fuel additives SAAB 9-5 2003 Owners Manual

159 Starting and driving
Opening the fuel filler door in an emergency,
see page 150.
Recommended fuel:The engine in your Saab 9-5 is designed to
operate on unleaded gasoline that has an
octane rating of 87 or higher. Octane rating
is determined according to the formula:
where MON is the Motor Octane Number,
and RON is the Research Octane Number.
The average of these two values is the
octane rating of the gasoline as it appears
on the pump at a retail gas station. This
value is sometimes referred to as the
"Anti-Knock Index" (AKI) or the "Average
Octane Number" (AON).
To avoid deposit formation on the fuel injec-
tors which can cause poor driveability, use
only quality gasolines that contain deter-
gents and corrosion inhibitors. Because
gasolines sold at retail gas stations vary in
their composition and quality, you should
switch to a different brand if you begin expe-
riencing driveability and/or hard starting
problems shortly after refueling your car. In
recent years, a variety of fuel additives and
alcohols or oxygenates have been blended
with gasoline. These types of gasolines may
be found in all parts of the United States and
Canada, but particularly in geographic
areas and cities that have high carbon mon-
oxide levels. Saab approves the use of such
"reformulated" gasolines in its products,
which help in reducing pollution from all
motor vehicles, provided that the following blending percentages are met by such
fuels:
 Up to 10 % ethanol by volume, with corro-
sion inhibitors.
 Up to 15 % MTBE by volume (methyl ter-
tiary butyl ether).
 Up to 5 % methanol by volume, with an
equal amount of a suitable co-solvent and
added corrosion inhibitors.
Other, less common, fuel additives used by
some gasoline dealers are also acceptable,
provided that the resultant gasoline is not
more than 2.7 % oxygen by weight.
Some Canadian and U.S. gasolines contain
an octane enhancing additive called meth-
lycyclopentadienyl manganese tricarbonyl
(MMT). If such fuel is used, your emission
control system performance may deterio-
rate and the malfunction indicator lamp on
your instrument panel may turn on. If this
occurs, return to your authorized Saab
dealer for service.
However, these blended gasolines are reg-
ulated and should never exceed these rec-
ommended blend percentages and service
station operators should know if their gaso-
lines contain detergents and oxygenates,
and have been reformulated to reduce vehi-
cle emissions. Nevertheless, if you begin to
notice a problem with the way your car starts
or runs shortly after it has been refueled, try
a different brand of gasoline.
NOTICE Fill to maximum filling capacity
 Stop filling after the first time that the
nozzle trips to shut off the flow of fuel.
 Filling capacity can differ between
different fuel stations and outside
temperature. Fuel tank volume when
nozzle trips to shut off, may vary by
0.5 gal. (2 liters).
 Do not fill fuel all the way up the filler
pipe. The gasoline must be allowed
room for expansion especially during
hot weather.
MON + RON
2
ProCarManuals.com

179 Starting and driving
 Driving in a low gear results in higher fuel
consumption than in a high gear because
of the higher engine speed for a given
road speed. Always change up to a higher
gear as soon as traffic conditions allow
and use the highest gear as much as pos-
sible.
 Check the air pressure in the tires once a
month. Incorrect pressures increase tire
wear. It is better to have slightly higher
pressure than lower.
 Check fuel consumption regularly.
Increased consumption can indicate that
something is wrong and that the car
needs to be checked by an authorized
Saab dealer.
Practical trials on the roads have demon-
strated that substantial savings in fuel con-
sumption can be made if the above advice
is heeded.Road conditions Wet roads increase fuel consumption, as do
unpaved roads and driving in hilly country
(the amount of fuel saved driving downhill is
less than the additional amount required to
climb the hill).
Engine block heater (standard
equipment in Canada, accessory in
U.S.)The following are just some of the benefits
to the car and the environment of using an
engine block heater:
 Lower fuel consumption.
 Exhaust emissions substantially reduced
over short runs.
 Reduced wear on the engine.
 Inside of car warms up faster.
The engine heater is effective at outside
temperatures up to +15–20°C. The warmer
it is outside, the shorter the time the engine
heater needs to be connected. Longer than
1.5 hours is unnecessary.
If the car is equipped with a removable,
electrical cabin heater that is not in use, this
should be stored in the luggage compart-
ment.
Driving in cold weatherBefore starting a journey in cold weather
you should check the following:
 That the wiper blades have not become
frozen to the windshield/glass.
 Brush any snow away from the air intake
for the heater system (opening between
hood and windshield).
 It may be advisable to lubricate the
door-lock cylinder (use molybdenum
disulphide, MoS
2) to prevent its freezing.
If the lock has frozen, take care not to
break the key (or use the remote control)
– heat it first or spray it with de-icer.
 Periodically during the winter, add gaso-
line anti-freeze to the fuel to dispel any
condensation in the fuel tank which could
freeze and cause problems in the system.
Keep the tank well filled to reduce the risk
of condensation forming.
If the car is parked outside in freezing
weather, fuel additives (gasoline
anti-freeze) will not do any good as it
cannot remove water that has already fro-
zen. Park the car in a warm place so that
any ice that may have built up melts, then
add gasoline anti-freeze when filling up
the tank. Condensation is caused by
changes in the outdoor temperature or by
the car being parked alternately in a
garage and outside.
 It is particularly important when the roads
are slippery that the brakes and tires be in
good condition.
WARNING
Never switch the engine off while driving
as the effect of the brakes and power
steering will be greatly reduced.
ProCarManuals.com