I have an extended warranty on my 2012 Toyota Highlander with a 3.5L V6. The warranty runs until 100K miles. I'm using 0W20 and have used that weight since I got it. I have a few more OCIs before my warranty runs out and have enough 0W20 stashed to get well past 100K miles on my existing supply of oil. I'm just wondering about down the road if it would be suitable to run it on 5W30 synthetic like I use for my other vehicles. I'm assuming it would since this engine USED to be spec'd for 5W30. Essentially, I'm just curious if anyone has switched from 0W20 to 5W30 on this specific engine and if they are happy with their decision. I don't have a problem using 0W20, but using the same weight across the board would be nice. I'm also wondering if using a thicker oil as the engine ages would be beneficial.
Thanks!