Hmmm, the sons 1.6 2002 petrol focus has recently used quite a bit of oil but its being totally inconsistant about it.

The car has 136000 miles racked up and i expect it to use some black stuff but lately he had to top up over about a month and used about a gallon while covering about a 1000 miles.

Over easter we took the car away with us and covered another 800 miles within 10 days with no oil usage at all.

There are no leaks or drips and we are using the correct grade, 5w/30.

Any suggestions or ideas whats going on here ?

The engine management light comes on from time to time but there are no error codes stored and the light seems to come on just as the oil level drops to near minimun,but the oil light itself has never came on as we check the car daily to be on the safe side.

Is there evidence of oil leaking onto the ground when the vehicle is parked up?

I had the same car and the same problem. I would sometimes see very small amounts of oil on the driveway. But the car used a hell of a lot of oil, had to top it up a lot. It turned out to be the oil filter, it was really old and had gone pourous. When the car was stationary, there was very little leakage, but when I was driving there must have been a lot. This explained the high loss of oil but very little evidence on the driveway.

Oil filters can be replaced very cheaply so it might be worth doing that to start off with.

Having had the same engine and the same oil guzzling problems i know exactly what you mean. My engine had no leaks but like yours it inconsistently used oil.. sometimes very little other times an awful lot.

It seems that piston rings are the favourite suspect for most who have this problem

Much googling also points to piston rings maybe sticking,apparently with a diesel its ok just to rev the horlicks out of it which burns off the crud but its a no no with a petrol engine.

Anyone have any ideas or solutions ?