why does the consumption miles per gallon bar switches from white to green while driving??

i would asume it turns green at higher speed correct? my best guess would mean it is telling you while green it is giving you the best gas milage the car can perform on. while white is average milage at best adn your not getting the best of what you could be getting.

I'm thinking being in the green of that gauge means you're using kinetic energy. I also think it might indicate that the engine is running at it's best. I see it when I'm in "cruise control" mode and it runs in the green consistently. But it also runs in the green if you're coasting.

I'm thinking being in the green of that gauge means you're using kinetic energy. I also think it might indicate that the engine is running at it's best. I see it when I'm in "cruise control" mode and it runs in the green consistently. But it also runs in the green if you're coasting. It also seems to increase when braking.