The formula that I have used for many years and vehicles is to run them normally in city driving for the first 500 miles under 60 mph using petroleum oil, change the oil to a good grade synthetic, I like Mobil 1, and then drive normal for the next 1500 miles at no more than 70 mph and change the oil again and of course always using a good oil filter. I have never had a problem with high oil consumption between changes or an engine problem that was not self induced due to racing and over revving the engine.