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BEST-IN-CLASS SOUND QUALITY PACCAR MX, PETEBILT MODEL 579
A Quieter Ride
Achieving best-in-class sound quality
starts in the chassis
Complementary Partners
PACCAR MX, Model 579 pairing is right
for a variety of applications
Putting the driver in a quiet
operating environment starts
with eliminating common
vehicle noises at their source,
more so than merely building a better
wall to fend them off, according to
Peterbilt engineers.
To that end, when Peterbilt engineers
targeted best-in-class in-cab
sound quality as a priority, work started
from the road up.
A brief primer in Sound 101 will help
explain why. Sound is essentially the result
of something moving or vibrating, and
that movement causes a resulting disturbance
in the air, which our ears recognize
as sound. In the cab of a truck, minimizing
or eliminating vibration or movement
of the chassis, therefore, reduces a primary
source of in-cab operating noise.
“We spent five months analyzing
sound inputs and eliminated many of
these inputs in the design process,”
says Peterbilt Senior Assistant Chief
Engineer Kevin Baney. “Textbook
design is to stiffen the chassis
and the cab and have
softer mounts to isolate
the noise.
“We did just that —
A tight chassis proved to be the key in
achieving best-in-class sound quality for the
new Model 579 .
made the chassis and
the cab very stiff. And we adjusted mount
isolation to minimize noise transfer to the
cab from the chassis.“
Baney says the chassis design of the
Peterbilt Model 579 includes use of an
“overbell”, a unique crossmember that
strengthens the chassis at the cab mounts.
The result is a cab that improves chassis
stiffness by 100 percent over commonly
employed chassis stiffness standards in the
industry, according to Baney.
Noise dampening plays a key part in
quieting the cab environment, according
to engineers, and
new technologies
were a factor in driving the
Model 579 to its sound quality goal.
“Noise is still going to come from
the road, the tires, the powertrain, up
through the chassis,” Baney says. “The
key is to manage and control what
reaches the driver’s ear. The remaining
noise was dampened through treatments
on the engine cover, floor and
cab/door panels.
“But we only added it where
absolutely required.”
New standard
Engineers determined where best to
place the materials and how much was
necessary to maximize weight savings and
still achieve best-in-class status.
The result? A cab that set a new bestin-class
standard for the industry, by
nearly two decibels.
“It starts with eliminating completely
the source of the noises that normally
reach the driver’s ear,” says Baney. “Those
noises that survived, we dampened out
with innovative treatments. So whether
you’re closing the door or rolling down
the highway, you’ll hear luxury car levels
of sound quality.
“It’s a smart design.” FC
Pairing the two most inventive
trucking innovations of recent
years is the best way to optimize
the performance benefits
of the new Peterbilt Model 579 and the
PACCAR MX engine, according to
Peterbilt officials.
“The PACCAR MX and the Peterbilt
Model 579 are both engineered to deliver
industry–leading performance, reliability
and fuel efficiency,” says Peterbilt General
Manager Bill Kozek. “There is simply no
better way to optimize the performance
benefits of each of these innovations than
to run them in tandem. They provide an
outstanding complement to each other.”
Multiple advantages
For example, both the PACCAR MX
and the Model 579 are engineered for maximum
fuel economy. The Model
579’s aerodynamic design is best-in-class,
and the MX has been producing impressive
MPG figures for numerous customers.
And innovative weight-saving design
considerations in both the PACCAR MX
and the Peterbilt Model 579 illustrate the
synergy of pairing these two
products, according to Kozek.
The MX employs Compacted
Graphite Iron, which is 20
percent lighter than traditional
gray iron. The compact yet
versatile 12.9-liter design
belies its efficient size and can
produce a horsepower range of up to 485
hp and torque outputs to 1,750-lb-ft, outperforming
larger and heavier alternatives.
The Peterbilt Model 579, meanwhile,
is equally thrifty in weight savings.
Lightweight, stamped-aluminum construction
of the cab means the
Model 579 is well-rooted
in the basics of
weight efficiency. Use
Constructed of Compacted Graphite Iron,
the PACCAR MX engine maximizes the
weight-savings and fuel economy benefits of
the Peterbilt Model 579.
of high-quality composites reduces weight
in the hood and fairings. And Peterbilt
engineering, which is evident in components
such as their proprietary Front Air
Leaf suspension, delivers weight savings
from numerous sources.
“There is simply no better way to
optimize the performance benefits
of these innovations than to run
them in tandem.”
Similarly, a PACCAR MX-Peterbilt
Model 579 combination maximizes durability:
the PACCAR MX has a B10 design
life of 1 million miles, and Peterbilt has
spent years and more than 2.2 million
test miles refining and perfecting robust
design elements that figure to give the
Model 579 a similarly long service life.
Resale considerations
And such durability features of the
PACCAR MX and Peterbilt Model 579
are likely only to enhance Peterbilt’s
industry-leading reputation for resale
value, as the secondary market will know
there’s plenty of life left in a pre-owned
MX-579 combination.
“It is often said that the whole is
greater than the sum of its parts, and I
believe that is certainly true when you
pair the PACCAR MX engine with the
Peterbilt Model 579,” says Kozek. “They
are uniquely complementary partners,
and in combination, provide extraordinary
value and performance to the fleet
owner and driver alike.” FC
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