stoutdog wrote:
think of it this way. If the engine running at 2200RPM at 0% throttle injects the same amount of fuel per stroke as an idling engine, and the engine running at 2200RPM significantly improves your ability to coast, then what on earth could possibly be the advantage of cruising at lower RPMs?
With GDE, I can take my foot off the pedal and cruise for much longer distances than before, all while watching my EVIC climb at a rapid rate.
I think that you are missing the point entirely. The advantage in coasting at idle vs coasting at 2200 RPM is that, for every meter traveled the engine has to turn X many times. At 2200 RPM it is turning 3 times faster than idle speed for every meter traveled forward. If fuel is being injected at every power stroke of the engine, three times as much fuel is being used to travel the same distance.
Now Danoid may also be right in that our CRD can enter what is known as "deceleration fuel cutoff" mode in certain situations. In most modern vehicles however, the DFCO parameters are temperature dependent, and are only used momentarily in stop and go situations.
If GDE has indeed improved the coasting distance which may be achieved when letting off of the pedal, it could only be by adding more fuel to the engine during the coasting event. There is no other parameter to adjust. This being the case, coasting in gear with the GDE tune "should" use more fuel than coasting out of gear.
I am not encouraging anyone to coast in neutral, because not everyone can do it safely. Nor am I coming down on GDE. I think highly of what they have done, and plan on getting their tune as soon as I'm rich and famous.