Knowing When to Shift Up. There are two ways of knowing when to shift Use Engine Speed (rpm. Study the driver's manual for your vehicle and learn the operating rpm range. Watch your tachometer, and shift up when your engine reaches the top of the range. Some newer vehicles use "progressive" shifting the rpm at which you shift becomes higher as you move up in the gears. Find out what's right for the vehicle you will operate) Use Road Speed (mph.Learn what speeds each gear is good for. Then, by using the speedometer, you'll know when to shift up. With either method, you may learn to use engine sounds to know when to shift.