Engine lubrication in the global automotive industry has many challenges in the world today. One of them is the pursuit of fuel economy which has resulted in the growing popularity of lower viscosity engine oils. However, engine wear protection of low viscosity oils is not as robust as for higher viscosity grade oils. Due to this, low viscosity grade engine oils, such as SAE 0W-20, are not common in tropical climates, though they could provide the added benefit for fuel economy. To address these two seemingly discordant performance characteristics, PTT has developed a new API SN, SAE 0W-20 engine oil with a novel viscosity modifier and conducted a field trial with extended oil drain intervals to gain a better understanding of its performance in tropical climates, especially its wear protection performance in passenger cars.Results from the field trial showed that the new novel viscosity modifier was able to maintain excellent shear stability compared to the reference oil throughout both phases of tests. On top of this, the candidate oil matched the reference oils' fuel economy while maintaining a higher kinematic viscosity. Engine inspections also showed comparable performance in sludge and wear; as well as excellent performance over the reference oil in deposits control. The data from this exercise showed the candidate formulation to be suitable for use in tropical climates and was able to provide excellent wear and deposits control under long drain interval conditions.