Volvo Sleeper Cab Means Off-Road Rest

Sept. 28, 2010

Most vocational trucks like dumpers, mixers and bulk-hauling tractors use daycabs because sleeping is not part of their drivers' usual routine. But some of these extra-tough vehicles venture far enough off-road that drivers must take rest breaks and overnight stays in place, and for them Volvo Trucks has its new VHD 430 with a short sleeper compartment and roomy bunk that makes layovers legal.

This ruby-red tractor is among the first such tractors produced, and its chrome and bright-metal trim suggests that it was built for show as well as for going — to Canada, where loggers are among the truckers who can use on-board sleeping accommodations. The vehicle was temporarily working at Bendix Commercial Vehicle Systems' shop near the Transportation Research Center's sprawling complex northwest of Marysville, Ohio, which is maybe 40 miles from my home, so I sought some seat time in it.

Bendix technicians had been using the tractor to calibrate settings on their electronic Roll Stability Control, part of ABS that helps prevent rollovers; they hitched up a test trailer whose outriggers — which, when deployed, keep an aggressively cornering rig from turning over — had been stowed for highway travel. The rig was ready to go when Volvo product manager Frank Bio and I drove up.

We departed soon after checking in with no particular route in mind, and I decided to use more two-lane highways than freeways. It was quickly apparent that this tractor rode almost as nicely and was as quiet and comfortable as Volvo's limousine-like VN highway tractors. Of course, the VHD (for Volvo heavy duty) has a stronger chassis meant for on/off-road rigors. It might not be high on vocational truckers' lists of trucks to consider, but it ought to be, for it's arguably good looking, both in photos and in actuality, with stout yet curvaceous lines that at once suggest toughness and modernity.

And this one showed a major improvement in an area on which I tend to focus, which is shift quality. Most Volvos I've driven have not been good in this respect, and "rubber lever" is among the expressions a Volvo driver might use in describing his regular ride. So here I am in this VHD 430 and its Fuller 18-speed, going through all of the nine main gears smoothly, float shifting without the clutch once in a while and splitting gears for the fun of it. "What's the deal with this gearshift?" I asked Bio later in the run.

"They made a change in the shift linkage, but it actually was done to get the shift lever further to the center, to get it out of the driver's way when he heads for the sleeper," he said. The lever's base is now in the center of the wide cab instead of offset to the left; it's now bent to put the knob close to the driver, but has a solid feel. "Moving the lever required a change in the linkage, and a side benefit is the easier shifting. I don't know exactly what they did to the linkage, but it works better."

It sure does. And being able to shift easily and smoothly helps a driver's confidence in other areas of operating the truck — for instance, turning through tight intersections without worrying about whacking cars in other lanes. I made several such maneuvers in small cities in central Ohio, for we followed state and U.S. highways much more than Interstates. Never once did I feel stressed while driving this rig, not even when a lady motorist had to back up a bit to let me finish a hard right turn in a really tight corner. I waved a thank-you and we went merrily on our way.

The VHD doesn't have a really tight turning radius because its wheel cut is somewhat limited. This is a function of its higher-rated front end — the steer axle at 20,000 pounds and suspension at 16,500 pounds, rather than the common 12,000 pounds in a highway tractor — and there's not enough room for the tight wheel cut you find on some road tractors, including the VN. The VHD's not by any means clumsy, but I did need a little more room while turning.

Strong power and torque were always on tap from the new D13 diesel, the only engine available on the VHD. Its displacement is 12.8 liters (about 782 cubic inches); and this one was rated at 485 horsepower and 1,650 pounds-feet, but like most Volvo engines, feels stronger than its numbers suggest. It provided brisk (for a big rig) acceleration. One feature central Ohio lacks is mountains or even big hills, so I can't say anything about how the engine pulls long, steep upgrades.

The D13-485 makes its peak torque from 1,025 to 1,500 rpm, and power meanwhile ramps up toward its maximum; that begins at 1,600 rpm and continues to 1,900 rpm, and falls off as the 2,100-rpm redline is reached. But it's best to upshift at 1,600 to 1,700 or even lower to get better economy, according to Volvo's engine people. The combination engine and exhaust brake didn't get much of a workout, either, but they did do some of the service brakes' work as I approached traffic lights and stop signs.

Of course, the D13 was an EPA '07-spec diesel, with an advanced, electronically controlled combustion system that burns fuel so cleanly that you can't see any smoke or smell any odor. Among the equipment is a diesel particulate filter that grabs any soot that gets out of the cylinders; the "compact" filter, looking somewhat like a big coffee urn, is tucked under the cab behind the passenger steps, and from there the tailpipe runs up the cab's rear wall near the corner. The end of the stack is perforated for about a foot and a half, which dissipates high heat during DPF regeneration; this might prevent lighting a tree afire while parked in the woods (this is a logging truck, remember?).

The driver learns of a "regen" through the LCD information display about the steering wheel on the instrument panel. An active regeneration began as we approached a country intersection, and I pulled off to photograph it. Otherwise, there's no indication performance-wise, and an indifferent driver can just motor along without worrying about it, unless he parks where the hot gas (up to 1,200 F, engineers say, though it's probably less by the time it runs through the long tailpipe, even without the perf-type diffuser) could light a tree afire.

You might think that the intricate passages inside the filter would choke off the engine, but they don't. The engine's designed to work with it and does so very well, at least from the driver's perspective; not enough of these new diesels are out there yet to establish a reputation regarding reliability and longevity, but we'll eventually find out.

Because this truck was built for Canada, the speedometer's primary numbers showed kilometers per hour while miles per hour were in smaller yellow numbers. That way, the driver can watch his speed no matter which side of the border he's on and how the limits are posted, and can see that when the speedo's needle rests on 100 kph, it really means 62 mph. Furthermore, a Canadian football field's length is still 110 yards, not metric meters, thanks to the good ol' standard units of measure. Some things endure.

As should this VHD. It appeared stout and tight and was certainly quiet, smooth riding and comfortable, and was enjoyable to drive. Its interior was a combination of simple design and nice fabrics and well-fitted plastic panels. Most drivers would appreciate working in a place like this, and I sure did, if even for just a few hours. Next time I might not give it back.

All chromed up and ready for work or show, the VHD-430 sleeper-cab tractor poses with its outrigger-equipped test flatbed. A shiny grill covers the 1,280-square-inch radiator needed to cool the EGR'd EPA-'07 diesel.
A D13 diesel, the only engine offered in the VHD, makes up to 485 horsepower and 1,650 lbs.-ft.
The cab's interior is nicely trimmed, and repositioned gearshift lever allows smooth operation.
A diesel particulate filter is hidden behind passenger steps, while the tailpipe winds up the back of the sleeper-cab; the perforations at the end of the pipe diffuse hot exhaust gases, especially during DPF regeneration.
Test Set

Tractor: Volvo VHD64BT430, 6×4 conventional-cab w/43-in. sleeper, BBC 145.6 inches, on 11.81-in.-high × 3.54-in.-flange × 0.38-in.-thick straight-rail main frame

Engine: Volvo D13, 12.8 liters (782 cu. in.), 485 hp @ 1,600 to 1,900 rpm, 1,650 lbs.-ft. @ 1,025 to 1,500 rpm, w/engine and exhaust brake; EPA-'07 legal

Clutch: Eaton Solo 16.5-inch 2-plate, 9-spring

Transmission: Eaton Fuller RTLO-16918B, 18-speed

Front axle: 20,000-lb. Meritor FL941 on 16,500-lb. multi-leaf springs, w/TRW THP60 integral power steering

Rear axles: 46,000-lb. Meritor RT-46-160 w/locking differentials and 4.10 ratio, on Hendrickson Primaxx air-ride

Wheelbase: 269 inches

Brakes: Meritor Q+ S-cam drum w/ Bendix ABS and automatic traction control

Fuel tank: 70-gal. 22-in.-diameter polished aluminum

Tires & wheels: Michelin 11R24.5 on Alcoa Dura-Bright polished aluminum discs

Fifth wheel: Conmet Simplex II on 24-inch slider

Trailer: 48-ft. flat w/test outriggers