Originally Posted by JCMorrill
This is the "why" for this whole discussion that I was looking for. Because I couldn't see how it would make ANY difference in fuel economy no matter what you did -- other than to burn gas you might not have to by trying to save the Stealth miles until later. Which was all I was trying to say (long windedly, I guess) earlier.
But now that I think of it ... It does beg the question: What benefit from an overall average carbon footprint/fuel burn position did it actually create for Fisker to limit our options to just "sustaing" at 0-26 Stealth miles in the first place? The same argument that allowing the engine to recharge the battery to 100% doesn't save you any fuel, works in the other direction ... it doesn't cost you any more fuel either as long as you use the 50 Stealth miles somewhere on the trip. The only thing that "sustain only" mode does do is force you to use at least 24 miles per charge from Electricity.
could have fairly turned all my questions around on me. Why didn't Fisker allow us to keep maximum power availability when it doesn't actually burn more fuel to do it that way? (Again, so long as you use your Stealth miles somewhere on your trip)?
There has been a fair amount of discussion about this since the beginning. The first tier owners will remember that one of the reasons the car's release was delayed significantly was that Fisker submitted the cars for EPA/Cal-AQMD certification very late in the game, and because the ICE used by Fisker was already a few years old at the time, it was having trouble passing emissions standards if it was used to charge the batteries on the fly as well as power the car. In order to get past this hurdle, Fisker worked out a deal with the certifying agencies to pass the car, but only if the ICE was restricted to run in a limited range, which resulted in the compromise algorithm in the car.
At the time, Fisker was under enormous pressure to release the cars, and they did not have the luxury of appealing the findings, fighting for a new standard for Hybrid Plug-ins or to re-engineer the power system. As a result, they accepted the deal and moved on.
is doing today has the benefit of several years of operational history and plenty of time to perfect the design and the engineering, plus a dedicated and talented engineer to do the actual work without investors breathing down his neck to release the features before they are ready.
As an owner and Fisker enthusiast, I am very grateful to @PowerSource
for spending his own time and money coming up with significant improvements for a very very limited market of vehicles and I think his efforts, and anyone else's who wants to do this, should be applauded and supported by the Fisker community. I personally know a lot of Karma owners. Some of them would never change the stock Karma because they are happy with what they have and don't use their cars very much. Others, like myself, are eager to get improved performance and features from their cars. Regardless of where you fall on that spectrum, it is always better to have the option that not.