Emissions regulations have driven the quality levels of heavy-duty diesel engine oils over the past several years because they are required to protect aftertreatment devices as well as meet the high demands of OEMs and their customers. Matt Bentley, Product Manager, Commercial Engine Oils and Denis Gryazev, OEM Account Manager, Off Highway at The Lubrizol Corporation, note the role of a lubricant has become very broad. In addition to protecting aftertreatment systems, lubricants are also expected to provide efficiency gains and durability.