 The modernized A-4SU and TA-4SU versions with its new F404 turbofan engine had 29% more thrust, which resulted in a 30% reduction in takeoff time as well as an increase in usable payload, range and maximum speed.The maximum speed now at sea level is , and maximum cruise speed at is .By 1974, the RSAF received enough refurbished A-4S to form the No.