[SentraSE-R]

I just finished reading the 26 pages in this thread. Some of the participants like Zman, JanGeo, and Blackbelt were here when I first signed up.

To answer one of your original questions, the xB does have deceleration fuel cut-off. DFCO comes into play when the engine throttle position sensor notices a drop to idle position with the transmission in gear and engine rpm >1500 (in our xBs). So, you're correct that you can coast down hills and to stops using no fuel under those conditions. However, your coasting distances are shortened by coasting in gear, and it's possible you'll get better fuel economy coasting in neutral for longer distances, even with engine on.

DFCO varies with different cars. My wife's 2006 Hyundai Elantra doesn't have it. My 2002 Nissan Sentra only went into DFCO above 2500 rpm, which was ~65 mph in 6th gear. That made DFCO mostly useless for me, since I don't drive >65 mph very often.