1938 LaSalle Production - GM Heritage Center

Right Gasoline
Right Engine Oil
The Cadillac V-8 engines provide all the benefits of
modern high-compression design, which means that they
operate most efficiently with ethylized or other high-octane
fuel. The series 38-75 engine has a particularly high compression
ratio, and it accordingly requires a premium grade
fuel, such as "Ethyl" gasoline.
The series 38-60 and 65 engines are so designed and calibrated
that they will perform satisfactorily with 70-octane
fuel, which is the rating of the so-called "regular" grade of
gasoline marketed by most refiners in the United States.
Premium fuels having octane ratings well above 70, if used
with an advanced spark setting, will permit these engines
to develop more power.
Fuels with octane ratings less than those recommended
above can be used without harm, but they will not permit
the engines to develop their full power, and they will usually
cause "knock" or "ping" unless the spark is retarded. Ignition
timing and "ping" are explained on page 46.
The most important thing is to buy your fuel from a
reputable company in order to insure uniform quality and
freedom from impurities that might clog the strainers or
cause harmful chemical action in the engine. Your Authorized
Cadillac-LaSaile Service Station can advise you regarding
the most suitable grades of gasoline available locally, or
adjust your engine for the grade of fuel you prefer to use.
The gasoline tank capacities are:
Series 38-60
Series 38-65 and 75
Page 6
22 gallons
26 gallons
During the first 1,000 miles, the lighter grades of
engine oil must be used. When it is necessary to add oil use
nothing heavier than 10W in winter or 20W in summer.
At the end of 1,000 miles, the oil originally in the
engine should be drained and replaced with oil of the correct
grade. The grade depends upon the season of the year and
the type of driving, as explained on pages 37 and 38.
In checking the engine oil level between oil changes,
there is only one safe rule: Check the oil level every time
gasoline is purchased and add oil as required. Oil will
not be required every time, but it is better to check the level
unnecessarily a dozen times than to miss the one time that
more oil is needed.
The combination oil filler cap and plunger type gauge is
Page 7
on the left side of the
crankcase.*
Add oil
whenever the level is
down to the 6 quart
mark but add only
enough to bring the
level up to the 7-quart
mark.
*Raising the hood is explained
on page 8.