I use 10w 40 in my 300. It says that right on the filler cap. For the lights, if u take off the speedo and take off the plastic cover the whole led light system on it will push out. Then im pretty sure u have to go to cat and get the replacement. They told me how to do it but i couldnt figure out what i do after i puch them out. But they replaced them. Take it apart and have a look, wont hurt anything.