How do I ensure optimal fuel efficiency in my BMW M9?

I recently purchased a BMW M9 and I'm trying to make sure that I'm getting the best fuel efficiency out of my car. What steps should I take to maximize fuel efficiency?

First, make sure your tires are properly inflated. Under-inflated tires can lower your fuel efficiency. Use the recommended tire pressure listed in your BMW M9 manual.

Try to avoid idling as much as possible. Idling uses up fuel without actually getting you anywhere. If you are going to be parked for more than a minute, turn off your engine.

Utilize cruise control when driving on the highway. This can help maintain a constant speed, which can improve fuel efficiency.