'00 996 got it at 1400 miles old, oil changed every 2500 miles, none required in 15000 miles of ownership.
'02 998 is now 7000 miles old and has never needed any, oil every 2500 miles.
'9? 748SP track bike, history not known, checked at Nellys and needed one immediately and three others will need to be replaced at next big service as they are bruised.
Always run Shell Advance 15/50 in the 996 and 998 but am using Motul 300V fully-synth 15/50 in the 748 as it was the only one in the local bike shop with 15/50 rating.
Just changing it at the moment as I am trying to cure an oil leak
but hope to do it after every two trackdays anyway.
Never rev the bike too hard until the dial started to move on the temp guage though, pedantic but its seen me well with the 996 and 998.