Oddly enough I don't seem to have a wide variation on fuel consumption on the '99 I am driving right now...I use about 5 or 6 litres to go 45 minutes on the expressway with about 5 minutes of that in stop and go traffic...to and from work..so the total is 11 or 12 litres.. the '96 used about the same amount and it had about 300K kilometres
The temp the past couple of days has been minus 14 to minus 18...and the only extra fuel I use is for idling...