I really hate to repeat myself… No wait I really don’t. I just did.
However, if the oil change schedule that was being followed has worked this well then why the heck are people trying to rock the boat and change it?
Operating a car the way this one has been operated is beyond the abuse leading to Severe Service recommendations, in my opinion.
However, the proof is in the pudding! Not much to see here.
Waiter! Check please! Next!
CSA 
Hi guys, I been away from the computer for a while but I want to thank everyone for all the good advise, you guys are great. I am hoping we can hang on to my mom’s car for as long as possible because there is no way right now we could afford another one. So God willing this one will last or…may be I could win the lotto or become a famous artist but until then this is our car. God bless
I agree with the idea that the regular mechanic knows more about the car than anyone else. If this were my car I would change the oil every six months as well. My lady and I got her grandmother’s 1998 Camry with only 66k miles on it. It had a lot of gunk built up in the motor because it was short tripped the car’s whole life. After about 1400 miles of us having it the oil turned black in a very sudden way. I would hypothesize that enough longer runs with enough heat put in the motor caused a lot of the gunk finally released from the internals of the motor. It has never done that since. The oil only slowly gains color over time. Something to be said about those late 90s Toyotas. Great cars built to last.
“Great cars built to last.”
I hate to rain on your parade, but in case other folks read this discussion I have to bring attention to the Toyota engine sludging problems that resulted in a class-action lawsuit, brought by customers who apparently felt their cars weren’t built to last, and the Toyota settlement that followed.
CSA
Hate to break it to you… But my step father has 310k miles on his 95 Toyota Avalon. Original motor and transmission in it… And the sludge problems… Many were the V6s the generation after his Avalon was manufactured . I suggest you look around and see how many of those Toyotas are still on the road. There are several in my apartment area alone in a very nice area of town Including my lady’s Camry. Not a coincidence.
Yes there were big problems with the V6s especially. The motor in my lady’s 98 Camry is the 2.2 L 4 cylinder. Well it has only a 3.6 qt capacity to begin with. And that is a small amount. Add to that API SJ oil which had a NOACK volatility of 23%… Then API SL which had lower NOACK volatility but still higher than the current API SN limit if 15%. Add to that clueless people not even checking their oil… And then running it for too long aka 5k plus maybe even 10k miles… And wow… You have sludge?? Not surprising at all. Maybe just maybe the owners were the problem more than the motors in those cars.
Good, bad or indifferent the truth is likely that those clueless people did not take care of their cars the way they needed to be to begin with. It is still impressive how many mid to late 90s Toyotas are still on the road. And that is a fact. Similar to the Hondas of the early 90s. There were many of them still on the roads 15 yrs plus after they were built. Why?? Because those cars were pretty good too.
With high quality oil, I bet you could go 12 months or. I would definitely check the fluid every time you get gas or another interval. Maybe it should be driven out on the highway at higher speeds to get some carbon out.