I did about 400 miles yesterday, mostly motorways with a few minor traffic jams. All seemed well, car behaved itself. Went out this morning to check it was alright and found it had used more than 50% of the oil ! I checked yesterday morning before starting off and it was about 90% up the dip stick, checked again this morning and it was a maximum of 20% up the dip stick. God knows what would have happened if I'd gone the long way round !