User Manual

DDEC IV ENGINE DRIVING TIPS
If you decide to drive at lower rpm 's
for improved fuel economy, don't let
different engine noises t hro w you
off guard. The Series 50 sounds
quiet at 1400 rpm, almost as if it
had quit p ulling. D on't believe it!
If you had a boost gage to look at
while driving, you would notice
the turbocharger maintaining steady
intake manifold pressure, even as
rpm's fall. Depending on the air
intake arrangement, you may also
experience a “chuffing” sound as the
engine starts to pull hard at lower
rpm's. This is caused by the velocity
changes of the air flow wi thi n the air
intake plumbing. Electronic engines
can actually deliver more fuel at lower
engine speeds than at rated speed.
Idling
The common belief that idling a diesel
engine causes no engine damage is
wrong. Idling produces sulfuric acid,
which breaks down the oil and eats
into bearings, rings, valve stems and
engine surfaces. If you must idle the
engine for cab heat or cooling, the
high idle function of the cruise control
switches should be used. An idle
speed of 1100 rpm should be enough
to provide cab heat in above 32° F (0
°C) ambients.
Winter Fronts
Awinterfrontmaybeusedtoimprove
cab heating while idling, but it should
never co ver more than 3/4 of the
grille while driving. Winter fronts
should only be used when the ambient
temperature rem ains below 10° F
(-12.2 °C).
40 All information subject to change without notice. (Rev. 01/04)
DDC-SVC-MAN-0058 Copyright © 2004 DETROIT DIESEL CORPORATION