keep in mind that the extra gears are there to keep an engine in its power band during acceleration to minimize emissions. modern engines don't produce the low rpm grunt that our engines do. so things like the extra gear down low and 2 overdrives you're going to find that you're rarely using certain gears or you end up with two shift points where you would normally have one. Now it would increase fuel economy and probably won't do what you think it will since the 3800 works so well on wide gear ratio spreads