The attached photo is the latest version of the product label and remains a CJ-4/SN made by Warren as distributed here in Coastal GA at Walmart as of 10-04-18.
I will write to Warren and ask them if they plan to maintain the SN for the gasoline mixed fleet community which will require them under the CK-4 pretense to reduce zinc dialkyldithiophosphates or drop SN and provide a path to adding Ford WSS-M2C171-F1 to the label.
The trade study comparing volume of sales to diesel/gasoline mixed fleet customers who rely on the "/SN" suffix historically as compared to the projected sales to customers who are knowledgeable about ZDDP reduction and side with Ford on WSS-M2C171-F1 is difficult in a corporate environment as putting hard numbers on projected sales is more difficult than historic sales. The majority of oil companies have maintained SN to-date due to the investment already made in the past to add that compatibility and a reluctance to discard that investment as a trade off to become compliant with Ron Romano's mandate for zinc dialkyldithiophosphates, the Ford Lubricants division head.
Reference Ron's slides presented to the HDEOCP (Heavy Duty Engine Oil Classification Panel) beginning on Page 81:
The photos (attached here for your convenience) show the unacceptable wear to the rocker arm fulcrum resulting from endurance tests in a 6.7L PSD with 10Wâ€30 PCâ€11A formulation.
Note that any references to PC-11A (Proposed Category 11A) is simply the developmental name for CK-4.
http://www.astmtmc.cmu.edu/ftp/docs...utes%2020161206%20with%20attachments.pdf
Note that the above was presented to the HDEOCP which is an ASTM organization lead by senior staff engineer Shawn Whitacre of Chevron appointed in 2015 who replaced Jim McGeehan who held the role since 1987. The Chevron Delo oils maintain the SN. Dan Arcy was present from Shell. Shell Rotella offers variants of CK-4 oils that drop the SN category in favor of maintaining higher zinc dialkyldithiophosphates levels and providing a viable candidate for Ford WSS-M2C171-F1.
My recommendation to Walmart, Warren, Safety Kleen and others: Drop the SN during your transition to CK-4 oils as sales volume will go up as your resellers' pricing itself is the main driver for sales coupled with OEM compatibility listings on the label. Volume will increase going forward as more customers become educated to look for the Ford WSS-M2C171-F1 and you will still retain your mixed fleet customers since you provide the lowest cost-per-gallon oil. Customers will not change brands to a higher cost per gallon oil manufacturer simply to standardize their gas/diesel oil inventory for each API weight as long as you develop marketing material to educate the customer that you provide 100% compatible, lowest cost oil.
Since we already know the results of CK-4/SN on the 6.7, I have decided to perform a test using Chevron Delo 400 XLE 15W-40 in my International Navistar 7.3 with 270,000 miles and will submit for UOA and compare that to a UOA of Traveller (Warren) CK-4 (Non-SN) 15W-40 from Tractor Supply.
- Another shade tree mechanic hoping the oil companies will listen.
