Since you asked... There is a boat load of them (pun intended).
Conventional Lubricants: Motorcraft Super Duty 15W-40 or 10W-30 Penzoil Long-Life 10W-30, 15W40 Shell Rotella-T 15W-40 Chevron Delo 400 15W-40, 10W-30 Mobil Delvac 1300 Super 15W-40 Valvoline/Cummins Premium Blue 15W-40 Union 76 Guardol QLT 15W-40 Union 76 T5X Heavy Duty 15W-40 Kendall Super-D 3 15W-40, 10W-30 Quaker State FCI HDX Plus 15W-40 Exxon XD-3 Extra 15W-40 Phillips 66 Super HD II 15W-40 Conoco HD Fleet Supreme 15W-40, 10W-30 Citgo Mystik Premium Fleet 15W-40 Citgo Mystik JT-8 15W-40, 15W-50, 10W-30 Castrol GTX Diesel 15W-40
Synthetics: Amsoil 15W-40 Synthetic Blend Oil Chevron Delo 400 Synthetic 0W-30 or 5W-40 Mobil 1 Turbo Diesel Truck Oil 5W-40 Synthetic Mobil Delvac 1 ESP5W-40 Synthetic Motorcraft Super Duty 5W-40 Synthetic Valvoline Premium Blue Extreme 5W-40 Synthetic Shell Rotella T 5W-40 Schaeffer's Supreme 7000 Synthetic Blend 15W-40 Schaeffer's Supreme 9000 Synthetic 5W-40 Kendall SHP Diesel (synthetic blend) 15W-40 Petro-Canada Duron XL 15W-40 Synthetic Blend Royal Purple Synthetic 15W-40 Citgo Mystik SX-8 15W-40 Synthetic Blend Advantage Duragard Super HD 15W-40 Ford is recommending to use the following oils for the listed operating temperature: SAE 15W-40 is the preferred oil above 30 degrees, but it is acceptable for use down to 10 degrees, and is recommended for towing down to this temperature. SAE 10W-30 is the preferred weight between -10 to 30 degrees. SAE 5W-30 and 5W-40 is acceptable for use below 30 degrees, and 0W-30 is acceptable below zero. (All temperatures are in Fahrenheit)
Most (not all) of the above info is from BITOG which is an excellent source of oil info
FWIW Many 6.0 owners run 5W-40 synthetic year round with great results-
I've done UOA (used oil analysis) on my 6.0 for almost 4 years now. I've used Rotella 15w-40, Rotella 5w-40 and Mobil 1 5w-40. The Mobil gave me the best results, less shear being the most noticable quality. Downside to the Mobil- price, $22 per gallon.
I'm going Rotella Syn 5w40 on my next change. Maybe if I want to spend the extra money I'll eventually go Mobile. My dad has the same engine and we've discussed buying Mobile by the 55 gallon drum, but he does a lot of heavy towing so I think he should stick with a 15w-40. Maybe I'll still buy a drum though, 55 gallons is only 15 oil changes
ive been running rottela 15w-40 in the late spring threw the late fall.And run rottela 5w-40 syn from the late fall to late spring.I will be looking into staying with a syn oil threw out the year.Starting this year.iam thinking about royal purple or Lucas oil.
But rottela 15w-40 and 5w-40 syn has been good to me for almost 5 years and over 100,000 miles