The growing importance of additives in motor oils

With the launch of ILSAC GF-7 motor oils earlier this year, additive chemistry plays an important role in meeting the category’s more stringent requirements for wear protection, fuel economy, and emissions system compatibility. Additives, the hidden workhorses of engine oil performance, have been re-engineered to meet evolving OEM demands while supporting engine durability under increasingly harsh operating conditions.

Engineered for Modern Engine Requirements

ILSAC GF-7 builds on the foundation set by GF-6 by tightening limits on wear, oxidation, and deposit control, while also enhancing protection for turbocharged, gasoline direct injection (GDI) engines from Low Speed Pre-Ignition (LSPI).  As a result, formulators have leaned heavily on next-generation additive packages to deliver results in several critical areas:

• Friction modifiers are optimized to improve fuel economy without compromising wear protection. These components form low-friction films that reduce drag between moving engine parts, contributing directly to GF-7’s fuel efficiency targets.
• Oxidation inhibitors have been upgraded to extend oil life and slow down oil degradation at high temperatures, a growing concern in modern downsized engines that run hotter than their predecessors.
• Detergent and dispersant systems offer improved cleanliness and deposit control, particularly around piston rings and turbocharger components. Additive packages featuring higher levels of magnesium and reduced calcium content have shown strong results in mitigating harmful buildup while supporting LSPI resistance.
• Viscosity modifiers play a key role in GF-7 oils, enabling wide-temperature performance and improved shear stability for longer in lower-viscosity motor oils like SAE 0W-16 and 0W-20, which are now required by some OEMs.
• Emission system compatibility is also a focal point. Additive packages now have lower limits on heavy metals that contribute to ash content, minimizing the risk of catalyst poisoning and aligning with tightened GF-7 emission requirements.

LSPI Mitigation

Low-Speed Pre-Ignition (LSPI) remains a concern, particularly for turbocharged GDI applications. Additive formulators continue to include LSPI-mitigation chemistry as part of the overall chemistry design, leveraging molybdenum-based friction modifiers, antiwear agent and detergent/dispersant combinations to reduce the risk of engine damage.

Looking Forward

As engines continue to advance and motor oil specifications change, additive innovation will remain essential, not only for meeting specification limits but also for differentiating performance in the marketplace. Whether extending the life of emission systems, protecting against wear in turbocharged engines, or preserving fuel economy in ultra-low-viscosity formulations, additive technologies are the cornerstone of modern motor oil development.

Sean Nguyen is a Pennzoil technical scientist and automotive lubricant specialist

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