Hi ! I’ve been having a few strange things with the BC since about 2 tank fillings with my 2.5 DTI. I’ve only filled up 6 times since I got the car. I always zero all the values of the BC when refueling. With the first 4 refuellings the values of the BC have always exactly tuned ( always calculate with Excel after). That means: absolute consumption BC e.g. 64 liters and then went on the tank also about 64 liters. On average e.g. 7,1 liters according to BC, it was then 7,1X. So everything was ok. But since two tank fillings h This is why the average consumption around this delta is no longer correct. But now my question: where does this come from? Is this because my WR has a smaller size (195/65/15 WR to 225/55/16 SR) ? How is the average consumption calculated ? Is the consumption calculated from the absolute consumption ? It should not be related to the tyre size. Does anyone have an idea ? What can I use a How is the absolute consumption determined ? Greeting Karle P.S. The 2.5 DTI has a heater as far as I know … goes the electric or with diesel ? If with diesel … the consumption is included in the BC ? From which temperature does the heater start to work ? Does it work only when the engine is cold ?