Test Drive

Jack Roberts | May 01, 2012

The clean, more compact front cab design, Weiblen says, facilitates a nice flow between the front of cab and the sleeper. In the rear, drivers will find a sleeper outfitted with a work station and hook-ups for flat-screen TVs, laptops and video game consoles, as well as tons of storage space.

I spend a good portion of our drive using the passive cruise control, one of many safety and awareness systems. It radar-tracks vehicles in front of the tractor and adjusts my speed accordingly.

Weiblen says the 579 engineering team used the latest composites and ride-dampening technology on the cab. As quiet as the truck is at rest, it’s amazingly quiet even at full-throttle. The overall design has a lot to do with this, but also the aerodynamic exterior virtually eliminates wind noise. With the windows up, interior noise levels in the 579 are approximately 69 decibels — and those levels don’t rise much at all with the windows down, still plenty low at 65 mph to carry on a normal conversation with your passenger.

The all-new chassis and suspension have taken almost all the lateral sway out of the equation, making for sure-footed handling. The truck doesn’t wander around its lane at highway speeds, even with an occasional blast of wind.



Engine: PACCAR MX13

Horsepower: 455 hp at 1,900 rpm

Torque: 1,650 pound-feet at 1,100 rpm

Transmission: Eaton-Fuller UltraShift Plus automated manual

Cab configuration: 123-inch BBC/63-inch hi-rise sleeper

Front axle: Dana Spicer E1202I rated at 12,000 pounds

Front brakes: Dana Spicer air disc

Rear axle: Meritor RT-40145A rated at 40,000 pounds

Rear brakes: Bendix 16.5×7 cam drum

Rear axle ratio: 3.07


A driver-customized interior

Overdrive Executive Editor Jack Roberts samples the results of Peterbilt’s intensive research on ergonomics.

Designer Andy Weiblen he says the five-year development cycle for the Model 579 was driven by Peterbilt’s most intensive market research ever.

“One of our projects was to take a fully adjustable truck cab and sleeper to truck stops all around the country,” he says. “We invited drivers into the cab and sleeper and asked them to set any component in the mock-up exactly where they would want it if they were designing their own personal vehicles.”

Drivers could adjust armrests, bunk heights, interior cab width or seat positions, among other features. The result, Weiblen says, was a gigantic database of real-world ergonomic data. “We were able to use that information to design a truck that is remarkably comfortable for a remarkably wide range of drivers,” he says.


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