The van is a '92 3.0L V6 Aerostar. It has 109,000 miles on it. It's last two OCIs have been synthetic (Synpower 1800 miles and NAPA 4000 miles). Prior to that it was years of Durablend. The NAPA has been in there since Feb 4 and is at 3600 miles now and included half a quart of Redline at the onset of the OCI. The oil change would be around the end of August. The van uses a quart about every 1300 miles and seems to "prefer" something a bit thicker than the average 10w30. Here are the possibilites I am considering (all in my stash): 1) Maxlife Synthetic 10w30 (SL) 2) Citgo Ultralife 10w30 (SL) 3) Redline 10w30 4) Redline 5w20 5) Pennzoil Platinum 10w30 (SM) 6) Havoline Synthetic 5w30 (SJ and SL) I probably would thicken up #5 or #6 with half a bottle Valvoline Synpower Oil Treatment. The Maxlife Synth and Citgo Ultralife already are thick enough. I am actually itching to try the Redline 10w30 in it, but wondered if it would take the Redline 5w20. Oil pressure on a 11.5 cSt 10w30 is around 40-42 psi hot at 2500 rpm (also at 2000) and around 13 psi hot at 700 rpm. Spec is 40 - 60 psi at 2500. So I think the 20 weight might be a bit too thin for it, though the HTHS is probably what really matters, right? The 5w20 has an HTHS of 3.3 and the 10w30 is 3.8. Or maybe a mixture of 5w20 and 10w30? Also, it handles Detroit winter starts fine on 10w30.