I'm up in Va visiting my aunt but will be heading back to SC tomorrow. Saturday was an almost non-stop 70-75 mph run of about 370 miles. The 3.4 in my Olds van ran as smoothly and quietly as it ever has. I didn't see any noticeable improvement in MPG versus when I use to use Mobil 1, however. Power is noticeably up, but I posted about that before in an Auto-Rx post. I think we can attribute that to the Auto-Rx cleaning the ring pack and improving compression. After letting the van sit overnight I checked the oil and it was still on the full mark. So this relatively "hi-speed" interstate run didn't cause any abnormal oil consumption with the 5w20. (My engine is tight and has never consumed any measurable amount of oil between changes, so I really didn't think it would use the 5w20 any more than it would 5w30.) I'll be heading back tomorrow, and temps are supposed to be a lot warmer, so we'll see how she does on the return trip.