Seneca 37HJ


Photo Credit: Shawn Spence Photography

The Seneca has a truck pedigree but enough smooth lines for a modern look.

By Kevin Livingston
December 17, 2015
Filed under Motorhome Reviews, Top Stories


Jayco’s Super C, built on a Freightliner M2 cab and chassis, is earmarked for diesel-power fans who want something different without sacrificing luxury


While motorhome ownership has its perks and pleasures, finding the right fit for your lifestyle among the long list of Class A, B and C body styles can be an overwhelming task. Throw in a hybrid of sorts, the Super C, and the choices become even more complex. A Super C has the profile of a traditional cab-and-chassis-based motorhome, but is much bigger and it’s connected to underpinnings that rival diesel pushers in performance, drivability and brute strength. Jayco has long been involved in this segment of the market with its Seneca brand and the 2016 version has been refined to give hardcore diesel fans a lot of food for thought when shopping for a new motorhome. The Seneca 37HJ is rock solid and at a price tag around $235,000, this motorhome is easily in the luxury zone.

TV and fireplace are easily visible from most of the wraparound dinette and couch ensemble on the opposing wall, inside the living room slideout.

TV and fireplace are easily visible from most of the wraparound dinette and couch ensemble on the opposing wall, inside the living room slideout.

Some people might have a difficult time wrapping their head around the fact that the Seneca commands such a hefty price tag because of its similarity in appearance to a Class C, which represents a more economical category of motorhomes, but to steal a few words from a popular phrase, “This is not your father’s mini motorhome.”

What you get here is an elegantly designed interior loaded with higher-end, brand-name equipment and a cabin resting atop the reliable Freightliner M2 chassis that’s propelled by a capable Cummins ISB 6.7-liter 340-horsepower diesel/Allison 2500MH automatic transmission package. No neck-snapping power here, just an ultradurable combo that works quite well, maintaining seamless shifts as well as a distinctly sweet exhaust note that reminds you it’s a real truck.

The sure-footed Freightliner chassis will cut a 55-degree turning radius and it’s fitted with the JRide Premium suspension system that helps neutralize roadway bumps and irregularities. The JRide system is comprised of top-tier components like 60 mm Bilstein shocks, full air brakes, front sway bar and a heavy-duty rear air suspension. Bumps and vibrations not handled by the suspension are controlled by the air-ride cockpit seats. Although the macho-truck look provoked initial thoughts that the ride was going to be less than stellar, even with the advanced suspension, a few minutes down the highway and then on to uneven curved backcountry roads confirmed that it was ultimately a winning combination, supplying a smooth ride during road transitions and exhibiting very limited body roll.

Jayco-Seneca-HotNotOnce we got the air-suspended driver’s seat adjusted properly, which at first tended to feel a little squishy and bouncy, we enjoyed the ride. However, a long-legged co-pilot may find it difficult to truly stretch out for the long haul due to a large dashboard and other cabin area restrictions. When it came to pulling back on the ponies, the air brakes seem to be matched perfectly for the chassis and weight of the motorhome. Braking duties are supported by the standard engine exhaust brake.

To some, the exterior profile may seem a little rough around the edges, portraying a more bold, semi-industrious look, but the surprisingly smooth lines of the cab made for handsome contours, bolstered by the premium-grade full-body paint and shiny Alcoa aluminum wheels. Once inside, the experience gets even better.

The floorplan is not unusual and the elements work nicely in a Class C configuration with a front cabover bed/storage area. The front living room is the focal point featuring a dinette ensemble that continues forward to make the couch, all in the driver’s side slideout. Across from this area is an entertainment center with a fireplace and 39-inch LED TV. A straight-line kitchen counter is augmented by a pullout sectional and the four-door refrigerator is tucked in between the galley and center bath suite. From here, the rear is consumed by the bedroom that’s enlarged by opposing slides. Carried throughout the interior is an abundant use of storage areas, not just wildly spread out, but placed in all the right spots to convey simplicity and make workable use of otherwise dead space.

Jayco-Seneca-FloorplanAdding to the liberal use of Honey Cherry solid-hardwood cabinetry is a trick pullout pantry hiding between the toilet room and living room on the driver’s side that’s easily capable of holding foodstuffs of all sizes and even large enough for tall cereal boxes. The solid-surface countertop and matching decorative backsplash in the galley are illuminated by LED lighting and have a high-end luxury kitchen look and feel. Had it not been for the extendable, pullout cabinet/counter and the sink covers, the workspace would be limited for those heavy cooking days. On the plus side, the kitchen offers more than enough space for all the necessary cooking stowaways. In fact, there’s so much storage space in and around the food prep zone that the two large drawers living under the quick-heating, two-burner Fusion induction cooktop could be easily exchanged for a standard-style oven in addition to the only baking source, a mediocre proportioned Frigidaire convection/microwave oven. While the entire living and galley area is opened up nicely by the slideout, it’s also good to know that access to the back and use of the galley can still be accomplished while the motorhome is in travel mode.

TV and fireplace are built into a stylish cabinet next to the entry door.

TV and fireplace are built into a stylish cabinet next to the entry door.

It seems like the Jayco designers concentrated on good lounging capability when they placed the dinette and couch in the slideout. Not only is the seating area stately-looking with the contrasting light-colored tile floor, but the ability to kick back in comfort and view the fireplace or TV was clearly a priority. The very front is all Class C, with a classic cutaway portion above the cab ready to be converted into a queen-size bed. Assembling the cabover bed uses a unique approach and when done, it’s rated to handle 750 pounds. There are storage compartments on both sides, and if the bed is not needed, the area is a great catchall for bulky stuff that otherwise could clutter up the free-flowing space in the living room.

We were impressed with the positioning of the TV and fireplace, situated in the corner adjacent to the entry door because it helped make a comfy home-like setting in the living room. And most of the seated crowd can have a clear, non-neck-kinking TV watching experience. All the usual sound and video goodies are included, such as Blu-ray player with HDMI connections to all TVs. However, in general, we were less impressed with the specific components in the system and how they were arranged. For the cost of the rig, it could have had better quality TVs that can actually respond to their own remotes. It also wouldn’t hurt if the audio/video switches and panels could be made more user-friendly with easy-to-follow instructions. The nest of wires, switches and boxes can leave you almost clueless and they were visible from the rear portion of the dinette and couch.

The motorhome can essentially be divided into two or three areas. The center bath can be isolated with the use of pocket doors, which makes the bathroom continuous, but blocked off from the living room and bedroom. Close just the front pocket door and the bedroom and bathroom are transformed into a large suite, which is practical when occupants are getting ready for the day or a big event. Another sliding door closes off the smaller room with the porcelain toilet, and the shower stall is placed in a garden-style setting on the opposite wall. The entire arrangement works well and the versatility of using the lavatory sink, toilet and shower independently makes for happy occupants.

 Galley is not overly roomy, but sink covers and the pullout countertop extension help the cook spread out.

Galley is not overly roomy, but sink covers and the pullout countertop extension help the cook spread out.

In the master bedroom is the mother lode of storage cabinets and closets, displaying naturally toned raised-panel doors among the neutral, but flattering Sterling-branded inner accents, trim, and decor. A shallow slideout on the passenger side is appropriately fitted with a dresser with four healthy-size drawers; an LED TV positioned in the cabinet structure is within perfect eyeshot of those lounging on the king-size bed that moves in and out with the third slideout. To any pack rat’s delight, the entire rear wall is configured with a monster-size wardrobe closet, containing five large drawers, a heaping top closet, an optional washer-dryer location/connection and an almost walk-in size closet for hanging clothes. If that weren’t enough, the additional overhead cabinets and nightstands on either side of the bed can take on more stuff. LED reading lights and 120-volt AC power at the nightstands add to the convenience.

Supporting the creature comforts in the Seneca is a long list of standard equipment features and a targeted list of options, including the one that’s mandatory, which includes many of the things most owners will want anyway. A few of the items, like the backup and sideview camera/monitor, dual 15,000-Btu air conditioners with heat pumps, 1,800-watt power inverter, electric awning, on-demand water heater and bigger refrigerator are must-have items in a motorhome of this caliber. Other popular standard accessories include the automatic hydraulic leveling jacks, 8-kW Onan Quiet Diesel generator with auto start and a keyless lockset in the entry door. While it was too warm to test the heating system, we can confirm that the dual air conditioning did a good job in hot, sticky weather.

Jayco-Seneca-SpecsIt’s obvious that Jayco’s attention to detail when building the Seneca contributes highly to the ability of the interior to remain comfortable in just about any weather condition — and relatively rattle-free when on the road. Jayco uses a winning combination of an aluminum-frame structure and vacuum-bonded side walls, roof and floor, with bead-foam insulation rated at R-24 up top, R-9 under your feet and R-8 in the sides. The gelcoat fiberglass exterior walls and roof are smooth, as is the one-piece fiberglass cap. Overall, the fit and finish are clean and precise, and items like dual-pane windows, slideout toppers and the frameless windows (part of the mandatory package) contribute to the build quality.

Outside is a good array of storage compartments that open laterally and an entertainment center with a 39-inch TV and AM/FM/CD/DVD player. The utility center is complete but the dump-valve arrangement seemed to be a little overcomplicated and could use a better road map. However, we did like the Thetford Sani-Con Turbo macerator system for dumping the holding tanks. The heavy-duty 50-amp power cord is controlled, thankfully, by an electric take-up reel mounted in another compartment. Four house batteries are on a slide-out tray for easy service. Those who want to access the engine compartment can do so by lifting the nose of the cab. Once open, the engine service points are easy to reach. Even if you’re not a gearhead, you’ll like boasting to your RV park neighbors about how the engine looks with the hood open.

The Jayco Seneca 37HJ has everything any serious diesel motorhome enthusiast could want. A Super C is not for everyone because it’s in a category that appeals to people who value the robust drivetrain but would rather not pilot a big Class A — and are OK with semicommercial aesthetics. The cabover makes sleeping more versatile, so having the grandkids over for a while, for example, will have little effect on overall livability.

While some people might think dropping 235 grand on a big Class C is far-fetched, in reality the Seneca is built for the long run and those looking for the proven durability of the Freightliner chassis and drivetrain, not to mention the luxury afforded by the high-quality materials and accessories, will appreciate this motorhome.

Jayco Inc  | 574-825-5861 |



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