Shell Rotella T5 synthetic blend heavy-duty engine oil combines synthetic blend base oils and advanced additives to deliver excellent protection, even at low temperatures where the enhanced cold-flow properties help protect your engine. Shell Rotella T5 is formulated and designed to energize the oil's performance and provides fuel economy benefits, improves low-temperature flow and delivers an advanced "low-saps" formulation which helps control the blocking or poisoning of exhaust after-treatment devices.