Shell Rotella Unveils Next-Gen API CL-4 and FB-4 Oils

Shell Rotella’s upgraded API CL-4 and FB-4 heavy-duty engine oil lineup brings enhanced deposit control and extended warranty coverage to commercial fleet operators.

Shell Rotella has introduced its next-generation heavy-duty engine oil portfolio engineered to meet the upcoming API CL-4 and API FB-4 specifications. Replacing the current API CK-4 and FA-4 categories on the January 1, 2027 licensing date, the new formulations are designed to handle higher operating temperatures and protect modern emissions aftertreatment systems, including diesel particulate filters (DPFs) and selective catalytic reduction (SCR) units.

For motor carriers and fleet maintenance managers, the API CL-4 category offers full backward compatibility, enabling standardized lubricant sourcing across mixed-age diesel equipment. Performance testing shows Shell Rotella T4 15W-40 achieves 58% stronger deposit control compared to legacy CK-4 formulations, while the T5 10W-30 synthetic blend exceeds oil breakdown resistance requirements by over 90%. Additionally, the T6 10W-30 full synthetic delivers 66% greater wear protection than required under baseline CL-4 metrics.