Whats is the difference between these Castrol 5W30 Edge oils?

[aquariuscsm]

Specifically the "Castrol Edge 5W30 U.S." from 20 Apr 2021 and the "Castrol Edge 5W30 K" from 17 Nov 2021? They have a high temperature viscosity difference according to the pds.

Castrol - PDS & MSDS Search

The MSDS/PDS tool aims to provide the users access to material safety and product data sheets and satisfy Castrol's legal requirement to publish.

msdspds.castrol.com

 

[blufeb95]

Edge US is a Dexos/ILSAC/ACEA C2 oil, the K is ACEA C3 so it's thicker and has a minimum HTHS of 3.5

 

[SR5]

I use a lot of the Edge 5W30 A3/B4 myself. It's also MB 229.5 and BMW LL-01.