I know you set it by adjusting the rear cam but when do you do it? When engine is cold or when at full temp? Also does anybody know what to set it at? I read it should be 0.6l/h but my mpg went down to average 35 mpg from 38-40 mpg. So i put it back to 0.4l/h (when at full running temp). The reason i ask is because my car puffs out some diesel smoke when starting from cold.