My wife has a 03 Mustang coupe w/ the v-6 motor. The owners manual calls for a 5-20 w. oil. This is only available from the dealer at an exorbitant price. I asked him what would happen if I used a good 10w-30 oil instead & he said you'd probably blow all the seals out of the motor. Was he just lying to me or has any one else used the cheaper oil w/ no ill effects?
Paul