why was 10W-40 so popular back in the 1960's?

[A_Harman]

Thanks for the table, Quattro Pete. I thought I saw somewhere that the limit for low temperature pumping viscosity had been lowered to 40,000. Has anybody else seen that?

 

[Garak]

Originally Posted By: Boxnuts
Curious choice of table to illustrate your point. KV40 figures do appear in 3 columns to KV100 in two columns. Anyway this seems to be an old J300 table, the CCS and Pumping figures are now quite different.

Dag nabbit! I did see other more recent tables, but when writing my reply, I wanted to grab a small one and post it in a non-intrusive fashion, and did so without looking closely. I guess it was far more intrusive than I could have possibly imagined.

Thanks to Quattro Pete for posting a much more recent example and helping extract my foot from my mouth. I'm afraid to go back and try to determine how old the table I referenced was.

 

[supercity]

Originally Posted By: Shannow

20W-50 was the staple everywhere. GTX, XLD,
Shell were strange with Super SF 20W-40, and XMO (15W-30...wish that gradewas still around)
BP had Corse, 25W-50.
Duckhams had 15W-50, which was green, and odd.
M1 was 15W-50.

Each manufacturer made limited offerings, not many 15W-40s were plain petrol rated.

Then late 80s, they all went stupid.
STP, and Penrite started their 20W-70 stories, BP Corse went 25W-60, people started with 80s etc.


I remember 20w40 and also "30/40"