JFB Tech

Any ideas? My 2002 Mk III Mondeo with the 2.0 Duratec HE engine is currently consuming a litre of oil per 100 miles. No sign of leaks underneath, its always dry where I park at home and at work and there's no sing of oil on the back bumper (as I've seen with external leaks on other cars). There's no smoke from the exhaust and she passed her emissions test on the MOT a couple of months back. I'm at a loss.