Altima brakes are bigger and 4 lug. A couple other nissans use 2 piston calipars and are 4 lug. But just redrill the 5lug rotors to 4lug. its not unsafe aslong as you spread them out. And plus you will love the way z brakes fill. I have z brakes on my car, its 4lug. locking the fronts up at 40mph= bad ass.