So, I noticed my '06 6s fares poorly (with respect to mpg) in the winter. In the summer I get between 20 and 21 mpg in the city, where as in the winter I get between 17 and 18 mpg in the city. My thought is that a CAI will worsen this problem in the winter, as the air flowing into the engine is even colder, slowing the warm up to optimal temperature even more.

So, could an SRI have better performance in the winter then a CAI, just because the under hood temp is never going to get that high?

I figure that in the summer I could just coolant bypass the TB, preventing the temperature under the hood from being too drastic.

Basically, my hope would be that this could raise performance in the winter, and in the summer have temporally better power or, at worst, the same amount of power.

I bother with this distinction because I wouldn't buy a CAI unless it's the CP-E version, and I can't see having $550+ to cough up on something unnecessary for my car for at least another year and a half.

 

To first answer your question directly, my vote would be no.It won"t make any difference,
You are no doubt getting poorer mileage in the winter due to the "winter" fuel mix. You are in Indiana, right? Don"t theyadd ethanolto thefuel for the winter time up there... up to 15%?
That in and of itself would reduce mileage @ least 10%, because unlike gasoline, ethanol carries it own oxygen molecule with it, and therefore the fuel system must go to a richer mixture (more volume of fuel)to compensate for the extra O2 tomaintain optimal fuel/air ratio.
I read once based on a gallon to gallon ratio (1:1,) any alcohol fuel is only 66%, or 2/3rdsas efficient as gasoline because of the O2 it carries.(R&T Magazine, circa 1992, Alternative and Racing Fuels.) If that O2 molecule could be removed it would be just as efficient as gasoline, but thenit would no longer be alcohol either.

 

Yes I live in Indiana, but I thought we had the same high ethanol crap all year, but maybe we don't use it all year, and that would be it.

Yet another reason why I don't like Ethanol, especially what we have based off of corn. I guess I just have to wait till get that damn CP-E.