While Quaker State Defy has an apparently adequate level of ZDDP, using a synthetic motor oil in an older engine is usually bad news in my experience. Every single enthusiast I personally know that has tried synthetic motor oil, save for one, in their older auto has experienced engine seal oil leaks. The Internet contains hundreds of articles and testimonies to that occurring. I would be very leery of using any synthetic motor oil in these old engines. I won't take the chance.... Valvoline VR-1 Racing Oil has a high content of zinc-phosphorous and is not synthetic. It's available in a wide variety of viscosities. I've used their 20W-50 for some time in my "F" and in my Chevelle SS LS5. Viscosities available: 10W-30, 20W-50, SAE 30, SAE 40, SAE 50 and SAE 60 Mike Reed ----- Original Message ----- From: Mark Souders To: Chrysler300@xxxxxxxxxxxxxxx Cc: jpeabo@xxxxxxxxxxx Sent: Wednesday, January 09, 2013 7:15 AM Subject: Re: [Chrysler300] Zincified oil for a C-300? I used to use Rotella motor oil on the advice of my wife's boss, who is the manager of fleet maintenance for a major battery manufacturer. But just over a year ago Quaker State introduced their zinc enriched Defy brand motor oil. If you Google search "quaker state defy" you'll find lots of info about it. I've been using it in my 300H and my 79 Jeep CJ7 and have been fully satisfied with it. No leaks, no drips, and the bonus is 1 MPG improvement in fuel economy in my Jeep. I haven't checked MPG on my Chrysler yet. Regards, Mark Souders 300H Mohrsville, PA -----Original Message----- From: Rich Barber c300@xxxxxxx> To: chrysler300 chrysler300@xxxxxxxxxxxxxxx> Cc: jpeabo jpeabo@xxxxxxxxxxx> Sent: Wed, Jan 9, 2013 2:31 am Subject: [Chrysler300] Zincified oil for a C-300? John Peabody was trying to get this message on the server. Ive seen some igh-zinc oil and additives advertised but have not kept the information andy. Anyone having a good answer for John, please send it to him at: peabo@xxxxxxxxxxx ich Barber Has the 300 group come up with a zinc replacement or a zinc additive for ur flat tappet brutes? Everything I come up with is a synthetic oil or a lend. I stored my C-300 without changing the oil knowing I'll have till pring to come up with an oil or a zinc add. My friend added synthetic il in his Chevy 409 and sprouted leaks. My Chrysler is the only car I ave, new or old, that doesn't leak and I want to keep it that way. The ight choice should work for the 'old man' or the 'hot rodder' type driver. hanks, John and Nancy Peabody ----------------------------------- To send a message to this group, send an email to: hrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or o to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave roup" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! roups Links Individual Email | Traditional http://docs.yahoo.com/info/terms/ [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/