I generally mow around 2200 rpm, even though 2700 is the rated rpm for the 540 pto rpm. It depends on what you are cutting, how good the hog is cutting and your ground speed. Right or wrong, that's how I do it. If your tractor has very few hours on it, you should vary your rpm's...according to the owner's manual anyhow. Some people do it that way, some don't.