Originally Posted by bismic

Another thing that would be cool to see Mark is an oil analysis at your next oil change.

Originally Posted by bismic

Thanks Mark. Could you confirm your injector life/replacement history? What caused you to change out your injectors? Also, how many miles on average between oil changes - ie OCI?

Injector life is an additional "key factor" to success, (although clearly the 460k miles is the primary achievement - and a great one).

One extra variable in the mix is the fact that the CK oils have replaced CI and CJ oils. Then you have the whole Ford approval thing to think about ........ Not much long term data comparing CK and CJ oils in a 6.0L (HEUI), so many questions can still be asked!

The intent was for the CK oils to be MORE shear stable than the previous formulations, but there are still a lot of unknowns IMO. This expected shear stability should actually improve the performance of the 5W40 oil year round, but who knows specifically with a 6.0L. I have watched for good data on this, but haven't found any - not as many 6.0L enthusiasts these days. I only have a couple of runs (5k miles each) on the new CK oil, and my oil analyses results have still been as good as the previous oil.

I am at about the same vehicle weight and driving style as you. One exception is that a lot of my miles have been with a performance tune (Gearhead SRL+). Even tuned, I have always run VERY GOOD ECT and EOT. Because of that, I have little doubt that had you closely tracked the oil temperature numbers, the 5W40 would have been shown to have essentially the same oil temperature numbers as 15W40 ...... since both are 40 weight oils.

So - sounds like you should do well with the same oil change habits that you have had in the past, but my oil change data (again - mostly on CJ oils, but several with CK oil) shows that you should also have absolutely no problems w/ a 5W40 year round. Ford warned us in the early days about the lower ambient temperature issues (injector stiction) that would exist w/ 15W40. Again, maybe some of that has changed with the CK oils, but I would still not use 15W40 oil when temperatures consistently dropped below freezing because of the injectors.

Originally Posted by mmenzies

What's the consensus on mass replacement. Just do the bad ones or go ahead and do all the others on the same side while you are in there. All 8 were replaced at 194K Miles and I am now at 310K They were ford remans from Tousley

Mark

Originally Posted by bismic

I found this post from you when you were at 310k miles and looking at injectors. Wasn't sure if you replaced them at 310k or not.

Originally Posted by mmenzies

As I say I would have to check my file which I don’t have access to right now. Maybe it was around 310K that I did the head gasket and studs (yes failure) and maybe replaced or looked at replacing injectors at that time. It will take me a couple of weeks to confirm since I am still away from home