Tire pressure

Just look at the rated tire pressure on the side of the tire. As TM says, the more air pressure, the easier the vehicle will roll, but will ride harder.

Never fill your tires to what the max psi says on the sidewalk of a tire. That’s the max pressure the tire can withstand. Each vehicle weighs different and there’s a sticker inside your driver or passenger door frame that gives you the vehicle specific tire psi. Tire psi is vehicle specific based upon weight and how the vehicle squats the tire down against the road. It is not tire specific. Tires only show the max psi they can hold. Filling to the tire specific max psi will cause tire blow outs and extremely uneven wear on your tire. It doesn’t give you any benefits. So whoever said that is wrong. I work specifically as a tire tech so I know this as fact.