The efficiency of new fuel injection helps a lot too. Not like old carbed engines that might be running bad due to flooding, or any other reason for over-fueling. I still can't leave conventional oil in longer than 3500 or 4000 miles. My wife's terrain has 8000 miles and has had 2 oil changes. The dealer told me not needed yet, I said change it! My co truck is gas engine, and idles ALOT. It gets changed every 3000. Maybe I'm wastin $$, makes me feel better. Of course my Z every 3000, same for any other carbed engine I have.