SALB,  Rotella products are good for motorcycles and carry the JASO motorcycle rating right on the jug.

Delo 400, can't give a recommendation on that one.  Never used it or oil warred it before.   Can't say what special friction tweeks may be inside it, but I can say it isn't motorcycle wet clutch rated on the jug.   In general, diesel oils are pretty good for the Savage, but you are mentioning "special additives" that we know nothing about ...

Heroicseven, you have "an unknown spec" 20W50 Castrol GTX right now as you didn't read the jug closely and have likely thrown the jug away by now.   Run it until the next oil change time and pay better attention to what you are buying next time.  

General use American Castrol GTX isn't recommended by Castrol for flat tappet engines like the Savage .... they acknowledge the lack of ZDDP for flat tappet use.   Next, American Castrol GTX isn't rated for motorcycle wet clutch use (no JASO markings on the jug) so exactly what the heck motorcycle site was recommending it again?  

* THIS DATA SHEET DOES NOT CONSTITUTE A CONTRACT IN TERMS OF PROPERTIES

When Castrol puts this at the bottom of their spec sheets it means the stuff can change from local to local and what you just got shipped in from Podunk may not actually meet the specs given by this data sheet.  

And then when you see the same brand name being used internationally to represent oils that are COMPLETELY DIFFERENT, well then you gotta figure you may be running a little bit of "spec risks" if you use Castrol without reading the jug very very carefully.

ha ha just joking around a bit, but seriously thank you. I will be swapping for something more accommodating of our engines tomorrow.



April first has a long history of joking around a bit here on the list, so "April Fool" right back at you.