DENIM DUDE: At 22, Zac Efron is meticulous when it comes to his clothes. Consider his raw denim jeans by G-Star, which he wore continuously over eight weeks to weather the stiff dungarees for the too-cool-for-school look, complete with dusty yellow whiskers on the front pockets. “They’re my favorite jeans,” the actor said Wednesday at the dinner G-Star threw for him at XIV to celebrate his turn as cover boy of Nylon Guys’ November issue. “I wore them all throughout ‘High School Musical 3.’ I even wore them hiking. You have to wear them everywhere to get them right.” Joined by “High School Musical” co-star Ashley Tisdale, actress Brittany Snow, local “It” girl Cory Kennedy and DJ Steve Aoki, Efron paired his dirty denim with a striped sweater by Marc Jacobs. It’s too bad he didn’t have much to say about the jeans he wore on the cover of the magazine. Instead of G-Star, they were crisp, clean Levi’s.