Yes, you can get 600+mpg in your MINI.

How?

Drive to the top of a big hill on a highway. Westbound I-80 in Wyoming at the top of the Continental Divide heading toward Laramie will work.

Crest the hill at 75 and head downhill. Shift to neutral (I have a manual transmission) and glide. You'll soon be over 600mpg! Maybe not for long, but...

I have a new OBD II reader I'm playing with. It shows mpg to 3 digits, not 2 digits like in the MINI. I'm going to find some BIG hills with long downhills in Colorado and see if I can break 1,000mpg.

OK. Back to the serious discussions.

 

Funny stuff............

Now check your mileage going the other way?

 

I can get nearly 600 miles from a tank

 

You can do even better by keeping it in gear (cuts off fuel) down hill, however you might not go as far as having it in N or GreenMode glide because of the engine brake.

The best I got was around 47mpg during a long road trip cruising at 55mph. Cruising at 65 would lower the mileage to 42mpg.