Description Shell 550046214 Rotella T5 15W-40 Diesel Engine Oil is formulated and designed to energize the diesel engine oil's performance and provides fuel economy benefits, improved low-temperature flow, and delivers an advanced "Low-SAPS" formulation which helps control the blocking or poisoning of exhaust after-treatment devices. The combination of semi-synthetic oils and advanced additive system delivers excellent protection, even at low temperatures where the enhanced cold-flow properties help protect your engine. The SAE 15W-40 synthetic oil has API CJ-4 additive technology that is compatible with the latest exhaust-emissions control systems.