The last oil change was the one they did when the head gasket was replaced. There were no oil leaks, no smoke, no noises, can't be sure how often oil level was checked as my son was using the car. They claim that the "SAE" standard is that an engine with over a 100K miles will burn a qt. per 1K miles on average. So they claim having driven 2500 miles it could have used between 2.5 to 3 qts of oil. When I checked it after we had it towed to the dealer it was down about 1.5 qts. They say that the cams being the furthest out would starve for oil first.