Yes, I had the same experience when looking for Rotella T6 5w-40 a few weeks ago myself. Even less selection at Sam’s Club.
I never did find it, but there is a full synthetic T6 15w-40 that meets the FORD WSS-M2C171-F1 spec, and at least around my area is more available. Personally, I’d rather use a full-syn 15w-40 than a conventional or syn-blend 10w-30, which is the “regular service” oil recommended for the 6.7. I don’t experience the extreme low temps in my area that you may in yours.
If you’re wanting to stick with an approved 5w-40 oil, all of the oils of that type listed on this sheet meet the Ford spec.
DIESEL MOTOR OILS MEETING FORD WSS-M2C171-F1:):)
:R Let’s Go Girls!
😛NRA Benefactor Life Member
Lance 1121-Two Awnings, Slide topper, 3.6 kw Gen, Trimetric Batt. Monitor, 1500W Inverter, 40A Redarc DC-DC charger. 2016 F450 6.7 PSD.
2001 Lance 1121 on a 2016 F450 ‘Scuse me while I whinge.
And for all you Scooby-Doo and Yosemite Sam types………..Let’s Go Brandon!!!