Just purchased a set of 15" Michelin snow tires for 2013 Prius 4. Wondering what best pressure is for mpg. Max pressure on sidewall says 50 psi. Thanks.
Short answer is 50 psi. When in actual snow or mud, you may need to reduce a bit toward the door placard values. Technical answer to your question is just below burst pressure, but you don't want that. If NVH is too great for your taste or conditions, lower a bit from 50 psi. Make rear tires 2 psi less than fronts.