An engine is used on a job requiring a shaft output of 100 kW. The mechanical efficiency of the engine is 80% and it uses 30 kg of fuel per hour under conditions of operation. Calculate the indicated thermal efficiency. if an improvement in engine design reduces the frictional losses by 5 kW, calculate the amount of fuel saved per hour. Assume that the indicated thermal efficiency remains the same. Calorific value of fuel is 42000kJ/kg.