24th Dec 12 Hi, Merc 220 CDI estate 170 PS I am so far very pleased with my tuning box the car is lovely to drive with the extra power and lovely increase in mid range torque. On the graphs you sen me there are 2 lines one red and one yellow. There is no key with the graphs so please can you tell me what the lines represent and what units are on the vertical and horizontal axes. I have kept to the settings you sent it to me with and have achieved a 5-8% increase in fuel economy which is impressive especially as I am enjoying using the extra performance. Kind regards Mark