F+L Week 2019 | Zheng Qin | Balancing durability and catalyst compatibility for future motorcycle engine oil applications
Stringent global fuel economy standards and emission regulations are driving motorcycle hardware upgrades. The use of fuel injection systems and advanced after-treatment devices are gaining popularity in motorcycle hardware design and these changes significantly impact the requirements of motorcycle lubricants. Unlike passenger car oils that only lubricate an engine, motorcycle oils must lubricate both the engine and the drivetrain. The drivetrain includes highly-loaded gears that are exposed to high pressures and requires lubricating oils with high film strength and specific anti-wear componentry for durability. Typically, phosphorus-containing additives (primarily ZDDPs) are used to provide anti-wear protection as these additives have been well studied and utilized in nearly all lubricant applications for many decades. The growing emphasis on reduced emissions for motorcycles (and all internal combustion vehicles) has forced an evaluation of both the treat rates and types of phosphorus-containing additives used in lubricants due to the deleterious effect phosphorus has on conventional three-way catalyst (TWC) performance. To minimize the impact on TWC performance, Lubrizol introduced a low-volatility HyperZDDPTM anti-wear system that provides excellent durability with prolonged catalyst life. In anticipation of future specifications, Lubrizol has also developed motorcycle oils in lighter fuel-economy viscosity grades and at lower phosphorus levels than permitted in current specifications, without compromising the gear protection performance. These low-phosphorus, low-viscosity formulations maximize both fuel efficiency and catalyst lifetimes with a view to next generation hardware lubricant requirements.