Test Drive: Mack Pinnacle

| August 07, 2007

The MP8 is also prepared to handle tighter emissions regulations. All gearing has been moved from the front to the back of the engine. This narrows the engine’s front, allowing for more airflow and greater cooling, and it also puts the gearing near the flywheel, decreasing engine vibrations. Remove four bolts under the dash to access the rear of the engine from inside the cab. The MP8′s crankcase breather has a filter so its fumes comply with ’07 emissions regulations.

Along that line, Mack cleans the MP8′s exhaust with cooled exhaust gas recirculation.

The aftertreatment system includes a diesel particulate filter, the heart of which is a platinum-coated ceramic catalyst. The Pinnacle has two optional DPFs, both vertical: the MackCap, just forward of the passenger-side fuel tank, and the Back-of-Cab model. Both last the life of the engine and will last 150,000 miles before service.

Mack is up front about the system’s cost.

“The kind of engineering that went into these vehicles is not free,” says Vice President of Marketing Tom Kelly. “A cleaner environment is also not free, and I won’t apologize for that.”

Kelly says Mack’s costs for meeting EPA standards “will be competitive” – roughly $8,000 per truck, he says, then adding: “A street price really hasn’t emerged yet.”

But consider the fuel mileage you’ll get in this truck: on this trip, 7.9 mpg, according to the Pinnacle’s driver information screen. This is impressive, considering we were at 70,000 pounds and running hard through the mountains northeast of Las Vegas.

I continued north on I-15, growing more impressed with the MP8′s pulling power and engine brake. At the first exit ramp across the Arizona state line, I let the PowerLeash slow the vehicle to about 30 miles an hour before I feathered the throttle so we’d make it to the stop sign.

I stopped for some photos, then headed back down the only hill the PowerLeash could not handle on its own (air-brake assistance was required).

But the MP8 continued to perform. I’ve driven engines with ratings of 300 to 600-plus horsepower. The general rule is that 415 will get a heavily loaded truck through the mountains, but it’ll slow down on the steeper hills.

Apparently the MP8 hasn’t heard that rule. I set the cruise control at 75 again. It was about 2:15 p.m. We were 80 miles from the endpoint and were due back by 3:30. We arrived 10 minutes early.

Test Drive Specs
Truck: Mack Pinnacle Axle-Back 70-inch high-rise sleeper
Engine: 415 horsepower Mack Maxicruise MP8
Transmission: Eaton-Fuller fully automatic 10-speed Ultrashift
Rear Axle Differential: 3:73
Front Axle: Mack FXL 12,000 lb.
Suspension: Mack MaxLite 40 EZ Air Ride
Wheelbase: 239 inches
BBC: 112 inches
Interior Trim: Cobalt Blue Cloth/Ultraleather
Tractor Weight: 19,300 lbs.
Tractor/trailer Weight (empty): 33,960 lbs.
Tractor/trailer Weight (loaded): 69,920 lbs.
Fuel Mileage: 7.9 miles per gallon
Test Drive Length: 200 miles

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