Quaker State conventional/synthetic blend motor oil maintains viscosity grade from start to finish to give your engine optimal protection, while also providing corrosion protection against harmful acids generated by engine contaminants.
Quaker State puts its motor oil to the test in real-world conditions in taxi fleets across North America, ensuring it will deliver tough, reliable performance over the distance — from excessive idling time to the constant accelerations and decelerations of heavy traffic.
Quaker State heavy duty SAE 30 motor oils are formulated to deliver consistent wear and viscosity protection throughout the life of the oil. Independent laboratory tests show that heavy duty motor oils beat industry wear standard with three times better wear protection. The used oil (standard oil drain, for the vehicle), also passed the industry standard. Today's vehicles and their busy drivers need today's heavy duty motor oil. API SN certified.