Does Zac Efron lip sync

Zac Efron's voice was blended with Drew Seeley's voice for the character, Troy Bolton.
Troy Bolden
Definitely not, haven't you ever heard him sing before? Listen to the soundtrack of High School Musical or Hairspray
no he doesnt. he sings, but it sounds so terrible that they used different sounds to create a better voice. in real life, he sounds just awful. believe it. its the truth.
for tha'first one it was drew seeley.
Yes he does.