What's the best motor oil for 1997 M3 during a hot summer????

i always say any oil with the api logo on it,just make sure its not emptyWhat's the best motor oil for 1997 M3 during a hot summer????
amsoil is probably the best Ive used. but its EXPENSIVE. but hell u drive an m3What's the best motor oil for 1997 M3 during a hot summer????
THE Best would Synthetic. Either Mobil1 or Valvoline.








Good Luck...