It's got to be going to one of the three places you've identified. I suggest you look at the exhaust closer and perhaps remove the spark plugs.

Haven't we been here before?

Anyone any ideas?

Either equally worn piston rings or one (or more) cylinder with broken one(s). Look at the plugs, and/or do a compression test. Can it pass an emissions test? If so, use a 'thicker' oil till it dies! Sounds as though it's been neglected - or thrashed.

For reference, at that mileage our 1.6 Zetec required three 500ml top-ups from its oil change at 102,800 to another change at 114,100. Adding another 500mls between top-up level and change level (I change to half-way and drain at minimum or just below on the dipstick) that's only 1litre every 5-6000m. But as (almost) all regulars know here, I carefully service my engines;-)

Edited by John F on 16/08/2018 at 12:14

My 1.4 petrol Fusion is using about a litre of oil every 500 miles. There are no leaks, there is no oil in the coolant and there is no smoke coming out of the exhaust. The car has done 105k miles. Anyone any ideas?

How do you know its not going through the exhaust, if your driving and its smoking you wont see it as it dissipates too quickly, have a compression test done and that should tell whats wrong, probably valve seals/guides rather than rings

Rings would cause oil burning all the time so if you looked while stationary it would show as blue smoke

My 1.4 petrol Fusion is using about a litre of oil every 500 miles. There are no leaks, ...

Are you saying that if you lie on the floor, the underneath of the front end is absolutely free of any sign of oil drips?

Edited by Andrew-T on 18/08/2018 at 00:08