I have used Lucas Oil Products in all my vehicles. Just sold my 97 F-150 which had 270,000 miles on it. Never used oil between oil changes, never had a problem with differentials except a rusted out rear cover. I always put the modifier in, just because. I guess it is personal preference on which oil you use, but I would have to say they are all pretty good.

 

I got a 2007 f150 king ranch 4x4 super crew and I wanna know is rp 75w-140 the recommended oil for the rear end?

 

Somebody's full synthetic 75W140 is the recommended fluid. If it has limited slip, you also need friction modifier.

 

been using all royal purple since first came out in 2003. never needed any engine jobs transmission or diffs since i put on 100k miles a year.
see info at http://www.royalpurple.com/company-history/

ROYAL PURPLE HAS A FRICTION MODIFIER NEVER ADD ANYTHING ELSE EVER !!!!

Max Gear – High Performance Gear Oil

Max Gear is recommended for use in truck and automotive front or rear differentials, manual transmissions and lower gear units of marine engines that specify use of an API GL-5 or GL-4 fluid. It is non-corrosive to soft yellow metals (brass, bronze, copper, etc.) and synchronizer safe

Max Gear is an ultra-tough, high performance automotive gear oil designed to provide maximum protection to heavily loaded gears while maximizing power throughout the drive train. Max Gear outperforms ordinary gear oils by combining the highest quality synthetic oils with Royal Purple’s proprietary Synerlec additive technology. Max Gear makes gears run smoother, quieter, cooler and longer without overhauls. Max Gear is formulated with a friction modifier additive – no additional additives are necessary.

Max Gear is available in the following viscosities: 75W-90, 75W-140, 80W-90, 85W-140 and SAE 90

Royal Purple API-licensed Motor Oil

Royal Purple’s API-licensed Motor Oil combines premium base oils with proprietary additive technologies to create high performance motor oils that optimize engine performance. Royal Purple’s API-licensed motor oil delivers superior protection and improves performance in gasoline and diesel engines. Royal Purple’s API-licensed SN motor oil meets ILSAC GF-5 and Dexos1™* performance requirements.

No special procedures are necessary when upgrading to Royal Purple. Royal Purple recommends waiting until the manufacturer’s first scheduled oil change in new gasoline and diesel engines before upgrading to Royal Purple.

Royal Purple motor oil is compatible with synthetic and conventional motor oils. Available viscosities include: 0W-20, 0W-40, 5W-20, 5W-30, 5W-40, 10W-30, 10W-40, 15W-40 and 20W-50 weights. Royal Purple also offers mono-grade motor oils in SAE 30, SAE 40 and SAE 50 weights.

 

Hi I have changed my frontdiff, rear diff, transfer case and engine to royal purple. I seemed to gain a couple mpg after the change, and i only had 86000km on original oils.

 

Royal purple is a ok synthetic oil in a application like a pick up truck pretty much any synthetic will be fine. In a extreme, demanding application I have found the R/P to be not up to task and there a better choices out there, Smitty