A four cylinder 4 stroke diesel engine has a bore of 212 mm and stroke 292mm. At full load at 720 rpm the brake mean effective pressure is 5.93 bar and specific fuel consumption is 0.226kg/kWh. The air fuel ratio as determined by exhaust gas analysis is 25:1. Calculate the brake thermal efficiency and volumetric efficiency of the engine. Atmospheric conditions are 1.01bar and 15°C. The calorific value of fuel may be taken as 44200 kJ/kg.