Big Dog

By on March 1, 2011
RoadKing Mag

It’s been more than three years since the last time I was in a (then) new Mack Pinnacle. Mack was starting a serious effort to capture a larger share of the over-the-road, owner-operator market. It is best known for rugged, heavy duty vehicles, virtually owning the concrete mixer market, but the requirements for success in construction are vastly different than for on-highway.

In my 2007 review of the model year 2008 Pinnacle, I concluded that “Owner-operators who may be considering an efficient truck should take a good, long look at the Pinnacle. It’s a surprisingly refined evolution.” Since then, the evolution has progressed even further.

The things that impressed me then continue to impress. Bendix Road Stability Advantage (RSA) is standard. Its sensors analyze all vehicle motions, and then compare them to the positions of controls in order to determine driver intentions. When conditions exist that can cause a spinout, plowing, a jackknife or a rollover, RSA de-fuels the engine and applies brakes individually and selectively to bring the truck back to a normal attitude.

How many of us have entered an off-camber turn or a decreasing-radius exit ramp? My guess is that each of us has had a bit of a scare sometime in our careers. I know I have. RSA works at the speed of computers. In most cases, it works so fast and so smoothly that unless you’re actually trying to overcome the laws of physics, you’ll never know the system is working. You never get the feeling that computers are driving the truck, because except for extreme cases, you are in command.

During a product demonstration with a specially equipped trailer in a wide, unobstructed parking lot, I accelerated and then cranked the wheel hard over. I even kept the accelerator to the floor. RSA cut the fuel and applied only the brakes needed to halt the jackknife before I could sense that it started. With RSA turned off, the same maneuver clearly demonstrated why the test trailers were equipped with outrigger wheels. Otherwise, the trailer would have rolled over and snapped the tractor over with it.

Another optional safety feature that I’d love to see standard on all trucks is adaptive cruise control. Mack’s system uses sonar, a technology virtually unaffected by weather conditions within the system’s functional range. The adaptive part of the system ties into the Bendix RSA and Mack’s PowerLeash engine brake. An object is detected, analyzed and determined to present a danger. Then, instantly, adaptive cruise control will de-fuel the engine to adjust closing speed. If necessary, it will apply the retarder. If that isn’t enough, it will apply the service brakes. Appropriate warnings, both audio and visual, alert the driver at each step. While I don’t usually like computers taking over full control, I’ve read about enough drowsy driver crashes that under certain circumstances, I wouldn’t mind the truck coming to a full stop by itself if necessary.

The last Pinnacle I drove had the all-new-for-2007 Mack MP8 13 liter engine, with 1,700 lb-ft of torque at only 1,100 rpm. The Maxidyne (higher power version) engine delivered 485 hp at 1,550 rpm and maintained it through 1,900 rpm, 100 rpm more than the Econodyne’s (better fuel economy version) maximum. The torque was flat from 1,100 through 1,550, and even at 900 rpm, there was 1,400 lb-ft, enough to make up for my missed shift and a catching one gear too high.

I didn’t have to worry about missing shifts with the new two-pedal (no clutch) mDrive 12-speed automated transmission. For the 2011 model, both the direct drive (14.94:1 low gear, 1.00:1 high gear) and overdrive (11.73:1 low gear, 0.79:1 high gear) models can be mated to Mack’s highest rated MP8 with 505 hp and 1,760 lb-ft.

Both versions have electronically controlled variable geometry turbochargers. The Econodyne’s EconoBoost feature adds up to 200 lb-ft to keep you in the highest gear possible while maintaining optimal fuel economy. Mack claims that when driving in rolling country, EconoBoost improves mpg by as much as 1.5 percent.

Rolling country may be typical or “average,” but driving in and around Allentown, Pa., the hills are anything but “rolling.” The Pinnacle was very responsive and handled the hills well. Some of them are as steep as 6 percent. On Mack’s test truck, I pulled smoothly from a dead stop on a 15 percent grade. The truck also was comfortable, stable and, most of all, quiet on a variety of road surfaces, from smooth Interstate to two-lane roads to ramps and streets in need of maintenance.

Driving economically was made far easier using the Mack’s CoPilot driver display. Among its 50 optional programmed screens, you can view real-time fuel economy, performance against target mpg and a sweet spot indicator, showing where you’re driving in relation to the engine’s most economical driving range.

When doing my pre-trip walk around, I noticed the Mack hood ornament, the classic bulldog. Instead of the familiar chrome, this one was gold. Mack fans know this, but I learned it signifies that all components that can be — engines, transmissions, suspensions, axles, etc. — are manufactured by or proprietary to Mack. While many decry this as lack of choice, I see the trend to vertical integration as allowing engineers to concentrate on making components work optimally together. With fewer outside choices, manufacturers use their limited resources to assure performance and eliminate problems. And with Mack, the resultant truck works very well. If you haven’t driven a Mack for a while, test-drive the Pinnacle. You’ll be pleasantly surprised.

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