It is my understanding that CJ-4 is ok, but not CK-4

 

What if it has BOTH on it?

 

If only CJ-4 appears under API service and CK-4 is NOT present, it is ok to use. If CK-4 appears on the API service, that oil needs to be on the latest Ford approval list, that F-350 posted earlier, before that brand can be used safely.

 

The claim is that CK is backwards compatible, so the argument can be made that any CK oil is safe for CJ rated engines. Not so according to Ford. Smart advice is to ignore the label and choose an oil on Ford's approved list.

 

Yeah, it looks like Ford and the EPA changes to the oil have really made a mess of things

Thanks all for the info

When my new (rebuilt) injectors arrive, what would YOU run?

 

Ask me next week. I've sent off a sample of the Valvoline heavy duty to blackstone and am currently awaiting results. I may or may not change my opinion once I receive the results.

 

That would be excellent timing, thanks!

 

So, what changed with the older oils? I have been using either Rotella T or Mobil Delvac 5-40 for years with great Blackstone reports. I have seen a lot of mention of but haven't seen why the CK designation is bad?

Thanks.

 

Because to meet the new CK rating, they had to pull more good stuff out of the oil so it doesn't lubricate as well as it used to, but it does help with emissions.

Walking helps with emissions too, which is what Ford is hinting we might be doing if we start using a non-approved CK oil.

 

Can't wait to hear your results!

 

So, should I be worried that my last oil change with Shell Rotella T6 isn't on the approved list? What should I change to? Should I shorten my change interval and get it out of there?

 

Nope, you should not be worried at all about T6.

 

Thanks Chris. Crap this is confusing. Most of the recommended oils are 15-40, not much out there in the 5-40 range. Plus this seems to start with the 6.7s? Talk about tighter clearances, etc. Might just stay status quo, shorten my change interval and ship off to Blackstone sooner rather than later. At least until my injectors die, then "honey, I have to replace them"!!

 

I used Delo for 16 years and refuse to use it till it makes the list. Went with Valvoline HD this time under F-350's recommendation. If he has 600k on a 7.3 his word is gold.

 

Me too. Not a peep from Blackstone yet, but they haven't charged my card yet either, so maybe they're just behind. Or the sample got lost in the mail.