My '02 F150 uses about a qt every 1,000-1,200 miles.
Last change was @ 5,000 miles, but 27 months.
I don't plan on changing the oil and filter again till I have at least gone through the rest of my 0w-20 oil (6 qts), and maybe more.
It may be another 3-4 years till I change it, and at least 7,000 miles would be my guess.
Currently running Pennzoil Platinum HM 0w-20 (and 1 qt of PP 0w-20 top off oil so far) and a Fram XG10575 filter.
I had a coworker that had a mid 90's Chevy that had the truck for 5 years and had only changed the filter 3-4 times in that timeframe, he just added a qt of oil every so often.