right, will keep it brief as it late and I am tired, but this test is in no way conclusive, firstly by blocking the bonnet vent and removing the engine cover you are changing how the air flows within the engine compartment, buy only having one sensor you do not get the picture of the total under bonnet temps, the temperature may reduce in this area but increase in others, secondly, for any test to be meaningful you need a baseline, this test has clearly been done with back to back runs, the ambieant temps have increased but also the latent heat within the engine has increased, first test you are cooling a moderately cool engine with cool air, last test you are testing a warm engine with warm air and cooling curves are not linear, we are comparing apples with eggs!!