In Praise Of The Synthetic 5K Mile OCI In 5 QRT. Sump ?

[Malo83]

To the 3K synthetic oil changers

Glad to see many have learned nothing through the years on this forum.

Just wonderful.

Taken with a grain of salt.

 

[Quantico]

3 k changes seems wasteful. Unless its yearly. Or the first engine oil change.

 

[HiPowerShooter]

My last UOA came back with a recommendation of stretching to 7500mi, beyond my normal 5-6k OCI. I just don't know if I can bring myself to do it. The 5/6k seems to be MY personal comfort level especially in my 3.0 Duramax which is coal black in short order anyhow. It does have a 7qt sump so maybe, MAYBE I'll give it a shot considering I'll be putting about 5k on it during an extended cross country trip then send it in. I don't feel so unsettled considering all the highway miles I'll be racking up...

 

[Gene K]

My last UOA came back with a recommendation of stretching to 7500mi, beyond my normal 5-6k OCI. I just don't know if I can bring myself to do it. The 5/6k seems to be MY personal comfort level especially in my 3.0 Duramax which is coal black in short order anyhow. It does have a 7qt sump so maybe, MAYBE I'll give it a shot considering I'll be putting about 5k on it during an extended cross country trip then send it in. I don't feel so unsettled considering all the highway miles I'll be racking up...

I wouldn't pay to much attention to that. My 12.7L Series 60 Detroit will have coal black oil almost as soon as you change it.

After 40,000 mi it still has 50% of starting TBN, a tiny fraction of allowable soot and oxidation of around 12% and that's on Delvac 1300 15W-40 not a synthetic.