Plymouth Gran Fury 1980 Operating Instructions And Product Information page 52

Scheduled Maintenance
Vehicles Used for High Performance Service
If the vehicle is to be used for maximum performance service
(very high speeds or very rapid acceleration), the engine req uires
heavier than normal lubricating oil.
For best protection of the engine, the h eav iest available engine oil
of SE or SF quality should be used that will permit satisfactory
cold starting. SAE 30 and SAE 40 are recommended; multi-
viscosity oils SAE 20W-40 and 20W-50 may also be used.
Additional engine protection can be gained through the use of
certain add itives. Hi-Performance Oil Additive (Sulfu rized Es-
ter) PIN 4106790, is especially useful in preventing piston pin and
skirt scuffing. H owever, this additive should not be used at
ambient tempertures below -10°F ( -23°C), nor should it be
added to the factory fill engine oil. Engine Oil Supplement
PIN
3419130 or4-188 provides additional wear and scuff protection for
valve train components.
When outside temperatures are con sistently below +32°F (0°C),
SAE 10W-30 or SAE 10W-40 is recommended for ease in cold
starting. However, even in cold weather these grades should not
be used if the vehicle is driven in competition or other forms of
50 maximum performance operation.
Oil Filter (Schedule A & B)
Particles of dirt or foreign matter that might enter the engine oil
are removed by a full-flow throwaway oil filter. The oil filter
should be replaced with a new filter a t the first engine oil change
and every second oil change thereafter or every 12 months,
whichever comes first. Severe operating co nditions require more
frequent filter changes.
Oil Filter Selection
All Chrysler Corporation engines are equipped with short type,
full-flow throwaway oil filters. This short type filter is recom-
mended as a replacement filter in service on all vehicles.
The quality of replacement filters varies considerably. Only high
quality filters should be used to assure most efficient service.
Mopar Engine Oil Filters PiN 3549957 or L-19 (short type) and PIN
1851658 or L-72 (long type) are high quality filters and are recom-
mended.
Carburetor Choke Shaft (Schedule A & B)
To prevent the choke sticking from gum deposits on the shaft,
apply the recommended solvent (available at your dealer) onto
the choke shaft where it passes through the air horn . Move the
choke blade back and forth to distribute the solvent.