For 1950 Buicks, there is a specific 1950 Buick Lubricare program. The standard chart used in the automobile industry for specifying the SAE grade of oil to use with relation to temperature conditions is as follows:
Above 320 F.
As low as +10° F.
As low as -10° F.
Below -10° F.
It has been called to our attention that many people are interpreting the temperature to mean average temperature for the season rather than lowest anticipated temperature. The oil grade used should be that which is indicated for the minimum temperature under which the car might be required to make a cold start. The purpose in recommending the lighter grades of oil for colder weather is to provide easier starting and better lubrication during the warm-up period.
Reports indicate that many complaints of hard startings and a prolonged period of hydraulic valve lifter noise during warm-up, is due to using a grade of motor oil which is not really suitable for the particular operation.
Effective immediately, we are changing our oil grade recommendations to read as follows:
Temperatures SAE Grade
(Lowest anticipated, under which car is required to make a cold start)
Not lower than 32° F. 20-W
Not lower than plus 10° F. 10-W
Not lower than minus 10° F. 10-W
Below minus 10° F. 5-W (if available) or 10-W plus 10% Kerosene
This differs from our previous specifications in that 20-W is recommended for normal (above 32°F) operation and 10-W is specified for “not lower than plus 10° F.”