[AT] GM Flex Fuel vehicles

[Henry Miller]

On Sunday 13 August 2006 00:25, Steve W. wrote:
> Henry Miller wrote:

> >> The last change is in
> >> the injectors. Since alcohol has less energy than gasoline they
> >> increased the flow rate for the flex vehicles to accommodate the higher
> >> rate of fuel flow.
> >
> > WRONG!    Yes the injectors are bigger, but it is not because ethanol has
> > less energy (though it does).  Injectors are bigger because ethanol needs
> > to run richer than gasoline.   Gas needs an air/fuel ratio of about 14:1,
> > while ethanol is about 9:1.   Without the bigger injectors your engine
> > runs too lean.   Over time (thousands of miles, one tank of E85 is not
> > problem) this can burn a hole in your pistons.
>
> Same thing different wording. The lower energy of the alcohol means that
> in order to generate the same power and tolerate the different mix
> requirements they need to flow more fuel.

I hate to be picky, but this is not different wording of the same thing.   
Ethanol needs to flow more fuel to burn correctly.   The fact that flowing 
extra fuel means you can get as much (or in some cases more) power is a side 
effect.   The reason is to flow more fuel is combustion requirements.