It is also corrected in the 2005 owner's manualted clement said:Bendi, you are correct that 10-40 motor oil is used for the 400 gear oil. There was a misprint in the owners handbook that came with the 2004 model which Suzuki corrected by sending each owner a sticker to place over that page. Apparently your dealer/agent has not got the word or doesn't have the service manual which correctly states 10-40.