Gen 3 vs Gen 4 tire PSI recommendations; ZVW51L-AHXBBA model??

This is more of what one might call an academic question: why do Gen. 3 (in this case taking from 2010 manual) vs. Gen 4 (2017 manual here but I know 2022 is same) have different PSI specifications for otherwise very similar tires (slight difference in speed rating), with 35/33 for Gen 3 and 36/35 for Gen 4? Also why the variation in how much discrepancy between back and front, 2 vs 1 PSI? I did notice a difference in wheel size.

Also what is this "ZVW51L-AHXBBA model" thing? I could not follow the instructions in the 2017/2022 manual for how to figure out one's model and ascertain if your car was this model.

2010 Manual: 2010 Toyota Prius Manuals & Warranties | Toyota Owners

2017 Manual: 2017 Toyota Prius Manuals & Warranties | Toyota Owners

 

I figured out the "ZVW51L-AHXBBA model" is on the plate in the door with the VIN on it. Mine in 2022 Prius AWD-e LE is apparently ZVW55L-AHXEBA.

44psi is the max # on the sidewall of my OEM Bridgestone Ecopia EP422 Plus tires.

The dealership actually delivered it at that PSI and I didn't notice until after a 1000 mile road trip we took a week after getting it. After having car few weeks checked the tires because was feeling like rough roads really felt very rough and was wondering if that could be why. STreets/raods are in really bad condition in Brooklyn, NY where I live, and I think were much better on road trip I took early on.

I don't have really high standards for a smooth ride, the main cars I have ever driven a lot were a 2000 Honda Civic, a 1991 Plymouth Colt hatchback, and an old school VW van.

It seemed like lowering psi a bit closer to door placard recommendations (honestly can't remember what I have had it set at most of the time) helped have less rough ride but I also didn't drive it that much during school year when my teacher wife took it to work. Starting in April though I felt like I noticed the ride seeming rougher again and getting worse over time: I am probably going to get tires balanced and allignment checked and maybe suspension looked at, but first may play with tire pressure.

As I mentioned in other post we had BOTH a slow flat on front right and a major blow out on back left and had to totally replace back left tire, noticed both within days though not sure how long had slow falt (after replacing tire checked PSIs and noticed slow flat).

It now just really increasingly seems like feel every bump no matter how small and there's sometimes weird side to side front bounce, all of which I notice much more at lower speeds.

It's hard to believe increasing psi will help rather than harming but I will try it again. I actually did try few weeks ago and developed problem that dealership diagnosed as loose alloy wheel lock on the back right wheel where dealership had replaced tire. So I guess they didn't tighten that right. But still having issues with rough ride, side-to-side bounce esp. at low speeds on rough surfaces.

I might ultimately replace tires, do people have recommendations?

 

This is what you personally do? Why not the 36, 35 recommended in manual and door? Or do you have slightly different model with different recommendations?