A method and apparatus for reducing fuel consumption in an internal combustion engine including gasoline, petrol and diesel engines used in trucks, cars and for pumps including the steps of providing a thermal insulation shield that includes reflective fabric over the exhaust manifold, around the intake plenum for intake air and intake air box, covering the turbo charger compressor with a heat insulating material that includes a reflective fabric layer and the turbo charger drive turbine housing except for the bearing area to greatly reduce heat build up in the engine compartment thereby reducing intake air temperature for increased engine efficiency. The invention has been found to increase fuel efficiency in large trucks by ten to fifteen percent. The materials are light weight and do not significantly increase engine weight or truck loan weight.