Panic
All your car engines seam to be in reasonably good condition if sae 30 makes then turn difficult when cold.
The bearings of older engines are mostly near or over their limits so oil has plenty of space and that results in less friction.
I am considering to use 15W40 for in the summer and 10w30 for winder unless I find a supplier of W20 or sae20 here in the Netherlands
Jianis
