Winter & Summer

[65RRR]

Hi Bob, I'm new here too. I build Mac trucks at a plant in Macungie, PA. My question is, if I change over on my 65 Vette to synthetic, do I have to change the weight in the summer? I usually use a heavier weight in the summer and lighter in the winter. What would you recommend, and should I be changing weights for seasons with the regular oil? I'm asking this because it's been the old rule of thumb, but how true is it? :wave:

[Robert Pache]

Actually, unless you drive very short distances, operating oil temperature is not significantly different between summer and winter. The multigrade oils such as 5W-30 or 10W-30 provide faster oil flow and quicker startup revs in the winter to reduce startup wear and battery drain. However, in the summer, these oils flow faster on startup. Remember, it is estimated that 85% or more of the engine wear occurs at startup. I would use 10W-30 all year around.

Bob

[65RRR]

Thank you for taking the time. Hope to meet you at one of the car shows.:wave: