My MFD reagin for the average fuel economy doesn't seem right. It is always changing almost as if it were like the immediate fuel economy thing. On all the other cars I have driven with this feature vw/non vw haven't been like this. They measure of the gas/miles so it doesn't change every minute. Instead of showing my consumption for the tank it shows it for my trip then the next trip it goes back to 0. Is this how its supposed to be in the MKV?