Just did our first oil change (Mobil 1) at 4200 miles. It's a breeze with that top-mounted oil filter replacement! Curious to see the results, but they will probably be statistically misleading as we are entering summer blend gas season, temps are rising, and I just bumped up the tire pressure a little.

FYI--one of the advantages of the GM BAS system is obviously its simplicity. Some wouldn't consider doing simple stuff like oil changes themselves on a hybrid, but this one is as easy as the conventional version. It's literally a 10 minute, mess-free job. If you do it yourself, hop over to Pepboys or some other cheapo auto parts store and pick up a 32 mm low-profile socket for the oil filter housing. It's a common part since all Ecotec engines use it, and it makes the job a cinch.