I run it in summer. Also run their gear oil too..only switched to Delvac this time around, bc ofctheir ridiculous offer rebate good til dec 31

 

Was looking at Delvac yesterday. Still CJ-4 too. Good stuff!!

 

Read the bottles. I've been a Delvac guy for the last 10 years and I bought up as much CJ-4 as my wife would let me when they started switching over. Most of the Delvac I see now (O'Reilly and Wal-Mart) are CK-4 and not on Ford's "approved" list.

I just used up the last of my stockpile this last change and am thinking of going Supertech the next round in a few months.

 

I did. The ones I saw at a ranch store yesterday were still CJ-4. Maybe leftovers? My truck didn't like the CK-4 crapola.

Make the switch!! You'll he happy I think.

 

if you have a local heavy equipment dealer like Cat or such they sell UOA kits for like 14 bucks and includes TBN if you ask. my local guys https://www.gregorypoole.com/service...luid-analysis/ provide a good service for less than blackstone.

 

So rotella moved to the ck-4 and then Delo was a little behind which I was using their CJ-4 5w40 because it had the correct phosphorous content, but now they have the ck-4. It's tough to find it locally. My truck didn't seem to mind the ck-4 though.