So I made a thread about this awhile ago
Heres the backstory I bought an 06 is350 2 years ago and the PO told us that the vehicle sat for a year since they never used it much. So I monitered the oil for the car (99k when bought 126k right now), and the first 3 or 4 oil changes the oil was at or near the bottom level on the dipstick and...
bobistheoilguy.com
After 6+ oci with a synthetic oil I stopped burning oil. First thing I noticed while driving conservatively the most part for the first two oci (3500 max rpms but mostly 2100) and loosing over 1 quart during those first two 5k oci I decided to change my driving style. Afterwards I drove more aggressively rpm wise and not too much in the speed range (its why im still alive typing this for you
) this somehow cleaned up my potentially stuck rings which made me think that the previous owners babied it and drove it conservatively too much so that didnt help with the faulty piston ring design, so the high rpms help with these "older" v6 toyota engines with piston ring issues and especially if babied and not wrung out every so often. The synthetic oil I used was pp/pup due to their gtl claims, and am quite happy with the results, it was quite dark for the first 3 oci where it may have cleaned the old excess oil that was in the system and potential piston ring junk, I am not a pennzoil loyalist either since I still use mobil and other oils (castrol, oriellys etc) for different vehicles. I dont claim this will automatically fix your oil burning issue for your engine (could be leaks or more serious problems), but in my rare case it did. Would using another oil work I think so but the gtl did show color differences that wouldnt be possible with other brands, and the lighter it got the less oil it used. I know the higher heat caused by the rpms removed junk within the rings and engine overall, and I also drive long distances so oil always warms up so no short trips. I also wanted to thank everyone who posted on my old thread and taught me how to better monitor the oil and what I could change, super thankful for all of you!