Bests & Worsts Reviews from Amazon

Bottom line: I have documented 50-55% reduced wear through used oil lab analysis (Blackstone) and it is mandatory in all my Diesel (truck, boat), Gasoline (daily drivers, weekend sports car) applications; also add 2 oz to power steering reservoir – much smoother and gone is the “loss of power steering” symptom in tight parking maneuvers with oversize (37x13.50x20) tires. On my 2006 F-350 6.0L (owned since new) I switched to synthetic 5w-40 (which Ford recommends for Severe Service, All Temp ranges per manual) - personally I used Mobil 1 then Shell Rotella T-6, mine ran smoother on the Rotalla. My 6.0L started much better with the 5w-40 synthetic due to faster cold weather flow and the AR9100 made a big difference - mine used to run slightly rough below 30* and didn't feel like it had full power until it warmed a bit after 5-10 minutes of driving - that "hesitation" (for lack of a better term) was cured by AR9100; the 5w-40 alone did not fix it. I personally never exceed 5,000 miles drain interval regardless of weather, usage (towing, highway, stop and go) and use 16 oz of AR9100 at every oil change (keep a 1 qt bottle and use ½ oil, then add 16 oz of AR9100 during refill instead of the last ½ quart of oil so you do not overfill). Remember HEUI injectors (hydraulically actuated electronic unit injector) in the 7.3L, 6.0L motors were developed by and licensed from Caterpillar and are driven by oil pressure and that is where stiction (any amount of oil sludge will cause it) comes in. Archoil has a money back guarantee – if it does not fix stiction, you get 100% refund but you likely need new injectors. Be sure to use **CJ-4** oil; there is a new "CK-4" formulation since December 2016 demanded by the EPA which reduces zinc, phosphorus and viscosity - Ford issued a TSB and “CK-4” is NOT APPROVED BY FORD FOR ANY FORD DEISEL (Ford has a new Ford Material Engineering Specification WSS-M2C171-F1 (Google it) and Cummins issued CES20086 which several enhanced CK-4 oils are meeting but I would stay with CJ-4 while available) because of increased wear. Noteworthy is the “CK-4” diesel specification removed the valvetrain wear test (ASTM-IIIG) used on all previous diesel specifications, like the CJ-4 diesel oil spec. And yes Powerstroke haters increased wear will affect ALL DIESELS - Cummins, Duramax, Navistar, Caterpillar, Mack, Detroit Diesel, Mercedes-Benz etc....I guess the other brands (excluding Cummins) want you to buy a new truck sooner so have not opposed CK-4 - all the more reason to use AR9100 as CJ-4 is now harder to find. To monitor the benefit of AR9100, I use Blackstone Labs (there are many labs to choose from) to perform used oil analysis - the labs give you a wear benchmark across the thousands of samples for your specific motor (they do this for gasoline engines as well if that is your application) so you have an index for the critical wear (iron, aluminum, copper - the reports explain where the wear is indicated based on metal type - bearings, pistons, block, cams/rocker arms etc), also silicone content will tell you the effectiveness of your air filter, coolant indicates head gasket or oil cooler issues, too much fuel dissolved in oil is an injector issue or way too much idling - well worth $30 in my opinion. With full synthetic 5w-40 and the Archoil AR9100 in my 6.0L, my wear metals per lab results were approx. 60-65% less than the average for the motor. I now have a 2014 F-350 6.7L I bought new and am also using the same oil / AR9100. In my 6.7L I am observing wear that is 50-55% less than the index. Prior to trying AR9100 and only using synthetic oil I was observing 10-15% less wear than the index. I am a believer. Hope this helps.