Differences on most (if not all) flex fuel engines:
- Fuel Pump
Fuel type sensor (you don't have it, to determine what fuel/mix of fuel is in your tank)
Many GM Flexfuels have different cyl heads than the std gas models
This isn't even considering the computing differences necessary to adjust timing, and knock sensing/reduction for different fuels, the multitude of fuel maps, etc.
Any retrofit kit isn't a true retrofit. It might make a car last a while with E85 in it'* system, and might run ok, but it'* not gonna be reliable, or super long lasting.
As mentioned E85 has a lower MPG due to lower potential energy...
'06 Vee Dub GTI 2 door Tornado Red
- 2.0 Turbocharged, Intercooled, Direct Injected, 6 Speed DSG, Underbody Aero, 17" Classix
- Moonroof, Bi-Xenon headlamps, Interlagos Plaid Sport Seats, 6 Disc In-dash, iPod integration, GTI Monster Mats (winter)
'93 Bonneville SE Purple Pearl H4U package - picked up June 23, 2003, Traded-in June 28, 2007...