All I can really say is I have close friend and he works in Milwaukee. "wink"
I have had the list for a couple years now. So some may of changed.
But I do know Citgo is still making the oil products.
I have seen similar lists through the years at various web sites also.
I don't want to start a "Which oil is best" or get off topic with this.
But this is what I have run is all my bikes with no problems.
http://www.bradpennracing.com/Products/SAE20W50.htmlGood O American made oil. I use the racing oil not there motorcycle oil by the way.
If you look at the specs, the 20w50 racing oil has a higher HTHS. That's why I use it instead of the MC version. The HTHS of the 20w50 racing oil is 6.2, which is the highest HTHS vis of any 20w50 I've ever seen. It even bests Amsoil's 20w50 motor cycle oil which has a HTHS of 6.02. The HTHS for the Penn Grade 1 20w50 MC oil is 5.7.
HTHS = High-Temperature High-Shear
Low HTLS would give better efficiency or MPG. High HTLS gives more durability.