Monolec Ultra Syn Heavy Duty Engine Oil pays for itself with all-weather performance, wear protection and fuel economy. This broad-range multiviscosity synthetic oil for diesel engines delivers outstanding year-round performance, wear protection, fuel efficiency and extended drains. With its synthetic base oil and exclusive additive package, this 5W-40 formulation reliably lubricates diesel engines, even in low-temperature conditions, without the shear stability and viscosity problems of conventional diesel engine oils. Its high viscosity index indicates less change in viscosity over a broad operating temperature range.
One of the primary advantages of 5W-40 vs. 15W-40 engine oil is better fuel economy. In a controlled lab setting, GM 6.5L dyno testing showed a 1.5-1.6 percent fuel economy improvement. In addition, broad-range oils are preferred for low-temperature conditions because of their ability to achieve flow quickly during cold startups. Most engine wear occurs within the first two to five minutes of starting. However, conventional low-viscosity oils have not always provided adequate oil film at operating temperatures. This resulted in increased wear and made it difficult to obtain OEM approvals. The improved technology of Monolec Ultra Syn has eliminated this problem, enabling it to achieve flow quickly in cold weather and maintain viscosity. It also meets all major OEM approvals. Monolec Ultra Syn Heavy Duty Engine Oil lubricates important parts faster, prevents wear during operation, and decreases fuel consumption – making it the smart choice for on- and off-road fleet managers and owner operators who want better fuel economy, reliable low-temperature performance, or a combination of both.