Product Evaluation: Mack Pinnacle day cab

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Mack Pinnacle day cab specifications (as tested)
BBC: 116 in.
Wheelbase: 191 in.
Engine: Mack MP7 C MaxiCruise, 11 liters, 395 hp @ 1700 rpm, 1560 lb-ft torque @ 1560 rpm
Transmission: Mack T306G, 6-speed manual
Driveline: Dana Spicer
Suspension: Mack MaxLite 40, 40,000 lb, air ride
Front axle: Mack FXL 12, 12,000 lb
Rear axle: Meritor RT40-145A, 40,000 lb, aluminum carriers
Brakes: Meritor
Wheels: Alcoa aluminum with DuraBright
Tires: Michelin, 275/80R22.5 front; Michelin X-One singles, 445/50R22.5
Fuel tank: 93-gallon, aluminum, LH, round

At first glance, Mack’s Pinnacle bears a strong resemblance to the company’s now-venerable Vision tractor. But the similarity belies Pinnacle’s completely new cab, new and repositioned powertrain, steering and suspension enhancements, and clean-sheet interior design.

The package
The Pinnacle day cab has a 116-inch BBC, with a cab that’s 4 inches longer than that of the Vision. The package rides on Mack’s Advantage frame, with a choice of four thicknesses ranging from 6 to 9.5 mm, and a variety of crossmember configurations. It’s a Huck-bolted assembly, using smaller bolts in more places than in previous designs. This makes for more even clamping force and provides more places for frame holes to line up with auxiliary frame-mounted equipment, according to Jerry Warmkessel, Mack’s marketing product manager of highway products.

Pinnacle is powered by the new, SOHC 4-valve MP (Mack Power) 7 engine, which displaces 11 liters, with ratings from 325 to 405 hp, and torque ranging from 1260 to 1560 lb-ft. It’s managed by V-MAC IV, Mack’s latest electronic system that controls fuel, timing, power, idle speed and shutdown, and engine protection; and can interface with the optional Co-Pilot driver display.

The MP7 uses a variable-geometry turbo and, for ’06, is compliant with ’04 emissions regulations, although it will be available in ’07 emissions trim later this year. Mack’s PowerLeash engine brake, which reportedly provides braking horsepower equal to engine horsepower, is standard for ’06 and optional for ’07.

The new engine is available in Mack’s application-specific families: Maxidyne, for high-performance vocational applications; MaxiCruise, for vocational and highway applications; and Econodyne, for fuel-sensitive highway applications. It can be mated to a variety of Mack manual, Eaton manual and automated, and Allison automatic transmissions.

Underhood news
During a brief walkaround, evaluators learned that the Pinnacle’s powertrain had been lowered by 4 inches and moved aft in the frame. Standing on the ground, evaluators noted that they couldn’t see over the top of a nearby Vision’s engine. “The Pinnacle’s is obviously lower,” said one.

According to Warmkessel, the lower powertrain allows for more airflow through the engine compartment. Moreover, in anticipation of ’07 emissions regulations, the company will switch to a close-tip engine-mounted fan shroud to boost airflow even further.

He added that another bonus to the powertrain placement is that it lowers the vehicle’s center of gravity, thereby improving stability. Evaluators later agreed that the setup – in conjunction with new outboard-mounted shocks and dual cab-suspension airbags mounted at the rear corners of the cab – made for a flatter, more stable driving experience.

Evaluation team members noted that all fluid check and fill points, as well as most common service items, were within easy reach from ground level, and they were pleased to see a pad-mounted alternator and A/C compressor, generally considered to be a more durable attachment method. Mack credits input from its technicians and customers for ease of service.

Finally, evaluators appreciated the electronically controlled, modulated, viscous fan clutch, preferring it to the all-or-nothing on-off type. “If you don’t need the fan at full speed, why waste full-fan horsepower,” said Warmkessel. Evaluators agreed.

The proof is in the drive
Evaluators agreed that where Pinnacle shines brightest is in the driving experience, thanks largely to the completely new interior. Ergonomics were found to be first-rate, with a new wraparound dash, clean easy-to-read gauges, standard tilt-and-telescoping steering wheel, adjustable armrests, suspended pedals, an air-assisted clutch and plenty of leg and belly room. “They’ve really put the extra 4 inches of cab length to good use,” said one team member. “I’m used to automatically putting the seat back as far as it will go, but that’s not necessary here.”

Outward visibility was judged to be excellent through the one-piece windshield, the large side windows and optional passenger-side low-mounted window. The large glass area also helps make it easy for fleet safety and enforcement officers to ensure that occupants are wearing their three-point seatbelts.

Evaluators enjoyed what they described as a smooth, quiet ride, and they commented enthusiastically on Pinnacle’s maneuverability, made possible by a wheel cut increased from 38 to 50 degrees. “I thought I might have trouble with that last tight turn,” said one team member, “but I was surprised at how easy it was.”

Also drawing praise – especially on a hot July evaluation day – was the redesigned HVAC system. “That thing really blasts the cold air,” reported one evaluator. “I had to turn it down within the first few blocks.”

Evaluators discovered other nice interior touches, including abundant storage in the overhead console and in-dash compartments, and they appreciated the built-in trash bin and cell-phone and cup holders. They also were pleased to see waterproof floor mats with raised edges designed to channel water toward the door sills, making cleaning an easy hose-out process.

However, Warmkessel told the team, “We’ve had customers tell us that, when they wear a hole through the area around the driver’s pedals, they don’t like having to replace the whole mat. So for next year, we’re providing a still-waterproof mat with interlocking, individually replaceable sections.”

“I’ve always thought that design engineers should first have to work as technicians or truck operators,” opined one evaluator. “But by getting technician and customer input before building a truck, Mack is doing pretty much the same thing. It makes sense – and makes for a better design.”


The fleet operator’s opinion
CCJ Product Evaluations are not performed by CCJ editors. They are done by a team of fleet equipment managers, chosen for their experience with the type of product being evaluated. Editors report evaluators’ opinions, not their own. Comments are not attributed directly to specific evaluators to avoid the appearance of individual endorsement or criticism of products.

An evaluation is based on a driving test and design assessment (which sometimes involves some disassembly of the vehicle), followed by a discussion among the evaluators
and manufacturer’s representative(s). Manufacturers are given ample opportunity to respond to any criticisms.

As always, we welcome your comments and suggestions.

The Mack Pinnacle Product Evaluation Team: Dan Alderfer, assistant equipment manager, Haines & Kibblehouse Group, Skippack, Pa.; Tom Vajdic, fleet maintenance manager, K.L. Harring Transportation & Warehousing, Bethel, Pa.; and Bob Renner, equipment manager, Haines & Kibblehouse Group. Also, from Mack Trucks of Allentown, Pa., thanks to Michael Kline, product manager of product planning, and David McKenna, product manager of marketing for engines, transmissions and axles.