A Very Tall Order
by Jim Park
Engineers don't buy a lot of trucks. That's why Freightliner relied heavily on customer input in designing Cascadia. It's the truck the users told the engineers they wanted. To Freightliner's credit, the customer's wish lists were taken seriously. They started with few assumptions, save for the proven P3 chassis and left few stones unturned in developing this machine. The company invested more than $400 million in engineering and product validation following more than a million hours in development and testing time. If our 408-mile test ride was any indication, Freightliner has invested wisely.
Driver comfort and lower operating costs topped the list of design priorities. We can confirm that Freightliner has delivered on the former, and we think time will prove Cascadia successful on the later as well.
While some other OEMs have been leaning toward sexier, automotive styling, Freightliner has focused instead on what customers want - going decidedly against the grain, in some instances.
The two-piece roped-in windshield, for one small example, is less expensive to replace than single-sheet bonded windshield and requires less than 30 minutes to install. Freightliner's director of product strategy, Chris Hofmann, told highwaySTAR that while the bonded windshield may offer a very slight aerodynamic advantage, customers made it clear they weren't happy about losing a day's work to drying glue.
The list of engineered improvements is a long one, but among the notable:
- the battery box has been moved from between the frame rails at the back of the cab to the driver's side door-step position - shorter cables mean less voltage drop;
- the cab is 20 percent bigger, allowing for a larger door opening and larger seats - with more room between them;
- the cab extenders are much shorter, though equally effective aerodynamically as the traditionally larger ones - they're less prone to damage, and have break-away mounts to prevent damage to the extender itself;
- aerodynamic refinements have the potential for a three percent improvement in fuel economy, Freightliner says. They've closed the gap between the hood and the cab, generally streamlined the exterior of the cab to optimize airflow. They've done some remarkable things with airflow under the hood as well;
- the mirrors were designed and positioned to optimize aerodynamics, and Freightliner says the shape and position of the mirrors relative to the cab will ensure that dirty water doesn't remain on the glass. Visibility remains terrific; these improvements won't go un-noticed by drivers.
- And, it's quiet. Very quiet.
While improved airflow around the cab is responsible for some of the interior noise reduction, other improvements contribute to the nearly automotive sound levels inside. Redesigned front and rear cab mounts, engine mounts, and a hydraulic clutch linkage contribute to the substantial reduction in vibration and noise transmitted into the cab from other components. So, how quiet is Cascadia?
If not now the quietest truck in the road, Cascadia shares first place with another recently launched Class 8, the ProStar. I drove both within a week of each other, and sound meter readings confirm that both these trucks have knocked Volvo off the quiet-cab podium - at least for the time being.
Cruising at 1,300 rpm at 62 mph, my meter read 66 dB(A). My Ford Taurus cruises at 58 dB. I recorded Cascadia at 67 dB in a hard pull (1,400 rpm) and at 70 dB with the engine brake running at 2,000 rpm and the fan on.
In my opinion, the single greatest improvement in this truck is the big radiator.
"Cascadia's appearance is counter-intuitive," admits Matt Markstaller, Freightliner's manager of product validation. "It may look chunky and less-than-aerodynamic to the eye, but wind tunnel testing tells us otherwise. It's all about how we channel the air through the rad and under the hood. It's much better aerodynamically than the visual cues suggest."
The big gain is silence. It's a real plus not having the fan roaring away under the hood - even with the AC on. When the fan did come on, I could barely hear it. In fact, there was less than a 2 dB difference in cab noise levels with and without the fan. The big 1,625-sq-in. rad allows for a much less aggressive fan too. So, with reduced fan-on time and a fan that draws less horsepower, there are fuel savings to be had here. Big aggressive fans can draw as much as 40 hp in some instances.
Clearly, excessive fan-on time isn't something the industry will have to get used to. Freightliner has solved that problem rather deftly. It remains to be seen whether the others will follow its example.
Steering and Gearing
Twenty miles of stop-'n-go traffic is enough to annoy anyone, but that's Portland Ore. at 4:00 p.m. That's when I left the lab with the truck, and surprisingly, I was still smiling when I hauled it into the Flying J at Troutdale for an axle-weight and a coffee on the first leg of the trip. The sweet throttle response of the Cat C15 and the tight gear steps of the Eaton Fuller 18-speed made all that shifting a great deal of fun.
The hydraulic clutch linkage took a bit of getting used to. It doesn't have quite the same engagement feel as a direct-linked clutch pedal - it feels a little dead at engagement. Drivers will get used to it quickly I think, and come to like it.
Armed with my scale ticket and really nasty cup of coffee, I hit I-84 west, headed for Biggs where I'd turn south on US 97, headed for Bend. As Interstate highways go, that stretch of I-84 has to be among the nicest in the land, with loads of twists and turns and modest grades. The Cat made short work of the mostly rolling hills, and the TRW steering gear - mated with the one-and-a-half-leaf front suspension - cornered like a cat with sticky feet.
Even in the dying moments of my drive the following day, coming back to Portland's stupid traffic, I was looking forward to the urban portion of the test so I could shift more gears and turn more corners. I like to drive, and I found this truck very satisfying.
The first real workout for the C15 came at the big hill at the north end of US 97 at Biggs. It's a long climb that steepens near the top, but the Cat didn't even break a sweat. Grossing about 73,000 lb, I pulled comfortably up that one at 1,400 rpm with plenty of throttle left. I upshifted from sixth-over to seventh-over to see if the Cat could claw its way back to peak torque. It did, but with some effort; from 950 rpm back to 1,325. It's not recommended to pull it down that low, given the sledgehammer effect of the torque spikes on the drive line, but it shows the engine does have some reserve below the 1,200-rpm-peak-torque point.
At a modest rating of 475/1650, the C15 exceeded my expectations in every way.
Its published torque curve is flat from 1,000 rpm out to about 1,450. That's what will make drivers like this engine. It just keeps on pulling as the revs drop in a pull, and coming off an up shift at, say, 1,350 or so, it's still firmly in grunt mode. The horsepower starts to roll on at 1,300 where it's making about 400 horses.
Drivers with the discipline to keep it below 1,400 rpm will find little degradation in the performance with suitable fuel economy, Cat says. Operating right there in the cusp between torque and horsepower is where you get the best sense of the engine's capabilities. It sure didn't feel like a 475.
And notably, during those long climbs - even during the mid-day heat - the fan hardly came on at all. And when it did, it was barely noticeable.
The low beams were a little weak at the knees, but the high beams were spectacular. I don't ever recall that kind of night-time visibility before. Al Pearson, director of vehicle testing told me it might have been an adjustment issue, as I found the low beams just a little too tight to the front of the truck for my taste.
I spent the night in the truck in a Wal-Mart parking lot in Bend. I like to sleep in a new truck to see where I bump my head in the dark, or how hard it is to turn off the reading lights at nap time. The Cascadia sleeper gets full marks for convenience and comfort, though the sliding windows in the sleeper still need a little work. The latches are awkward, and require two hands to get them open.
Getting in and out of the driver's seat is a cinch, though I'd omit the cup holder mounted on the floor aft of the gear shifter. I tripped over that a couple of times. The position of the gear shifter didn't obstruct egress from the seat at all. And with 21 inches between the armrests, and 38.5 inches between the cabinets in the bunk, there's no shortage of room inside the cab and sleeper.
Visibility in Cascadia is remarkable; big windows, fine mirrors, and low hood crown. In all other respects, Cascadia is what truck drivers will take to. It's big and roomy, it's quiet, and it rides and handles like a charm. What's not to like?
Buyers who remain emotionally detached from the asset acquisition process will appreciate Cascadia's engineered improvements and inherent operating economy. It's designed for comfort, efficiency, and low cost of operation. The cab is unbelievably quiet and roomy, and the ride is terrific. It was designed to keep maintenance and repair costs to a minimum while offering substantial fuel savings through its wind-tunnel-proven aerodynamic superiority.
As for the big radiator, it's likely that we'll see higher displacement engines come our way in 2010 as a means of complying with the 2010 emissions reductions. The big rad could be a necessity in a few years. In the meantime, given the choice between Cascadia's large-ish rad, and the near-constant roar of a very aggressive fan behind a smaller rad, I'll take the big hole in the nose any day.