I've pretty much settled on 5W30 as being my oil of choice: A hotrod magazine article reported the largest horsepower gain using that grade of oil Using a super-grade synthetic, like Amsoil should lay to rest any concerns about adequate flow, and lubrication, or breakdown of the oil. I've used the Amsoil motor oil in all my vehicles, from V-8's to 4 cyl. Porsche engines, and have "enjoyed" the extended drain intervals. On drain intervals: Amsoil says their product can go 25,000 mithout a change. Supposedly at 12,500 miles you should change the filter, and add a quart. But I just opt for changing the oil and filter at 10,000 miles- period. Even doing that keeps the costs in line with other brands of oil, and I still get to enjoy the superior components of the synthetic product. Some time back I asked AMsoil about mixing grades of oil. Example adding a quart of 20W50 to my usual 5W30 to "stiffen" it, and asking would the grade then change from 5W30 to 5W50? They (Amsoil) advised that it would be like mixing golf balls, and base balls. The properties of the 2 grades of oils would not mix, and they recommended against it. I can report though I have had no problems what so ever with using the 5W30, even in a 4 cylinder high performance engine. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/