What is it with you guys and your strange fuel economy measurements? :-)
Just had some Aussie relatives over and they briefly mentioned that a hire car they had in Ireland was quite good, doing so many litres/100km - I've often thought it'd be handy to work out an easy way to convert from one to the other, so I just did, and thought I'd mention it on here.
Quite simply, divide 282.47534399109202258808558021156 by the litres/100km figure to get imperial (proper) miles per gallon. Or use 280 or 300 to make the mental arithmetic easier, though the result's obviously going to be slightly higher or lower.
And yes, it's not something anyone could have worked out in 2 minutes, just thought I'd mention it.
-- "For want of the price of tea and a slice, the old man died."