This is my first post, been searching and reading for several months, but my first problem. Great board by the way. I was running Pennzoil High Mileage 10w30 in my Ford Explorer for the first time, I did the 2 treatments of auto-RX already, and the first oil change after the auto-RX I ran Chevron 10w-40 ISO-PURE or whatever it is in that standard blue bottle for 1.08 at WalMart. 3000 miles with that, ran great, for some dumb reason I saw that Pennzoil high mileage oil was going to be better or the same or something, I guess the high mileage marketing took me for a ride but here is what happened. my wife and I went on vacation about 300 miles after I changed the oil to Pennzoil HM, ended up driving approximately 2000 miles in a bit over a week, some of the driving was through mountains, 100+ degrees heat index outside, city driving, but mostly highway around 2500-3000 RPMs. oil pressure was lower for at least the 2nd 1000 of the miles, so back home finally I ran it for another 2 weeks and just yesterday the check oil light came on, now granted I checked the oil several times on the road because I noted the pressure was less, and it always read fine, just as it did yesterday with the check oil light on. so no idea what to do, I dumped some old bottle of Mobil 10w40 I had in our garage in the crank case to see if may it was low and it just didnt show up right on the stick. The light went off, so I decided its time to change the oil a couple hundred miles early. when I got back from Walmart popped open the oil drain plug and the stuff rushed outta there like coffee, very thin and fast flowing. I am guessing it was low and the oil was so thin it was splashing up on the dipstick still reading high. Does not seem like this Pennzoil HM oil holds up very well. The Chevron did much better granted it was a 10w40 but I figured the HM should be close to a 10w40 anyways. Now I have never driven any other oils in this truck in those type of conditions I did, but I am not going to be buying that oil again. I put in Pennzoil Long Life 15w40 to see how that works out for me, if it is no good, I am going back to Chevron. any comments or ideas why the HM oil would have broken down to water like oil in less than 3000 miles?