LOW VISCOSITY ENGINE OILS: FUEL ECONOMY AND PERFORMANCE IN A REAL-WORLD FLEET TEST

Abstract

CO2 emissions and fuel consumption reduction in road transportation have become one of the most relevant concerns in automotive industry, led mainly by global warming. A variety of solutions has arisen to overcome this challenge, varying in technical complexity, implementation costs and terms. Among them, one proven cost-effective way to reduce fuel consumption is the use of low viscosity oils (LVO). There are different studies involving LVO and ICE, but currently limited data are available regarding “real-world” performance of LVO. This paper presents a study where the effect of the use of LVO on urban buses regarding fuel consumption and oil performance is assessed. A comparative analysis using 39 buses was performed, based on an extensive fuel consumption control and oil analysis program to assess aspects aforementioned. 2 engine technologies (Diesel / CNG) were considered and 4 different lubricants. Test duration comprised 2 oil drain intervals, totalizing more than 2 million of km accumulated. The results have shown that LVO have benefits in terms of fuel economy, closely linked to the engine design. On the other hand, they presented an excellent performance during oil drain interval, even improving some characteristics of the reference oils used, without penalty in terms of reducing the oil lifespan, a key indicator for end users related maintenance costs. Keywords: Lubrication, ICE, Low viscosity oils, fuel economy, engine wear