Originally Posted by MaximusPrime

I have almost 58,000KM on my bike.
I changed the oil at 300, 600, 1000, and then 1500-5000 miles there after (depending on how the bike was ridden and the season - less oil changes in winter(it's cold out!) ). And that is all year round riding (-20ºF - 100ºF) in every type of weather (I should work for USPS).
Until this past summer I used Castrol 10W-40, then switched to Rotella 15W-40.
Thus the start of this thread...
Now running the synthetic Rotella 5W-40.
It has definitely let me start the bike when it and the air temperature is 10ºF! It also runs better in the cold.
If it get's colder than that, I ride it up a ramp, onto my porch, and into my front room (which is unheated, but it helps).
Only mods until this fall were a 300 muffler/header and A/F screw out to get best idle.
I added a better air filter and DJ kit this fall. Runs like a raped ape but the MPG is way down (60mpg - 40+mpg). It couldn't be that I'm enjoying the extra available power, nah...passing with a 6th gear roll on the throttle.

All riding miles were mostly a 40-60 minute, 24 mile, one way commute, but there are also thousands of miles of trail riding and long distance highway riding at WOT. Almost every time the bike starts it is ridden and for long enough not to worry about acidic oil.

P.S. - Oddly enough, I don't get the header glow after jetting. I suspect when I tear down the engine there won't be a ton of carbon buildup thanks to the hot lean condition of the stock motor. Not that that helps my current set of rings or valve seals. We'll see this spring when I can get the Duc back on the street (snore. Totally sold on the slow bike fast over the fast bike slow debate) and give the KLX some down time for a strip down and refresh.