The thing is...that MIGHT NOT be "contamination". Pennzoil Platinum bottles have some sediment in them that might look like contamination. It's not. Those bottles should be agitated before adding to the crankcase...it's part of the anti-wear additives that have settled out.

The "proof" of "broken-in-oil" is used oil analysis done on virgin oil, compared to 1000 miles, then 3000 miles, then 5000 miles, etc., watching how wear rates per mile decrease for a substantial length of time, prior to slowly creeping upward until these wear rates equal, then exceed, the wear rates seen the first few thousand miles. No brand of oil is exactly the same as other brands, and no one car is exactly the same as another. But, the trends are similar, in that wear rates per mile start out high...gradually decrease, then, as the oil actually begins to break down or get saturated with contaminants, the wear rates per mile begin to go back up again. Bob is the Oil Guy is the best place to look for actual UOA"s that demonstrate this phenomenon.

Again, I don't think it HURTS to do all the oil changing (despite the increase wear per mile of new oil)...I just don't think it helps.

 

Well all i know is that it looked metallic and i could feel particles through my fingers at the 100 mile change. I definatly wanted that oil out of my engine.

I looked a bit over at BITOG and all i could find were people citing the Ford study or some SAE paper that was about tappets only. Testing oil in a UOA and showing a higher amount of "wear" particles on a 3K oil change and a 5K oil change don't convince me of jack. How do we know that the new oil isn't dislodging crap from the previous oil change that just would get re-suspended if you left the oil in the crankcase for a few thousand miles ?

If someone ran and engine for 100 miles and changed the oil 10x tore the engine apart after every oil change and took readings with a micrometer and then did the same test with the same engine and waited till 5K miles and the increase in wear went down i might believe it. Also you would have to do it with two engines, one starting out with the 100 mile mark and one starting out with the 5K mark for it to even be viable.

I'm just not buying it.

 

changing oil imo should be done on mileage, hours and conditions. If your riding on the road, lower rpm ( not trying to do 70mph) I think 1500 miles would be ok. If you are running tight single track in an enduro- in 90+ degrees with dusty condition, I change it at the end of the day (80-100 miles). for every thing else somewhere in between.

I look at it like cheap insurance to make a motor last. It also is a way to see in the inside of the motor by looking at the oil.

 

Actually, you'd need a series of engines, and have the results verfied by another independent person doing the same tests in the same manner in order for it to be considered "scientifically proven".

You'll have to wade through the 100,000's of thousands of UOA's, OR, take the word of some of those that have actually done the testing as Tribologists (it usually doesn't take long to figure out who those scientists are).

Like I said, I don't think it's hurting the engine to do what you're suggesting. But, like you, I just don't buy it that it's really making a positive difference in performance or longevity....too many examples of people NOT doing what you're suggesting, and having great running and long lasting engines. Plus, there's what some scientists (that do this for a living) are saying about oil taking a while before it functions at it's "best".

I choose to go by the most current science. Others choose to go by feel or belief. Doesn't make either one of us "right" and the other "wrong". Obviously, either way works well enough for most people.

 

Why not take a further step and actually test that oil, rather than depending upon sight, feel, smell, and taste? You do taste it, don't you? (Everyone should know not to do that...just trying to be funny....it is poisionous and considered to be carcinogenic.) You might be surprised at what you find. If you find the same things I did, you'll likely quit changing it as often. Situations can be different though, so, what I find may not be what you find.

Just in case anyone is interested, what I found (by spending the time and money, and using an actual Tribologist for analysis) is that the oil is much cleaner than I would have guessed, but, in the three wet-clutch shared transmission motorcycles I tested (which did NOT include my 09KLX250), the viscosity is what takes a big hit. In order to (mainly) protect the transmission, the oil needs to be changed about the time shift quality begins to change...that seems to correlate accurately with a significant decrease in viscosity as observed by UOA. This has never made perfect sense to me, as motorcycle transmissions are in constant engagement...every gear is turning all the time. Yet, it certainly is true....it can be felt, or, at least detected by shift quality.

One person's experience doesn't mean anything. Study serial UOA's by loads of different people...most all finding the same trends, and it the evidence mounts up. Or, don't worry about it, and just keep changing the oil and filters as often as you feel necessary...it's not going to hurt the engine...as I've said over and over.

 

I'm changing oil every 1000 miles or so, did the Mototune break in November 05 and I just hit 14,400 miles. It purs like a kitten, especially since I just did the manual adjust on the cam chain adjuster.

 

Wow, all this and my only question was "when would you change the oil next"

Oh how I love internet forums..

 

hahaha, have you changed your oil yet?

 

Changed it at 20, put another 30 on last night. Maybe I'll wait
until 75 or 100 for the next then 250 or so.