With a class
leading 325-horsepower and 560lb-ft of torque, the 6.0-liter Power Stroke
V8 turbo diesel engine is a marvel of design and engineering. "This
engine has been over 5 years in the making," according to Super Duty
Marketing Manager Tim Stoehr.
Several technologies
play heavily in the new Power Stroke's construction.
The electronic
variable response turbocharger (EVRT) on the Power Stroke uses a set of
pivoting vanes that surround the turbine to optimize and control an almost
infinitely adjustable airflow to the turbo compressor. When traveling
at high speeds, climbing steep grades or at altitude the vanes close together
to route more airflow through the turbine. At low speeds the vanes open
to provide better engine response.
Generation
2 (G2) fuel injectors are combined with increased hydraulic rail fuel
injection pressures to better manage fuel before it enters the Power Stroke's
combustion chambers. G2's smaller injectors allow enough room to accommodate
four valves per cylinder, two more than the 7.3-liter
Power Stroke had. The combination of higher fuel pressure and four valves
per cylinder better atomizes the fuel air mixture for improved combustion,
resulting in a quieter engine, reduced emissions and increased fuel economy.
Exhaust Gas Recirculation (EGR) routes a predetermined amount of the exhaust
gas into a cooler where the exhaust gas temperature is lowered. The cooled
exhaust gas is then mixed in the combustion chamber with fresh air and
fuel. The result is lower Nitrogen Oxide emissions.
To help with
maintenance a top mounted oil filter is accessible and easily replaced
during normal oil change service. "The cartridge-type oil filter
is modeled after the toner cartridge you might find in a laser printer,"
said Stoehr. The placement of the filter is important to those of us that
prefer to do our own maintenance.
The Super
Dutys we drove were equipped with the all-new, optional 5-speed TorqShift
automatic transmission. The TorqShift was designed lock-in-step with the
Power Stroke and is a direct response to the Allison 5-speed offered on
the Silverado and Sierra HD pickups from GM. It's no wonder that the TorqShift
and Allison have very similar ratios. Dodge does not offer a comparable
transmission on its trucks. See chart below:
Gear
Position
TorqShift
5-Speed
Allison
5-Speed
First
Gear
3.09
to 1
3.10
to 1
Second
Gear
2.20
to 1
1.81
to 1
Third
Gear
1.54
to 1
1.41
to 1
Fourth
Gear
1.00
to 1
1.00
to 1
Fifth
Gear
.71
to 1
.71
to 1
Reverse
2.88
to 1
4.49
to 1
When comparing
these transmissions on paper the Allison and Ford are nearly identical
in first gear. The fourth and fifth gears are identical with the Ford
TorqShift having the advantage in the critical second gear and a slight
advantage in third. The Allison has the advantage in reverse which is
important when backing heavy trailers up or down steep grades.
