Agreed....if you go dino oil, change at 5,000 mile intervals (the 3,000 mile is definately overkill in this day & age)......synthetic will last longer so 'down time' will be less as well. It sounds that many of the miles you do is highway.....another reason why using a longer drain interval is better.....highway miles are nothing on our Lexi or the oil. Just something to consider.