The type of oil is most important. I use Mobil1 in my bikes and change it (and the filter) when it gets dirty. Usually around 4K miles. I've got 74K on my '91 GSX1100G and it still doesn't use any more oil than it did when it had 6K on it. The seals haven't had to be replaced either.
BTW, it can't hurt to change oil more often than the recommended interval. Frequent changes are relatively cheap insurance. I know some of the new bikes have longer intervals, but they make me nervous. I'm going to stick with what I know works for me.
I have gone to changing 6000 miles after starting to use Amsoil synthetic. The MOM states 7500, but I like nice even numbers. I have read that 18 wheelers will run 100,000 miles on good oil (such as Shell Rotella Synthetic) with just a filter change. Have never talk personally to a trucker about that though.
Congrats Longride! I wish my Ravens were meeting you but they laid down against the Doga-- Colts. Normally I would be rooting for the AFC but since the Doga-- Colts are in the game,I'll be rooting for your Bears. Jim Irsay can kiss my a-- !Unfortunately I think the Doga-- Colts will win,but I hope not! Enjoy it LR,its been awhile for the Bears.
I use Mobil One synthetic in the spring, with a new filter.
In the winter, before lay-up, I use cheap dino-juice with no filter change - I've read that you shouldn't leave old oil in the crankcase while it's laid up. The dino-juice is purely for sitting in the engine through the winter. In the spring, the dino comes out and the good stuff goes in with a new filter. And the Cycle of Life continues.
Now I'm sure that I'll have someone tell me that I'm contaminating the synthetic with the remains of the dino and will chew my Johnson Rod all to hell.
I hate to get off our favorite sport ofsquid bashing, but I think every 2500 miles is about right. A mechanic whose judgement I trust thinks you can safely go twice as far on synthetics, which is only fair, since they cost about four times as much. Whatever you use, be sure it's formulated for motorcycles. I used regular engine oil (20-50 here in California) for many years, but I'm told the clutch, which runs in an oil bath, needs slightly different properties, and the oil in a motorcycle also is subjected to greater shear type of stresses in the gearbox than would be encountered in a car engine. Now, back to disrespecting that idiotic squid.
Between this topic and the engine break-in thing, we tend to get so ridiculously anal and verbal. Everyone has an opinion and their's is the only right one. I certainly am not suggesting that anyone should over extend changing their oil and filter changes or bashing the hell out of it's engine during break-in, but I really feel a well built motorcycle is a lot less sensitive and far more durable than we give them credit for. I have this sneaky feeling that a lot motorcycles all sit around and laugh their a-s-s-e-s off at all of the commotion and useless discussions us humans create concerning these two topics. For the record, I used Amsoil synthetic for years. Awhile ago, they had a big price increase and Kawasaki had a terrific promo on their 10-40W motorcycle oil. Have used that in my '06 Gixxer Thou' since birth. I change it every 3000-3500 miles along with the filter. I also had it completely broken in and up to redline in 50-60 miles. The technique I used was not at all abusive and is very specific to proper engine break-in. This is the first time I used this method, and it sure worked beautifully. It doesn't burn a drop of oil and scoots down the road just like a well kept Gixxer 1000 should. For those that are interested, I used Evan Brasfield's break-in procedure found on page 204 of his book, "101 Sportbike Performance Projects." ISBN # is 0-7603-1331-8. Amazon.com sells it for $19.77 plus shipping. I've been riding for 43+ years and have always done my own maintenance, including building my race bike's motor and chassis. I found this book was a valuable addition to my motorcycle library.