Saab 1987 900 Owner's Manual page 34

32 Starting and driving
option is optimized to provide higher per-
formance on high octane fuel (premium
grade is recommended), however perfor-
mance will not be as good as the standard
model on lower octane fuel.
A control system, such as the APC system,
which is based upon a knock detector, can-
not eliminate individual occurrences of
knocking as these are necessary for the
function ofthe system. When the knock de-
tector "hears" engine knock the control unit
lowers the charge pressure in stages to the
point where knock does not occur. If the
same power demand (throttle position) is
maintaned the APC system increases pres-
sure until knock once again occurs. The
knock detector will again "hear" the knock
and the cycle will be repeated. The system
thereby constantly searches for the op-
timum charge pressure for the combina-
tion of engine speed, load and knock level.
Proper driving habits and care
Starting
Do idle the engine at least ten seconds after
start up to ensure full oil pressure at the tur-
bocharger before engine speed is increased,
especially in colder weather.
Don't rev the engine immediately after star-
ting or permanent damage to the turboc-
harger will result.
Don't use full throttle while driving until a
cold engine has warmed up for 2 or 3 minu-
tes or until the temperature gauge needle
has entered the green zone.
Stopping
Let the engine idle 20-30 seconds before
switching it off after driving to allow time
for the turbocharger to coast down from
high rpm before oil pressure at the bearing
is depleted. For the same reason, don't rev
tIle engine immediately before switching it
off. Permanent turbocharger damage will
result. After hard driving let the engine idle
about a minute to let the oil cool the turboc-
harger bearing somewhat. This will also
help prevent breakdown ofthe oil.
Follow the recommended maintenance
schedule. In particular be sure to:
• Check the engine and transmission oil
levels frequently .
• Change the engine oil and filter at least
every 3,750 miles or 6 months. Use only
oils which meet specifications given in
this manual. Oil additives are not recom-
mended.
• Follow the coolant recommendations
(don't use plain water) and change it
regularly.
• Take your Turbo to a Saab dealer if you
notice a loss of power, an increase in oil
consumption, heavy engine detonation
while accelerating or driving at high spe-
ed, or abnormal temperature or boost
indications. Do not run the engine wit-
hout the standard air cleaner and
exhaust system in place. Do not tamper
with the turbocharging, APC or emission
control systems.
Gear selector lever
Manual Transmission
The gear positions are shown on the gear
lev~r
knob. Fifth gear is the highway gear in
whIch best fuel economy can be achieved.
To engage reverse (R) , first raise the collar
on the gear lever.
NOTE! Reverse gear is not synchronized.
Engage reverse only when the vehicle is
completely stopped and only with the
clutch pedal fully depressed and the
accelerator fully released. When parking,
apply the hand brake after engaging
reverse gear.