Originally Posted by bigx5er

I just returned from driving my X5 35d 3500 miles from Minnesota to Las Vegas and back. The mileage was good, but not great at 80 - 85 MPH. I averaged around 24.5 MPG (measure and calculated by hand, the computer showed a little worse).

Worst I saw was 19.9 in high winds and best was 26.9 coming down from the mountains.

I've done the same trip/speeds in the 3.0i a few times. With that I averaged around 21.5 MPG.

The good news was diesel was cheaper in most states than premium. In Minnesota, diesel is currently .25 above premium.