I have Motul 5100 15w-50 in right now. Synthetic blend. Maybe I'll go with the 10w-40 stuff next change....Doesn't get too cold here in Austin, TX.

It looks yucky black in the window...maybe I'll change it this weekend.

I run the same oil and yes it is just automotive oil, but there have been plenty
of tests done regarding the diff between motorcycle oil and conventional automotive oil and Mobil 1 syn out-performed any motorcycle oil they tested

This is the stuff thats pretty popular here in NZ and the one I use. NZ$15 per 1.5lt (US$10.25)

CASTROL ACTIV 4T

Continuous protection - Mineral based four-stroke engine oil. Synthetic ester clings to engines surfaces providing a protective film that dramatically reduces engine wear during start-up and warm-up, helping to extend the life of your engine. Leading to excellent engine cleanliness and improved oil consumption control. Suitable for all makes of four-stoke, air or water cooled bikes running on leader or unleaded fuel.
SAE 15W-50, API SG. Product exceeds JASO MA.

I think you'll find that oil isn't really suited to wet clutch application. Cars don't have wet clutch's. The JASO standard is what to look for.
Took this from a discussion on oils on the DirtRider.net site.

"One thing that may be helpful from the JASO standards is the frictional characteristics of the oil. This is an indicator of how well the oil will perform in the wet clutch assembly that most all dirt bikes have. The same oil that lubricated the engine parts also lubricates and cools the clutch, and controls how the clutch acts.
It was seen in earlier years that some inferior oils could actually cause a clutch to slip, or could allow pitting of the gears, and this is precisely why the JASO certification came to be. It was to allow the consuming public an easy way to shop for an oil that would not cause the clutch to slip and was good enough to not cause pitting of the metal gears.
There is absolutely nothing else that JASO certification tells us."

Mobil 1 4T 20/50W..

+1. Ideally you don't want any 'friction modifiers' in motorcycle oil for proper operation of a wet clutch. JASO rating is a good thing.

Passenger car oils contain friction modifiers for increased fuel economy and lower emissions...but they also have a dry clutch. A few of the big bikes have dry clutches, but I doubt you'll find any DS thumpers with them. :D

Get that crap out of there quick and put something JASO in it. Why on earth would you take a chance on car oil ruining your KLX? This oil topic always gets my blood boiling and no offense but it's because of the blatant ignorance for simple physics. The Oil is different for a very specific reason.

I use the Shell Rotella T in all my bikes. I've used both the standard and the synthetic. I hear the standard has better wear properties, but I don't know much about it. If you change it every 3K, or so, I don't think it matters much (Yes, I may change it more often on the little single cylinder.). As long as it's the right spec. oil...

I am going to have to admit my own noobishness here. I was running regular Mobil1 up until an hour ago. Fortunately I'd just changed my oil ~60 miles ago so hopefully no harm done. :o

I was out and about so I did pick up some Valvoline 10W40 4-Stroke motorcycle oil to try for now. I'll look for Mobil1 4T for the next time.

I didn't know about the wet clutch thing- but that's why I joined this board when I got my KLX a couple months ago. Thanks for the info! I'm learning. :)

Nothing wrong with the valvoline I've had the motor torn down alot and looks good I'm sticking with that and its cheap.