i always change washers(and usually use OEM washers when i can)on drain plugs that have them, when doing an oil change. I have to do an oil change on a 2007 4 cyl Camry tomorrow, it specs 18 ft lbs on the plug. I dont have any oem washers, so i stopped at O Reillys and bought some M12 flat copper washers. Nissan and Toyota both use M12-1.25 drain plugs. I do have some oem nissan crush washers, so would it be better to use the nissan washers or the flat washers from o reillys, and should the nissan washers work good on the toyota plug, will they work as intended when torqued to 18 ft lbs instead of the usual nissan spec of 22-29? sorry for being paranoid, I just dont want the car to have an oil leak.