>(Mobil1) It's $8 per quart -- but with a 15,000 mile change interval, it's cheaper than mineral oil. You also >produce less waste and crap to recycle. I don't know about yours, but my motors are getting more and more >expensive to rebuild! (ANd I get fussier about them as I get older :-) >Not sure if I'll change a filter/add quart half way through. At that long interval it might be worth oil testing at 10K. >Certainly a waste of money/effort on leakly oil burners. Oil testing is a good idea on extended drain interval engines. If there's one thing that can REALLY affect the performance of any oil its coolant seepage. There are some motors that have BIG time problems with this. The GM 3.1 (Aluminum head) is one! I often have several sets of these heads A WEEK come in for testing and surfacing. I ALWAYS machine the intake on these things and it's ALWAYS warped BAD! You can SEE where the intake gasket has been seeping into the valley! Get enough anti-freeze in the oil and it begins to turn to jelly! If you're going to run 15k drain intervals I would recommend changing the filter at halfway. Take a look at the oil and make sure it's still OK. I once had a diesel Rabbit (47mpg) that I NEVER changed the oil. I ran Mobil1 and changed the filter every 5k. Had around 50k on it when I sold it and was still clean under the cam cover. Another good reason to run GM stop leak tabs in all motors. Helps keep that seepage under control. I currently run about 9k between changes. I did a valve adjustment on my son's Toyota 22r yesterday. I have been using Wal-Mart Synthetic in it as a test. Looked pretty good @75k. But HEY,,, that's just ME! Bruce Hevner -------------- next part -------------- An HTML attachment was scrubbed... URL: http://splatter.wps.com/pipermail/amc-list/attachments/20080318/337d31c2/attachment.htm _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list