This question is mostly for Road Rage, since I know his background and trust his opinion.


So, why 3 months between oil changes? (I understand that formulations change this, but why is there a time limit at all?)

I can only assume there is a reason (suspension of additives, etc) for a 3 month interval, but what if you don't have to work every day and put less than 3000 miles over 3months? Maybe you do drive at least a couple times a week, but not every day?

 

i looked into the oil journals. came across this thread. might have some insight into your question.

https://www.s2ki.com/forums/index.php?act=S...=0#entry4205938

 

Maybe, the suspension may be the issue, that's what I'm trying to ascertain for sure.

 

Conventional oil lasts ~6 months and synthetic will be good for a whole year.

 

Ok, and the whys?

 

3 month interval's are a thing of the past. (60's and 70's)

 

Again, not what, but why.

 

Check out the oil journals. I am pretty sure its in there...I am almost positive I read this in there about 2 weeks ago. There is a complete write up on how changing oil every 3 / 3,000 is archaic and not needed anymore with current syns.

John

 

Ok, they always revolve around the 3000 mile intervals. I'm curious about the chemical reasons behind the 3 months. Ok, this has nothing to do with whether you should, or if 3000 miles is required or anything. What is the reson for oils originally being replaced every 3 months if you don't put 3000 miles on it over 3 months.

 

because oil will break down over time as well as with use. so if the oil sits for long enough, it becomes ineffective at doing its job.

the 3 month/3000 mile mantra came from back in the 60's/70's when oil was nowhere near the quality it is today.