A vehicle under specific conditions will get a specific mpg from the
energy of a specific fuel - depending on the calories or BTW's in a
specific quantity of the fuel. Gasoline has more btu's/calories than
ethanol. Ethanol is ethanol whether it comes from corn or sugar cane or
kudzu vines (my favorite choice for making ethanol - the kudzu vine is
taking over the south. Lets use it for fuel instead of corn). If you
dilute your 1 gallon of gasoline with 10% ethanol, the 1 gallon of fuel
will no longer have the total btus/calories that it has as a gallon of
pure gasoline, so you are not going to get the mileage from it you would
from the gallon of pure stuff.

As for vapor lock, I'm not really sure. Which of the two - gasoline or
alcohol - is the lighter weight fuel with the greatest volatility? Which
ever is the lighter of the two will tend to separate and vaporize
causing vapor lock. . However, on high pressure FI systems that would
most likely  not be a problem

John Rodgers
88 GL Driver

Scott Foss - Shazam wrote:
> That's what I got too.
> Breaks for farmers that make over 300K a year or something.
>  Sick !
> I'm wondering if 10 % ethanol fuel vapor locks more easily in high temps.
> My 1970 carbed Mercedes has had two clear cases of no liquid fuel to the
> engine, both in very hight temps.
> one just the other day in 100 degrees.
> i'm going to put on a pusher electric fuel pump in back by the tank.
> and increase return flow to the fuel tank from the engine........both of
> which should help a lot.
> but ..........do you have an opinioin or real informatioin about if 10 %
> ethanol gas can vaoor lock more easily ?
>
> of course on our 30 psi fuel injected vanagons it's way less likely to
> be a problem.
> My gas pump jocky said people with newer cars said they 'maybe' got
> slightly better fuel mileage with 10 % ethanaol gas, but i got the
> imporession that was just by impression, and not calculation.
>
> any thought on the vapor lock issue ?
> thanx, scott
>