How to differ standard-efficiency, high-efficiency, and NEMA Premium motors?

Motors that meet EPAct standards have lower losses than the old "standard-efficiency" motors they replaced, and NEMA Premium motors have still lower losses. NEMA Premium motors are motors that go a step beyond EPAct. NEMA Premium applies to single-speed, polyphase, 1 to 500 hp, two-, four-, and six-pole (3,600, 1,800, and 1,200 rpm) squirrel cage induction motors, NEMA Designs A or B, 600 V or less, (5 kV or less for medium voltage motors), and continuous rated. The designation does not apply to fractional horsepower motors. Please note that NEMA Premium motors may have different speed, torque, or other characteristics from those EPAct-level motors they replace. It's important to take all engineering parameters into account..