TOP TIER™ Revises Deposit Control Standard
With the evolution of engine technology, gasoline direct injection (GDI) represented 73% of new vehicles sold in the US, according to the 2024 EPA Automotive Trends Report. This method of injecting fuel directly into the cylinder helps original equipment manufacturers (OEMs) meet stricter CO2 emissions and fuel economy standards.
Twenty years ago, a group of OEMs established the voluntary TOP TIER™ standard to enhance detergency for optimal engine performance. Recognizing the need for an update, they have now introduced the revised TOP TIER+™ standard.
The new TOP TIER+™ standard includes additional requirements to address potential deposit issues in GDI engines. Using a GM LHU engine, two new test requirements have been developed. The first test evaluates injector deposit control by measuring injector fouling and particulate emissions, as injector deposits can lead to poor spray patterns, compromised fuel delivery, reduced fuel economy, and increased particulate emissions. The second test focuses on protection against stochastic pre-ignition (SPI), a harmful pre-ignition event that can occur in modern downsized engines and potentially lead to engine failure.
Published in early January, this revised standard gives fuel marketers two years to comply with the new TOP TIER+™ requirements. In anticipation of these changes, we have developed a new series of deposit control additives specifically designed for GDI engines. Afton's HiTEC® 65522 Gasoline Performance Additive (GPA) series is formulated to maintain excellent control of intake valve deposits while providing enhanced deposit control for direct injection engine technology. For more information about the benefits of HiTEC® 65522 GPA series, please contact your Afton representative.