Your stochiometric ratio became leaner somehow.  CO adjustment?  If you
find the answer and it is repeatable, it will be a compelling argument
for the inline four conversion.

-Dana-

David Marshall wrote:
...
> trip through rolling hills at a leasurly 95 to 100km/h - this translates
> into 8.8L per 100km (26.7 US mpg)- the trip back we did a little more speed
> ranging from 100km/h to 115km/h plus really pushing hard in 3rd going up
> some of the steep hills - we consumed 14L of gasoline or 11.2L per 100km
> (21 US mpg).
>
> So, why did things get better with a throttle that opens quicker?  Not that
> I am complaining!
>