Is Amsoil a great oil, IMO yes. I've used them for years in certain applications and still do, lots of great products there, but it is an expensive boutique oil that can leave your warranty compromised if you have some form of engine failure with an Amsoil product in the crankcase that does not "meet or exceed". In house testing or "recommended" is not good enough for Ford, and I sure don't want to be the guy battling Ford's laywers over wording. Doesn't matter if we know the failure is completely unrelated to the choice of lube, who wants to take on that project. Doesn't meet/exceed, purposely running longer than recommended OCI to counter boutique oil costs, not for me.
The cheapest, crappiest API-approved cj-4 mineral lube would leave you under warranty, and the most expensive, and arguably one of if not the best cj-4 lube available, will leave you up a creek. Doesn't make any sense.
Find a decent cj-4, Doesn't matter if Esso, Penzoil, Quaker State, whatever, use a descent filter (Ford, Donaldson, Wix) and dump the crankcase regularly. There are PS's here from first gen and newer with rediculous km's, no special oils, just regular changes and decent filters. Also with the severe dust conditions here, cyl wash/fue dilution and shear are nothing compared to the dust particulate and silica accumulation, 5,000km intervals, maybe 6,000km's on occasion, are the target, and it works. That's here anyway, and my $0.02.
'16 F450 Platinum, dual alts, on board air, Pac Brake bags, Leer cab height, ford dvd to sedate kids, Ali Arc bull bar, Ridge 30" drives/fogs, 225/19.5 M920A's w/steelies & simulators (winter), Wilson cell booster, Kenwood 2-way, Husky liners, next Titan 65/35 gal tanks.
Last edited by hoseclamp; 04-25-2011 at 12:51 PM.