VT 800 Has A Lot Of Pull
By Jim Park
Contributing Editor
Driving Volvo's big new VT 880 with its impressive D16 engine is a bit like holding onto a tiger by its tail. You need to be real careful what you do with it. Six hundred and twenty five horsepower and 2,255 lbs.-ft. of torque will get you anywhere you need to go, quickly, but it could eat you alive along the way.
The people over at Volvo Trucks North America recently arranged a test drive for a small flock of trucking journalists to show off the D16's ample torque, which is what really makes the truck shine. We ran three trucks (two 625s and a 550) north out of Volvo headquarters in Greensboro, N.C., on Highway US 52 toward Mount Airy, and then up I-77's Fancy Gap hill. From there, we strolled along I-81 to Bristol, Tenn., and then south on US 19/23 into Asheville, N.C., where we holed up for the night on the grounds of the 8,000-acre Biltmore estate - the ancestral home of railroad pioneer George Vanderbilt.
The Volvo crew checked into the five-star hotel located on the grounds, while the motor-noters stayed in the trucks - by choice. But we weren't hurting either. The housekeeping people came out to the trucks and set lovely tables for us in the fold-out dinettes, and made up our beds. Heck, they even left little chocolates on our pillows. If only, eh?
Day 2 was a leisurely trip back to Greensboro, eastbound on I-40, notorious not for large grades but for rolling hills that demand lots of shifting from lesser engines.
Hills were the main item on the agenda, and the route the Volvo people chose had lots of them. Not that it mattered - the D16 made short work of them all.
Torque is the key to this engine's hill-flattening power. In the Scandinavian countries where the D16 was born, trucks haul up to 132,000 pounds on eight axles, and road-speed is limited to 55 mph by law. They can't improve transit times by going faster, so the alternative is to make time on the hills where a slow pull might otherwise cost them. The D16 can pull a substantial grade losing only a bit of speed, hence, faster trip times. Here in North America, speed has been king for years, so we're not used to thinking of engine output in terms of torque. But when you see and feel what torque can do for you, you'll be hooked.
It's About Torque
Imagine pulling Fancy Gap - loaded to 78,800 pounds - at 50 mph. That's what I did in the D16. I pulled the hill in 7th-low, from a dead stop, coming out of the rest area at the bottom of the hill. I ran at 1,100 rpm all the way to the top - right at peak torque.
It may seem counter-intuitive to pull a big hill like that while backing off the throttle, but the idea is to keep the boost pressure as low as possible. At low rpm, 20 psi of boost was all I needed to maintain road speed. The engine was working hardest at its most fuel efficient.
It wasn't running hot either; in fact, the fan only came on once for about a minute. In the past, I might have pulled that hill in a gear that would have given me 1,700 or 1,800 rpm - enough engine speed to keep the coolant circulating, and the exhaust temperature low. That about explains the biggest difference in recent vintage big-torque engines: They're designed to run at low rpm. And, contrary to popular belief, you can't hurt them by "lugging" them. Low rpm is where they do their best.
On the other side of the power scale, the D16's 625 hp was more or less lost on me. I'm not a fast driver by nature, and so I'm not inclined to take advantage of its substantial horsepower. It strolled along at 65 mph quite comfortably, and went to 80-plus with ease. But speeds like that demand a high rate of fuel input, which precipitates a high rate of cash output - just not my style.
At the end of the trip, we fueled the two six-and-a-quarters to get an economy reading, and both managed a reasonable 5.33 mpg over the rounder.
Brawn and Brains
As you might imagine, 2,250 lbs.-ft. of torque spun through a 14.4:1 ratio in low gear can get the driveline people sweating. Not so with Volvo's Intelligent Torque management system. Torque is at its most valuable in maintaining roadspeed in the upper gears. It's just not necessary in the lower side of the gearbox. I-Torque electronically limits torque output in the lower gears (low-3rd) to 1,850 lbs.-ft.; 2,050 lbs.-ft. in the middle gears (3rd-high to 5th-low); and opens up to full output in the remaining gears.
Output varies with the engine rating, but the principle is the same: output is limited when it's not needed to protect the driveline. This makes a lighter driveline possible, saving the customer weight and money.
I ran the 550 up Sam's Gap hill, and while the big D16s beat me to the top, soundly, I wasn't exactly struggling to make the crest. Sam's Gap is a 10-mile climb, the first eight hardly noticeable, rising only 500 feet or so, but it still takes the wind out of your sails. The final two miles climb about 1,500 feet. I had the 550 pumping out peak torque of 1,850 lbs.-ft. at 1,000-1,100 rpm. I'd estimate the big engines beat me to the top by a minute or so, and maybe a gear or two, but my "little" truck still made a respectable showing.
Brains and Brawn
I'd be remiss if I didn't mention the other side of the D16. Power like that used wisely can be very advantageous; used without discretion, it could bite your backside right off - starting with your wallet. At 5.33 mpg, it's hardly a record breaker, but the engines weren't even broken in yet. Conceivably, a smart operator could squeeze at least another mile per gallon out of it. The risks lay in the less than professional driver using the massive power to propel the thing down the road at excessive speeds, thereby negating the benefit of its huge torque output.
It was designed to pull. That it can go fast too is a side effect of the way diesel engines work. So, operators who want to make their jobs easier by eliminating a lot of gear shifting, or climb hills faster by using torque to their advantage could profit from owning an engine like this.
We can make a pretty solid case for the D16 here in Canada, with our tridems, quads and super-Bs. That's a lot of weight to drag around, and having the power to do it can only be seen as a plus. Again, the principle advantage to an engine like this is having the power to pull the weight against a prairie headwind or the rolling terrain in New Brunswick, not necessarily making all that weight go faster.
On many occasions during the trip, we'd begin a short climb on a rolling hill. Almost instinctively, I reached for the splitter as the revs began to drop, then checked myself, deciding instead to let the D16 pull - like it was designed to do. Sure enough, from a cruise speed of 1,450 or so, the revs dropped to around 1,200 or 1,100 and the thing just hunkered down and pulled me over the top.
Even on Fancy Gap, I was able to upshift from 7th low to 7th high on the flattish section about mid-way up. I was gaining ground there, too, but had to drop back to 7th low when we got into a steeper section. Anyway you look at it, if you let the engine work to its potential and manage road speed in accordance with where the engine works most economically, you'll be money ahead. Even with its inherently good aerodynamics, the VT 800 will cost more to run at 75 than at 65 - the same applies to any truck, really. What you're prepared to pay for speed is up to you. Having the power when it's needed is a plus, and managed properly, it won't cost a bundle more to run.
That Big Hood
The big hood is a feature new to Volvo. In the design work, Volvo says they wanted to blend innovation with tradition in a way that would appeal to the modern owner-operator's desire for a distinctive and individual image. It does that, but it also cuts the air pretty effectively too.
The three-piece bumper wraps around the front wheels, improving airflow around the front of the truck while helping with the cooling chores. It's small stuff, visually, but it makes a big difference.
As well, in introducing the D16 to North America, Volvo knew it was going to need an efficient cooling package, including a large rad. The rad on the VT 880 extends from just above the lower edge of the bumper to the top of the hood. Even in the North Carolina heat on a long pull like Fancy Gap, the fan-on time wasn't anything unusual.
From the street, the hood looks large. From behind the wheel, it's surprisingly unobtrusive. Visibility suffers just a little on the right front corner down by the wheel, but it's nothing a fender-mounted convex mirror wouldn't cure.
Meanwhile, behind the firewall, the VT 880 is everything Volvo owners and drivers have come to expect. Safety and comfort topped the list in the design stages with engine mounts designed to collapse in a front-end impact, preventing the engine from winding up in your lap. That also absorbs a terrific amount of energy, making the impact of a crash less severe for the occupant. There is even a pair of impact absorbing knee pads built into the dash to minimize injury in a frontal crash.
From a comfort standpoint, the VT 800 has it all: room, storage space, warm spacious interior colors and trim, and well-designed cabinet door latches to keep all the stuff where it belongs. While I prefer a smaller cab, I can find no fault with the Volvo interior. There's enough room to swing a cat - if you'll pardon the expression - and a pair of drivers could co-exist easily in a space like that.
Perhaps the most remarkable feature of the VT 880 cab is the absence of noise. It was possible to maintain a conversation even with the windows open at highway speeds; close the windows up and you've got sound-studio quiet, almost. If you want quiet, here it is.
Out on the Boulevard
Before we left headquarters, I noticed that the shorter of the three trucks - the one with the 550 under the hood - had the 5th-wheel set to center between the drive axles. I questioned whether we'd scale it legally. The scale ticket showed 11,800 pounds on the steer axle and 33,400 pounds on the drives. Legal - and smooth. The VT 880's front-axle position is nearly a foot ahead of the VN 780's; the cab is set back eight inches from it's traditional position. This makes for better balance, a lighter front-end, and optimal 5th-wheel positioning. And it boasts a 45-degree wheel cut for tighter cornering.
What else could a driver want? Sure and solid handling maybe? Volvo delivers here too. The thing handles like a cat with glue on its feet, really. At several points along the way, weaving through a turn or coming off a ramp and powering up to highway speed, the combination of sure-footedness, solid power and the smooth-shifting Eaton 18-speed gave the big VT 880 the feel of a much smaller and nimbler sports car. There were several moments like that, and with all that conspires to make a driver's life difficult, it's nice to have that small stuff to savor when it all comes together.
The winner in the trucking game isn't the driver who gets to the bank first. It's the one who gets there with the biggest deposit. This truck can do either, I suspect, making it a terrific tool for the right driver, and a tiger for those easily led by temptation.
