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In line with Global targets of reducing CO2 Emissions, transportation industry is witnessing a significant shift in focus — from emissions to fuel economy — by regulators, researchers, OEMs, fuels and lubricant manufactures. Improvements in fuel economy can have a significant bottom-line impact for fleets and owner operators alike. There are many paths to take when looking at a program to reduce fuel consumption. These include new engine and transmission designs, new metallurgies, surface finish, coatings, new injection technologies, turbochargers and of course through engine and transmission lubricants. Passenger car engine lubricants are being upgraded time to time and customized for fuel economy and emission compliance benefits as the vehicle technology evolved to meet the emerging regulations. New vehicle technology has shifted surface tribology more towards boundary regime as new designs are compact, offer high operating temperatures and pressures.

In the light of major research work carried out on the detrimental health impacts of ultrafine particles (<50 nm), Euro VI emission standards incorporate a limit on particle number, of which ultrafine particles is the dominant contributor. As Compressed Natural Gas (CNG) is a cheaper and cleaner fuel when compared to diesel, there has been a steady increase in the number of CNG vehicles on road especially in the heavy duty segment. Off late, there has been much focus on the nature of particle emissions emanating from CNG engines as these particles mainly fall under the ultrafine particle size range. The combustion of lubricant is considered to be the dominant source of particle emissions from CNG engines. Particle emission due to lubricant is affected by the oil transport mechanisms into the combustion chamber which in turn vary with engine operating conditions as well as with the physico chemical properties of the lubricant.

Advances in renewable energy sources and impact of green house gases on climate change have led intense research in the area of renewable energy for transport and power generation sectors. All over the world gaseous fuels have gained momentum as an ideal alternative fuel for meeting future energy needs. Hydrogen enriched compressed natural gas (HCNG) may be considered as an alternative automotive fuel which does not require any major modification in the existing CNG engine and infrastructure. Several studies of HCNG fuel were reported on small and light duty engines / vehicles, but limited reports are available on heavy duty engines. In this study, experimental investigations were carried out on a 6 cylinder heavy duty CNG engine which has been optimized for 18 percent HCNG. Initial performance of the engine on HCNG was compared vis-à-vis CNG and, thereafter, the engine was subjected to endurance test as per BIS 10000 norms for 100 hours (severe cycle) with HCNG.

It has been reported that 90% of greases are used for the lubrication of rolling element bearings. Greases are important systemic components which greatly influence the life of the bearings besides the dynamic test conditions encountered throughout its operation such as load, speed, temperature and bearing design. The greases may be used in bearings running in open condition or using shields to prevent it being leaked or thrown off during operation. The dynamic life of grease is determined by tests run on multiple sets at elevated temperatures till failure is encountered. These tests measure the grease life as well as the bearing life. Simulated tests in conditions close to real life applications are possible using this method. The FE9 test rig is one of the commonly used test rigs for finding the dynamic grease life.