Re: What kind of oil to use? 1941 Packard 110

Posted by DrewLA On 2015/5/16 0:53:26

There are many posts on this site already discussing various brands and viscosity grades of oils, which I highly recommend reading, but here are some of the key takeaways:

-Detergent oil wasn't commercially available when the owners manual was printed, but has been used successfully for many miles by folks on this forum. Detergent oils help prevent and dissolve sludge
-Multi-weight (e.g., 10W-30) engine oil didn't exist when the owners manual was printed but is a better choice than a single weight oil if you have any real variation between low and high temperatures between day and night
-There have been significant advances in engine oil technology since that time
-A 10W-30 would be fine for this engine if daytime temperatures don't regularly get above 90 degrees F, otherwise a 10W-40 or 15W-40 is a good choice.
-Mixed fleet diesel/gasoline oils (I.e., those which are primarily meant for diesel vehicles but which also carry an API SL, SM, or SN rating) are an excellent choice because they have the levels of ZDDP some people feel is necessary in these old cars.
-Shell Rotella T Triple Protection, Mobil Delvac, and Chevron Delo are all widely available, well-respected brands, which offer oils in this space.