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To tackle the problems associated with the volatility of crude oil prices and ever stringent emission norms, oil industries and automobiles manufacturers are experimenting with various alternative fuels to increase its percentage share in the energy mix and to reduce the vehicular emissions. Alcohols are preferred choice of alternative fuels for the gasoline engines as it does not require any major engine modification and new infrastructure for the fuel distribution network. Ethanol as sole fuel or blending component for gasoline for use in spark ignition engines has been investigated many decades. Currently, 10% ethanol is blended in motor gasoline in India and the ethanol concentration may be further increased in future. In order to study the effect of higher blends of ethanol (upto 20%) on engine in-cylinder combustion, performance and emission, investigations were carried out on a latest generation passenger car engine in a climatic controlled test cell.

Ambient temperature conditions, engine design, fuel, lubricant and fuel injection strategies influence the cold start performance of gasoline engines. Despite the cold start period is only a very small portion in the legislative emission driving cycle, but it accounts for a major portion of the overall driving cycle emissions. The start ability tests were carried out in the weather controlled transient dynamometer - engine test cell at different ambient conditions for investigating the cold start behavior of a modern generation multi-point fuel injection system spark ignition engine. The combustion data were analyzed for the first 200 cycles and the engine performance and emissions were analyzed for 300 s from key-on. It is observed that cumulative fuel consumption of the engine during the first 60 s of engine cold starting at 10 °C was 60% higher than at 25 °C and resulted in 8% increase in the value of peak speed of the engine.

Alcohols are preferred choice of alternative fuel for gasoline engines to tackle the problems associated with nation’s energy security and environmental pollution. Ethanol can be used as a sole fuel or gasoline blending component for use in spark ignition engines. BIS Specification 2796: 2013 permitted to blend 10% ethanol in gasoline and the concentration may be further increased in coming years in India. Research on combustion of ethanol blended gasoline on modern gasoline engine is highly desirable. This paper highlights the experimental investigation carried out on the latest generation multipoint fuel injection system passenger car engine fueled with ethanol-gasoline blends in a climatic controlled test cell to study the in-cylinder combustion, performance and emission characteristics. Part load tests at regular speed intervals were conducted using ethanol blends. Combustion duration decreased with increase in engine load and speed for the all test fuels.

Diesel engines are the versatile power source and is widely used in passenger car and commercial vehicle applications. Environmental temperature conditions, fuel quality, fuel injection strategies and lubricant have influence on cold start performance of the diesel engines. Strategies to overcome the cold start problem at very low ambient temperature include preheating of intake air, coolant, cylinder block. The present research work investigates the effect of coolant temperatures on passenger car diesel engine’s performance and exhaust emission characteristics during the cold start at cold ambient temperature conditions. The engine is soaked in the -7°C environment for 6 hours. The engine coolant is preheated to the desired coolant temperatures of 10 and 20°C by an external heater and the start ability tests were performed.