High Mileage Driving - Pontiac 1953 Owners Service Manual

the crankcase from condensation of moisture. Under these con-
ditions, it may be advisable to change oil at 1,000 mile intervals.
High Mileage Driving-For the exceptional person who is oper-
ating his car 500 "to 1,000 miles per week and using premium or
heavy duty oils, consideration may be given to greater mileage
between oil changes. On continuous high·speed driving, oils have a
tendency to thicken . This should be kept 'in mind when preparing
COl;S
for cold weather driving.
Year-to·year improvements that have been made in the Pontiac
lubricating system such as the built·in Pontiac Oil Cleaner and the
improved crankcase ventilating system have extended the period
over which lubricating oils may be used. In order to protect the
working parts of the engine and prolong engine life, engine oil
should be changed whenever it becomes contaminated. This will
insure continuation of the best performance with low maintenance
cost. Contamination is usually due to the accumulation of water,
dust or dirt, or the breakdown products of the oil itself. Outside of
making a laboratory test, it is practically impossible for anyone to
tell the amount of contamination in an oil by either looking at it or
feeling it. Experience has shown that the degree of contamination
is largely dependent on the conditions under which a car is operated,
and, accordingly such conditions must be taken into consideration
in deciding when to change oil.
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