high mileage oil weight?

I have a 2011 silverado 5.3L which I got around 80k miles. Ive been running Pennzoil Ultra Platinum 5w-30 Synthetic since I got it. I was looking into running a high mileage synthetic like mobile 1 high mileage full synthetic but wasn't sure If I should stick to the factory recommended 5w-30 or Ive read that some people change the oil weight in high mileage vehicles. What do you think? I have about 97k miles on it now.

Thanks in advance for your suggestions.