That's handy to know, I buy it in 20 litre drums for my car.I used to use the motul but was not happy with it (ran it in my BMW k100 for years) than switched to Penrite HPR GAS 10 10w-50 in my wee , it loves it , less engine/clutch noise and sweeter gear changes , my son also runs it in his DR650 , it loves it too same as the wee.
JUST make sure you get the GAS one the other 10w-50 Penrite oil is a car only oil it will stuff (make it slip) your clutch .
Filter changes are every THIRD oil change in the manual ,just remove the filter and drain old oil out of it. IF you clog a filter in 18,000 klm in these bikes you WILL already have a stuffed engine because it takes a LOT of missing metal from gears etc to block a filter .
I'm with you Windy, I dont care what bike (or car for that matter) it is, change the filter with the oil. Can't see the logic of putting clean oil through a dirty filter
Having changed the oil when I got my bike off dad at the 6000km mark I have decided to change it every 3000km as the oil condition was horrible. My bike has 24000klm and always been serviced by Suzuki Dealer. The oil condition might have something to do with QLD summers however???