If you run 30lbs, they will wear the shoulders. And how often do you want to check the inflation? We see a lot of tires. Most are worn excessively on the shoulders. A few are worn evenly. But I can't remember the last time I saw tires worn in the middle. The lesson here is to keep at least a little more than the door sticker recommends. How much is your call. But with cold weather here, and with most of us not being religious about monitoring our tire pressure, it makes even more sense to keep a little extra pressure in them.

On a rear wheel drive like yours, my rule of thumb is 5lbs over the door sticker. For front wheel drives, I still use at least 5lbs extra in the fronts, but only keep a couple of extra lbs in the rear, if there are not typically loads in the rear.

Just my