Ethanol and Cylinder Deactivation: '08 Impala

[rh77]

I'm currently in the midst of renting a 2008 Chevy Impala LTZ with the 3.9L V-6 "FlexFuel" engine and "Active Fuel Management" (the GM "LGD 3900" engine).

One tank of 4-passenger driving, with an average of 52 MPH, resulted in 24.3 MPG. The advantage to this engine is the the cylinder deactivation and E-85 capability. This engine was tested in the Monte with a non-Ethanol compatible engine a month ago or so. The 3-Cylinder engagement proved to offer no advantage to the 3.5L base engine, or to that of the regular 3.9L. Will Ethanol offer more available power and torque to shut down half of the cylinders, more frequently?

One more day will tell. A relatively full tank of E-85 is nearly empty from this cross-Missouri expedition. (for those in another post, I passed "Nostalgiaville, USA twice, argh). Bo-ring. MO I-70 sux.

Previews: With Ethanol, 3-Cylinder operation holds on longer with the added octane rating and available power-to-load calculation. Even still, FE is much lower, begging the inquiry: is it worth it? I paid $2.40 per gallon for E-85 vs. $2.90/gal. for 87-octane regular. Tomorrow will reveal the final tally...

RH77