Here's the Discontinued oil.
https://cglapps.chevron.com/sdspds/PDSDetailPage.aspx?docDataId=481951&docFormat=PDF
- Viscosity, Cold Crank, °C/mPa.s -20/5400
- Pour Point -45F
- Delo® 400 SDE SAE 15W-40 is approved for:•
- API Service Categories CK-4, CJ-4, CI-4 PLUS,CI-4, CH-4, SN•
- Cummins CES 20086•
- Daimler MB-Approval 228.31•
- Detroit Fluids Specification (DFS) 93K222•
- DEUTZ DQC III-18 LA•
- MAN M3775•
- Mack EOS-4.5•
- MTU Category 2.1•
- Renault RLD-3•
- Volvo VDS-4.5
- Delo 400 SDE SAE 15W-40 meets the requirements for:•
- ACEA E9, E11•
- Caterpillar ECF-3•
- JASO DH-2•
- MAN M3575
Here's the new replacement.
https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=481952&docFormat=PDF
- Viscosity, Cold Crank, °C/mPa.s -20/5200
- Pour Point -38F
- Delo 400 XLE SB SAE 15W-40 is approved for:•
- API Service Categories CK-4, CJ-4, CI-4 PLUS,CI-4, CH-4, SN•
- Cummins CES 20086•
- Detroit Fluids Specification (DFS) 93K222•
- Mack EOS-4.5•
- Renault RLD-3•
- Volvo VDS-4.5
- Delo 400 XLE SB SAE 15W-40 is recommended for:•
- ACEA E11•
- Allison TES-439•
- Caterpillar ECF-3•
- DEUTZ DQC III-18 LA•
- DTFR 15C100 (previously known as MB 228.31)•
- Ford WSS-M2C171-F1•
- JASO DH-2•
- MAN M3775•
- MTU Category 2.1
They received more "Approvals" & IMO a beefier additive pack like Phosphorus to meet Ford Spec on this newest product. The Cold Crank test seems to, slightly, favor the old 15w-40 (Synblend) product mentioned below. Apparently it was already a synthetic blend before. You can see (Synblend) in the title before naming it SB.
Then there's this product you're referring to 15w-40 SDE (Synblend) that has that low -54F pour point. Product number 257004. This must of been the product you're talking about & it appears it was launched around the time of CK-4.
https://shop.sclubricants.com/pub/media/pds/chevron/Delo-400-XLE-SAE-15W-40-Technical-Datasheet.pdf