Pennzoil Ultra 5W30, 6250 Miles, 09 Infiniti G37

[Sunstealer]

I am working my way up to the maximum Infiniti interval of 7500 miles. I went 6250 this change (longer than planned due to some family emergencies over the last few months.) It looks like it went fine though, other than viscosity dropping again, but not as much as it did at 4000 miles. My wife was the primary driver for this change though, and she is more conservative than me.

 

[ltslimjim]

I've heard that if allowed to build deposits, even though the oil may be okay for continued use per se, without changing the oil prior to this happening it can cause certain issues in these engines(valve train perhaps). Maybe someone else knows the particulars and what I may be alluding to?

Not sure what exactly in a UOA you could get, aside from ISO code? to check for how clean the oil appears?

Then again, I could be totally off base here. It looks like a decent report, otherwise.

 

[Steve S]

What is the non severe oil change interval on the vehicle?

 

[Sunstealer]

3750 severe, 7500 max intervals. My wife is in sales, so she does lots of highway driving.

 

[OldCowboy]

I wouldn't try to push it past 7500 miles. At 6250, you've already exhausted 73.5% of the starting TBN. I do not agree with Blackstone's statement that anything above 1% is OK. I think when you get to 80% depletion, it's time to change oil.

 

[gib]

Originally Posted By: OldCowboy
I do not agree with Blackstone's statement that anything above 1% is OK.
It's just 1, not 1%. I don't think anyone would claim running the TBN down to 1% would be acceptable.

 

[bodeh6]

It thinned out quite a bit. I wouldn't really run it longer.

 

[OldCowboy]

Yep. I meant TBN of 1 not TBN of 1%.

 

[Brons2]

I wonder what the universal averages are based on? The report looks good compared to those.

I think a 5w40 or 0w40 might be better in this engine from a shear standpoint, in my experience Nissan engines like a heavy 30wt.