It is the water temp gadge.... defo no oil... and the advice not to gun her till its above the lines is what i do too, as for oil the thin oil as in 5w is the stuff you want, if you have a tdi or a higher milage motor then semi syn is prob the best stuff, its a little thicker, i user castrol RS in my wagon, but magnatex is the stuff i will start using once the milage starts to rise abit.