winter fuel consumption

[Tony Hoffman]

MTBE is what they used when I lived in MT. It was on the sticker on the pump
in the winter months. I believe it was in teh area of 15%. Don't know if
that's still the case, I didn't pay attention when I was visiting
Thanksgiving. However, here in Houston, they just use E10, but it doesn't
get cold, either.

Tony

On Wed, Jan 26, 2011 at 9:08 AM, Kunz, Bob <bob.kunz at hp.com> wrote:

> Interesting a lot of people assume MTBE is pervasive in US gasoline, it is
> not. E10 is the norm. Both are in place to add oxygen content to fuel
> (originally) to reduce emissions. However, with current emissions systems in
> cars, neither is needed. E10 is there to satiate the ethanol producers. Your
> 200 would probably like E0 better. My '86 5Ks sure does.
>
> Fuel is blended seasonally and this changes the vapor pressure which can
> lead to your symptom. At fuel cut off in open loop as you change gears the
> mixture will go lean giving a momentary RPM increase.
>
> Fuel ecomonmy as others have pointed out is a simple thermodynamics issue.
> The engine has to produce more power to overcome the additional demand on it
> in winter driving. What percentage drop are you seeing? I wouldn't be
> looking for something wrong even up to 25%.
>
> --bob
>