In a small bowl, combine the first 6 ingredients. Set aside 3/4 cup for basting. Pour remaining marinade into a shallow dish; add the steaks and turn to coat. Cover; refrigerate for at least 15 minutes.
Drain and discard marinade. Grill steaks, covered, over medium heat for 4-6 minutes on each side or until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°), basting with reserved marinade.