Synthetic transmission oil for heavy-duty vehicles
To meet the Paris Agreement’s climate goals, commercial vehicles need to reduce emissions by 80% by 2050. The European Union has set CO2 reduction targets of 15% by 2025 and 30% by 2030 for commercial vehicles. To reach these goals, heavy-duty transmission fluids are moving toward lower viscosity – currently 10-14 cSt kinematic viscosity (KV) @ 100°C but trending lower – while striving to maintain, and even improve, wear protection and durability.
Achieving these lubrication goals is especially difficult for heavy-duty vehicles, which must cope with higher shear, higher temperatures and higher wear compared to passenger vehicles. Increasing drain intervals from 300-500K KM to the target goal of 1M KM requires innovative formulations.
Low temperature performance
Shear stability is taking on greater importance because of increased use of wide-span multigrade lubricants to improve fuel economy and service life. Because automotive gear lubricants typically contain viscosity modifiers that can shear in service, reducing viscosity and potentially leading to increased wear, stay-in-grade performance is part of the SAE J306 standard.
The three fully synthetic formulations in this chart do not contain polymers, but the high molecular weight PAO can suffer from shear. We can see that all three blends are very shear stable, remaining within the SAE 75W-90 spec even at extended test hours. These results demonstrate long lubricant life.