International Colloquium Tribology
ict
expert verlag Tübingen
125
2022
231
Axle lubricant composition impact on efficiency and work loss using light duty truck drive axle
125
2022
Arjun Goyal
Donna Mosher
ict2310145
23rd International Colloquium Tribology - January 2022 145 Axle lubricant composition impact on efficiency and work loss using light duty truck drive axle Arjun Goyal BASF Corporation, Florham Park, NJ, USA Corresponding author: arjun.goyal@basf.com Donna Mosher BASF Corporation, Florham Park, NJ, USA 1. Introduction Axle lubricant composition impact on axle efficiency and work loss was studied. The testing was performed on a light duty pick-up truck drive axle with lubricants of various compositions. The results of the study showed that the lubricant composition consisting of base oil type, additive technology, thickener (viscosity modifier) and finished fluid viscosity has significant effect on the average efficiency and work losses. The study evaluated several commercially available SAE J2360 approved lubricants as well as experimental formulations. The data show the thickener component had a significant impact to the results. These results will be used to improve further axle lubricant compositions to meet the United States Environmental Protection Agency’s (EPA) Green House Gas (GHG) regulations that improves fuel economy and reduces carbon pollution. A light-duty pickup truck axle of 235 mm rig gear diameter having axle ratio of 3.21: 1 was installed on a dynamometer at an independent lab. The tests were completed using United States Environmental Protection Agency (EPA) Green House Gas (GHG) testing protocol. The total work loss and average efficiency over the cycle was measured with various lubricants. The observations are summarized below. 1.1 Test Repeatability Efficiency and Total Work Loss using a commercial oil was re-run three times during the testing. The results did not significantly change during the study. The average efficiency and total work loss data is provided in Figure 1 below. Figure 1 Two oils were prepared using different SAE J2360 commercial additive packages having the same base oil and thickener. The data in Figure 2 below show that the additive package has minimal effect on work loss or efficiency in this axle design. 146 23rd International Colloquium Tribology - January 2022 Axle lubricant composition impact on efficiency and work loss using light duty truck drive axle Figure 2 1.2 Viscosity Effect The influence of finished fluid viscosity was studied. Oils were blended with different viscosity grades using the same additive and base oil. The viscosity was adjusted by the amount of thickener. All the oils tested are expected to meet SAE J2360 specification requirements. Work Loss and Average Efficiency, as shown in Figure 3 and 4, were significantly affected by varying fluid viscosity. Figure 3 The work loss continued to decrease with viscosity but started increasing above SAE 75W-80 viscosity grade. Similar observation (Figure 4) was seen with average efficiency. The efficiency continued to improve with decrease in viscosity but started increasing beyond SAE 75W-80 grade oil. Figure 4 From viscosity related work it, was observed that the optimal viscosity to get lowest work loss and improved efficiency is with a SAE 75W-80 viscosity grade (9.0 to 10.5 cSt @100°C). 1.3 Base Oil Effect For this study, oils were blends of similar viscosity using different base oil types. As shown in Figure 5 below, base oil type has significant effect on both work loss and efficiency. 23rd International Colloquium Tribology - January 2022 147 Axle lubricant composition impact on efficiency and work loss using light duty truck drive axle Figure 5 The results showed PAG base oil types performed best while Group II performed worst. 1.4 Thickener (Viscosity Modifier) Effect Several commercial and experimental thickener types were studied in same base oil and additive system. All the oils were SAE 75W-85 viscosity grade. The results are shown in Figure 6 below. Figure 6 It is shown that thickener (viscosity modifier) type has the most significant effect on the efficiency and work loss. This new knowledge is being used to generate highly efficient lubricants. 1.5 Conclusion The results of this study showed that base oil type, additive, thickener (viscosity modifier) and finished fluid viscosity have significant effect on the average efficiency and total work loss. Several commercial and experimental lubricants were evaluated in this study meet or are expected to meet the SAE J2360 specification requirements. The thickener type has significant influence on the efficiency. The study is being used to identify combinations of base oil and thickener types for a given viscosity grade to progress highly efficient lubricants needed to meet the US EPA GHG standards.
