[euromodder]

My motivation isn't financial, despite our high fuel prices.

In 2011 I've done 23.664km @ 4.70 L/100km or 1.113 L
In 2008 I've done 23.565km @ 5.72 L/100km or 1.348 L

That's 235 L / year difference (62.1 gallon), which saved a mere 295 euro that year, or only 25 euro/month.

Not much of a reward for using 17.5 % less gas, is it ?
That's the law of diminishing returns at work, when you start above 40 mpg .