do you have any favorites?
Cal: Not really. They’re all good so far. But it’s hard to beat the scenery on the Grand Canyon North Rim.
I agree. Which trail has been the most challenging to you?
Cal: I’ll answer that two ways. Those that I didn’t complete for one reason or another and those where I encountered actual trouble. Kelly Point Road on the Grand Canyon’s North Rim was one trail I wasn’t able to complete. It had too many large rocks for the available time and was more than 100 miles from help. Collet Canyon Road off the Hole-in-the Rock Road in southern Utah had a really bad spot that would have taken a lot of hand work to get past. Some side trail off the Nacimiento-Fergusson Road, west of Fort Hunter Liggett, CA, gave me some difficulty, too. The road had deep powder dirt on a steep section. I was unable to get any traction even with both differentials locked.
I’ve only had real trouble once–that was on a winter trip with Dave Rogers to Goblin Valley State Park, UT and vicinity. Dave had gone ahead up Temple Mountain Road to find a camp site, and I followed later. Both rear wheels suddenly spun and I went right into the ditch. I didn’t have my front locker or my winch at the time. I did have chains, but they weren’t on. It was my fault. With better awareness, I could have avoided the situation. However, this is the one situation I can think of where the auto-locking rear axle actually hurt rather than helped. When one wheel spun, so did the other, and the rear end slid. Had I been thinking better, I might have been able to get out by putting chains on the right side wheels and using the brakes to prevent the left front wheel from spinning. I called Dave on a two-way radio, and he came back down. I decided to stay with the camper for the night, and he went back to Goblin Valley to see about a tow truck.
How did that night go in the camper?
Cal: I started to sleep in the camper–quite uncomfortable. About midnight, it had started to snow heavily, and Dave and a park ranger came back and picked me up. Most of the snow in the picture fell that night. The next day, a tow truck pulled me out with very minimal damage.




What are your favorite states where you like to explore?
Cal: Arizona and southern Utah
Those are my favorites, too. Are there any areas that you think are overlooked by most overlanders?
Cal: You don’t really expect me to answer that, do you? I like deserted roads and areas. I will say that I spent 10 days in the Grand Canyon Parashant, 50 to 100 miles from pavement, and only saw two other vehicles.
What advice would you offer to those who are considering buying a truck camper to take off-road?
Cal: As you know, it has been done successfully many ways, from the smallest popup to modest hard-sides. My best advice would be to understand the real intended use of the camper: how many people, doing what, how long, really off-road or just off-pavement. A few owners with real experience could probably offer invaluable advice. This isn’t saying much, but it’s all I’ve got.
That’s great advice, actually. If you were to buy a brand new truck camper or an overland expedition rig, and money wasn’t an issue, what make and model would it be?
Cal: I haven’t seen anything that would work any better for me, but I do like Outfitter’s newer all-composite roof, better compressor refrigerator, and a two-stage furnace (or vented cat).
What’s the most worrisome or scariest moment you’ve experienced during your adventures?
Cal: That would be Temple Mountain Road. Worrisome, but not scary.
Have you had any notable run-ins with wildlife like bears?
Cal: Not really. The closest I’ve been to a bear (that I know about) was on the Dempster Highway, Northwest Territory. I camped at an “emergency airstrip,” which was just a big open area near a long straight section of the Dempster. I saw the bear a few hundred yards away and kept watch. When it got close (about 40 yards), it just ambled down the highway and didn’t show any interest in me whatsoever. That bear looked kind of sickly to me, way too thin for September. I did have the safety off while watching closely, however.
What foods do you like to eat when you’re out exploring in your camper?
Cal: I like to use my Hibachi grill two or three times when I’m out. An occasional pizza in the oven. Also quite a bit of beans and rice and mac and cheese.
Do you have any other hobbies as they relate to the great outdoors?
Cal: Not anymore, unless you count adding on to my house. That’s partly outdoors.
Yes, it is. This has been great talking to you, Cal. Thanks again for taking the time to talk.
Cal: Thanks. It was my pleasure.
Excellent interview with Cal Willis and his off road adventures, would like to hear more about how his compressor refrigerator performed.
Hi Alex,
I have no complaints about my Tundra refrigerator. It’s been able to keep things frozen even on the WRT in June when the temperature 100+ for several straight days. The only change I made was a thin piece of insulation between the freezer and refrigerator sections — without that, with the freezer at zero, some things would freeze in the refrigerator. Also even when running a lot on the WRT, my batteries were never even close to being run down (per 540 AH battery bank and strong engine charge circuit). I’m told that newer compressor refrigerators have more space, better insulation, and higher efficiency. I wouldn’t have any other kind.
Yoe, Cal! An excellent piece on what you (we) do with our XTC’s. I like your methodical, measured paradigm on choosing a rig. Most of us just stumble onto the rig we wind up with and try to upgrade it after the fact. You went for the good stuff the first time and upgraded a few things along the way. I hear you about a locked or traction-aided rear axle pulling you down slope in slippery conditions. This tendency is worse with wide tires on said axle.
Mello: Very nice format. Here’s hoping you have a continuing rip-roaring success with your blog/on-line magazine.
jefe
Thanks, Jefe. I appreciate that. And thank you for your support.
I really enjoyed the interview. Cal was an interesting subject. Mike, Good job on the content of the questions. I thought they added a lot of interest to the interview. A good model for future postings.
Thanks, I appreciate your kind words. This is just the tip of the iceberg. Lots more to come.
Great interview, we started TCing as sons of the beach(Assateague Island.MD). Our beach rigs are a bit to cumbersome to be nimble enough for the desert jaunts you all take us on! We’ve visited Arches NP but stayed close to the paved surfaces, thanks for showing us the views beyond.
If you are inclined to come eastward we would be honored to give you a sandy tour.
Thanks, Skip. I might just take you up on that offer.
Thanks for an absolutely excellent article.
I meant to ask, how is the Outfitter Apex in cold weather as far as keeping warm inside?
Hi Harvsh,
I really don’t know how an Apex would compare to a well made hardside in terms of heat loss. There is/was a ‘cold weather pack’ available (I don’t have it) to increase the insulation value of the softsides, but there still isn’t a lot of material between the inside and outside –.
My furnace works great at keeping the inside warm, when I’m willing to run it — but it is damn noisy. So at night, I keep it on the lowest setting (about 45-50) just so there’s no chance of freezing the tanks, and grab some extra blankets.
As stated, I would like to have a 2-stage furnace (hoping that running on stage 1 would be a lot quieter) or a vented cat heater.
Thanks, Harvsh. It was really fun to do it. This is just the tip of the iceberg. Lots more to come.