My suggestion is to go by the tires that are installed on the car, a inflated pressure will give you a stiffer ride but may increase your fuel milage. Lowering the pressure will give you a softer ride but less steering response and lower fuel mileage. Keep it within the recommended pressure on the side of the tire and watch the tread ware. I keep mine about 1-2 LBS below what the max pressure listed on the tire side, for fuel milage. Can’t help you with the chains, sorry