Adventure in Style: Winnebago BOLDT Q70 KL

Winnebago BOLDT Q70 KL class B motorhome with large victorian home in the background
The front of the redesigned MB Sprinter is sleeker than the last iteration, and adds updated headlight buckets, grille and front bumper cover.

Winnebago BOLDT debuts with a sophisticated lithium-based house battery system, luxury appointments and off-road capabilities

Alexander von Humboldt was a 19th-century German naturalist, explorer and geographer, and was the first to extensively travel the North, Central and South American continents and record their biogeography in numerous published works. Winnebago used Humboldt as the inspiration for a Class B motorhome designed for adventure, one that could take a naturalist anywhere in comfort, but this time allowing greater comfort while advancing his/her field of study. Or just for having a great time.

When we tested the Winnebago Revel (November 2018), also built on the Mercedes-Benz Sprinter platform, we were impressed by its durability and off-road capability, and for what it was designed to do, it served well. The issue, though, is the lack of the usual amenities; there’s not even a microwave. However, members of the Revel Owner’s Group have displayed ingenuity in crafting flexible storage and even cooking space in the rear.

The Winnebago BOLDT Q70 KL is the Revel for the rest of us. Built on the longer 170-inch wheelbase Sprinter 3500 dual real-wheel platform, which was redesigned for 2019, this motorhome is able to handle a lot more weight and gives owners more luxurious interior space within and, wait for it, it’s now available in a 4X4 version, making the BOLDT an adventure-ready luxury (albeit compact) motorhome.Winnebago BOLDT Q70 KL Class B motorhome floorplan

The Inside Scoop

Stepping into the BOLDT 70KL’s side door reveals an inviting interior with glossy, Euro-style, wood-toned cabinetry and washed-oak style vinyl flooring. The white solid-surface counter­tops, padded walls and tan padded ceiling add to the feeling of airiness in this unit.
The rear cushions that make up part of the anomalous “Flex Bed” have tan-and-white tweed upholstery and are quite comfortable. That said, the design of these sleeping/sitting areas makes little sense to us, although they are workable. Each side serves as its own twin bed, which is fine. The driver’s side bed is only 6 feet long, and taller folks will touch at both ends. The passenger’s side bed is much longer, so I took the long one and my wife took the shorter. The shorter driver’s side, and rearmost, couch has two lap belts for passengers. We found these inconvenient for a couple of reasons. First, passengers are seated toward the rear of the unit, which is fine for kids, but adults who want to chat will have to speak up. Second, going down the road for long periods riding sideways isn’t the most comfortable, and a frontal collision could be problematic for those seated here. They are better designed for small kids, and the Flex Bed system has to be engaged for sleeping.

The Flex Bed system is a slatted, interlocking platform that slides out between the two twin beds. By properly inserting the cushions, an offset “queen” bed can be set up; sleeping bags or a Travasak only need apply, as no sheets will fit here. We think this is fine for the occasional adventure campout with the kids, but reality suggests that this is primarily a two-person motorhome.

Winnebago BOLDT Q70 KL Class B motorhome interior, galley area
The living area in the BOLDT is bright, cozy and highly functional; the galley has nice prep space.
Photos: Michael Gordon

The BOLDT’s Pure3 Advanced Energy System uses a Volta 11,600-watt-hour energy pack and a 3,600-watt Dimensions pure sine wave inverter with a 58-volt DC, 45-amp charger segment, paired with an added 58-volt DC alternator. There is no gas generator on board since the lithium power pack can charge relatively quickly at 58 volts DC; the chassis engine, shorepower and solar system can all contribute to charging the system. The Coleman-Mach 13,500-Btu rooftop air conditioner will run several hours on just the energy pack alone. In fact, on a four-hour photo shoot with the doors frequently open on an 85-degree day, we only depleted the energy pack to 60%, with the solar and engine alternator (at idle) contributing. While driving to the Connecticut shore, the air conditioner ran all day without issue.

While this system provides an abundance of power, running the air conditioner does tax its capabilities, and if it’s needed over a longer term, shorepower will be required. Mercedes-Benz requirements preclude the use of auto start and idle-up systems, according to Winnebago. At idle, the alternator and solar panels can’t charge enough to overcome the energy usage of the air conditioner at full tilt along with the refrigerator running, not to mention that idling a diesel engine for long periods causes an oil washdown issue, which can limit engine longevity. Mercedes-Benz offered a factory idle-up feature on older models; however, the redesign doesn’t include a high-idle function. There is an aftermarket option for 2018 and older Sprinters, so it’s possible that a company will eventually make something for aftermarket installation.

Winnebago BOLDT Q70 KL Class B motorhome bed
The Flex Bed, when assembled, is a bit of an anomaly; no sheets need apply.

The galley is nicely equipped with a 12-volt-DC Danfoss compressor-driven 4.3-cubic-foot Nova Cool refrigerator and High Pointe convection microwave. The solid-surface countertop with single-bowl stainless sink and residential Euro-styled faucet works well for food prep, and there is a nice amount of counterspace if the sink cover is in place. A single-burner induction cooktop is clean and efficient. Ventilation for the galley is provided by a roof-mounted MaxxFan.

There are two tables in the BOLDT. The first is a fold-up table/desk for use with the rotated driver’s seat, and when correctly adjusted, there’s just enough room to sit and work. Connections for power and charging are above this deployed table, and heavy-duty coat hooks are on the overhead cabinet, which came in handy for hanging rain gear out of the way while driving.

The second table is on a movable, swing-away mount for the similarly rotated passenger’s front seat, and features a cup-holder. This table can be folded flat against the back of the passenger seat when unneeded or swung out to use outside the door. Additionally, the mount is compatible with RAM Tough-Track-brand mounts throughout the motorhome, including one next to the galley, allowing it to be used by those people on the couches. Both tables offer compact, yet usable, surfaces for dining and other tasks.

The wet bath is surprisingly roomy for a Class B, and is very nicely appointed with a Thetford ceramic foot-pedal-flush toilet and solid-surface counter with stainless sink. There is ample storage and closet space here. A Moen single-handle shower diverter works well and is mated to an Oxygenics shower head. A teak-style wood-slat platform, which is removable, sits on the shower floor, allowing wet items to air dry, while any water is collected by the shower drain. A 12-volt DC push-up style exhaust fan exchanges the moisture efficiently.

Winnebago BOLDT Q70 KL Class B motorhome interior, cockpit area
The new MB Sprinter cab layout is much improved, and has the feel of a luxury vehicle.

Behind the Wheel

What’s Hot

Overall appearance, large bathroom, good closet and storage space, dovetailed drawers for strength, Volta power system, Mercedes-Benz new technology, overall handling, use of space for storage, ROCCC

What’s Not

Acceleration lag, missing features/price point; rear bed system; non-insulated heated tanks; lack of auto start, temperature sense and high-idle capability to support Volta power system
Winnebago BOLDT Q70 KL class B motorhome exterior

The new Mercedes-Benz Sprinter, with its upgraded electronics and interior, is much improved over previous models, and finally makes the Mercedes motorhome feel like, well, a Mercedes. The entire dash received a makeover, resembling little of its predecessor.
Sitting in the 14-way power driver’s seat (no typo there), behind a new multi-control smart steering wheel emblazoned with a large chrome tristar, the steering column, control stalks, and electronic dashboard support advanced technology and comfort. Gone is the transmission shift lever, replaced by a transmission control stalk, which takes some getting used to, but works well. Entertainment and computer controls are located on the face of the smart wheel, utilizing buttons, wheels and Blackberry phone-style touch buttons. The Mercedes-Benz entertainment system has a touch-screen and is voice-controllable, featuring navigation, Apple CarPlay, Wi-Fi hotspot and USB-C compatibility. The USB-C ports are located in the dash-top closable cubby, which is designed to segregate the iPhone from the driver, as there is no way to run the cord outside the closed cubby without just pinching it in the door, which is what we ended up doing. We mated an Apple USB-C adaptor with our long Lightning cable and put the phone on the console so it would be reachable if needed by the passenger. A small cubby door modification will fix this issue.
The instrumentation has a mix of analog, digital and LED gauges, which we liked, although the LED gauges for temperature and fuel are a bit difficult to see in certain conditions. A large center LED computer display works well and has too many functions to recite here.

The aforementioned 14-way adjustable front seats, which are mandated by Mercedes-Benz because of integrated air bags, are firm, but comfortable. Steering is tight and responsive and the motorhome handles well in crosswinds. A severe lag in acceleration from the start line is noticeable, up to 3 seconds. This caught us by surprise trying to make a left turn on a busy road. Once the motorhome is moving, acceleration is acceptable for ramps and passing other vehicles on the highway. Again, this is a motorhome, so a little patience will pay off economically.

Lastly, the BOLDT is available in 4WD for more adventurous souls looking to travel off pavement or to snow country.

The Outside Story

The exterior of the BOLDT is similar to the Revel in many ways. The roof rack with movable ladder mounted on the rear door stands out visually, and like the Revel, features two large solar panels, with a small amount of space for mounting or storing items. In a bit of genius, Winnebago designed a rear roof pod that includes roof clearance lights, the TV antenna and back-up camera. This keeps it aft of the rack, allowing storage flexibility. A Carefree of Colorado 15-foot power lateral arm awning sits atop the passenger’s side roof, and provides a nice covered patio space and AC-, DC- and cable-TV connections are readily accessible.

Winnebago BOLDT Q70 KL class B motorhome bathroom
With the rear doors open, the view of the relatively spacious bath is evident, with zip-down screens.

Enjoying the outside with the electric sliding side and rear doors open is possible thanks to Rolef screen systems at both doors. Once zipped up, the bug seal is tight. A great feature of the side door unit is that it’s unnecessary to unzip the door to enter and exit, thanks to a magnetic release for the van-side part of the screen zipper. Just pull it back, enter and flip it back to close, magnetically.

Utilities on the driver’s side are standard. The dump valves for the heated holding tanks are here; we had a few issues with these during the evaluation process, but they were fixed by a dealer. While the holding tanks have small heating pads, they are exposed and uninsulated, so exposure to freezing temperatures will still need to be avoided. A short sewer hose storage tube is mounted in about the only place it can be — underneath the rig. Access requires lying on the ground, but the storage space is still appreciated. A Thetford macerator system with extendable hose and handle would be a welcome feature, especially at this price point.

The Final Word

The 2020 BOLDT 70KL fit in nicely among the beautiful homes and environs of the Connecticut shoreline, and its power system is impressive, and is a sign of things to come, even without auto start and high idle features.

While we like the BOLDT for its features, its almost $206,000 price as tested seems excessive for a Class B, and while the Volta power system comes at a premium, the remainder of the motorhome doesn’t quite rise to that level. There are luxury and off-road Class B’s with far more features, like Lithionics and Xantrex power systems, macerators, multiplex wiring and ducted air conditioning on Sprinter and other platforms, that can be had for $40,000-$50,000 less.

The Volta power system in the Winnebago BOLDT Q70 KL class B motorhome
The Volta power system lives under the passenger-side bed.

That said, the new BOLDT will no doubt have future positive adjustments to its feature set, and other conveniences can easily be sourced through the aftermarket. If you’re looking for a Class B touring motorhome or an adventure rig with more amenities than the Revel, and relish 4WD versatility, then the BOLDT is a suitable contender in this space.

Winnebago Industries Inc. | 641-585-3535


The Volta power system control inside the Winnebago BOLDT Q70 KL class B motorhome
The Volta power system control is easy to access from the side door.

Model Mercedes-Benz Sprinter 3500
Engine 3.0-liter V-6 turbodiesel
SAE Hp 188 @ 3,800 rpm
Torque 325 lb-ft @ 1,400-2,400 rpm
Transmission Automatic 7-speed
Axle Ratio 3.923:1
Tires LT215/85R16 E
Wheelbase 170″
Brakes Front/Rear Disc
Suspension Front/Rear Strut/leaf spring
Fuel Capacity 24.5 gal
Fuel Economy 13.8 mpg
Warranty 3 years/36,000 miles basic;
5 years/100,000 miles powertrain

Exterior Length 23′ 4″
Exterior Width 7′ 2″
Exterior Height with A/C 9′ 11″
Interior Width 5′ 8″
Interior Height 6′ 2″
Construction Van body
Freshwater Capacity 21 gal
Black-water Capacity 16 gal
Gray-water Capacity 25 gal
Water-heater Capacity 2.6 gal
Propane Capacity 16 gal
Air Conditioner (1) 13,500 Btu
Furnace Truma Combi forced-air
Refrigerator 4.3-cu-ft ,12-volt DC
Inverter/Charger 3,600 watt/45-amp @ 58 volts DC
Batteries 11,600-watt hour, 58-volt DC lithium
AC Generator N/A
MSRP $198,614
MSRP as Tested $205,190
Warranty 12 months/15,000 miles basic; 36 months/36,000 miles structural

Wet Weight
(Water and water heater, fuel, propane tanks full; no supplies or passengers)
Total 8,809 lbs

Chassis Ratings
GAWR, F/R 4,410 lbs/7,720 lbs
GVWR/GCWR 11,030 lbs/15,250 lbs
ROCCC 2,221 lbs
GAWR Gross Axle Weight Rating
GVWR Gross Vehicle Weight Rating
GCWR Gross Combination Weight Rating
ROCCC Realistic Occupant and Cargo Carrying Capacity (full water, no passengers)



  1. why on earth would they engineer in a THREE SECOND accel lag? Could it have been a transmission software glitch? or??


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