Use what the owners manual or oil cap tells you. On a friction brake tester nothing beats Motorcraft 5-30 or 10-30 syn blend oil. I use
10-40 in a 8 second twin turbo 347
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Retired Ford Engineer
2005 Gt Mustang 1993 twin turbo 347 Digital Fuel Injected 1979 Digital Injected 347 Five speed 2008 Ranger FX4 extended cab 4.0L auto tran
Damm 0W-030 isn't that too thin a viscosity?
My engine builder uses 5W30 Valvoline SynPower with NO additives like Lucas, Zmax Etc..
Flows like water when cold, sticks like honey when hot. Factory specs call for 5w-20. Factory specs are concerned with overall CAFE goals. If you haven't heard of Militec 1, google it. It is not an additive in the traditional PTFE, teflon way. It chemically bonds with the metal. My car (03 Cobra) was built during the dreaded "tick" time frame....I have no "tick". My last 5.0 (a nasty notch) was fed a similar diet. It finally died with 227,000 hard miles, six transmissions hard miles. That car was in hundreds of impromptu street "contests" and more than a few tickets. During a few of those powershifts I missed (CRUNCH, KABOOM, DAYUM! DAYUM !DAYUM!!! there goes third) RPM's often hit stratospheric levels. I like my formula but whatever works for you.
Factory spec are usually for better fuel economy, clearances and so on. i'll have to check out the Militec 1, those others are snake oils.
Snake Pliskin, you live in Lenoir City? I'm from Harriman in Roane County, about to be back there in 25 days.
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1995 Mustang GT-Heavily Modded-Sold 2003 Ford Lightning-Sold 1997 Saleen-5.4 conversion-Sold 2005 Mustang GT-Torch Red-Sold 2003 Mustang Cobra-Oxford White 2003 4Runner V8 Sport Edition 4X4
Where can I purchase this Militec product and how many ounces would I add to my 99 Cobra?
My Newly built forged motor just had its first oil change at 600 miles, did conventional again, gonna change after 1000 more miles then switch to synthetic, is that when I should add the Militec? Thanks..
What Brand and Weight oil Fellow Comrades? 
