1. Attachments are working again! Check out this thread for more details and to report any other bugs.

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

Discussion in 'Gen 4 Prius Main Forum' started by Dan Y, Jun 17, 2022.

  1. Dan Y

    Dan Y Junior Member

    Joined:
    Aug 21, 2021
    50
    8
    0
    Location:
    Brooklyn, NY
    Vehicle:
    2022 Prius
    Model:
    LE AWD-e
    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
     

    Attached Files:

  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    psi recommendations are based on vehicle structure and weight. gen 4 is independent rear suspension, first in a prius.

    i thikthe zvw thing refers to the engine, but all prius have the same engine within generations
     
    Pulse07 and Dan Y like this.
  3. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Tyre Pressure will also have a bearing on vehicle driving behaviour. To balance oversteer, they might increase REAR pressures.

    Any of us who remember old Rear Engine VWs and Renaults - will well know how the way they drive depends on both the quality and pressures FR/RR of the tyres.

    Gen 4 has a totally different chassis and body - nothing is carried over from Gen 3.
     
    Pulse07 and Dan Y like this.
  4. Billy56

    Billy56 Member

    Joined:
    Oct 16, 2019
    64
    58
    0
    Location:
    Seattle, WA
    Vehicle:
    2020 Prius
    Model:
    L Eco
    Both cars.....just inflate to 50 lbs pressure and call it good. It says 44 lbs max on the tire sidewall....I ALWAYS run 50 lbs.....better fuel economy!
     
    Geoff Hejde and Dan Y like this.
  5. 2010moneypit?

    2010moneypit? Active Member

    Joined:
    Oct 26, 2021
    314
    122
    0
    Location:
    Beaumont ca
    Vehicle:
    2010 Prius
    Model:
    V
    I always run max on the sidewall of the tire. I am too chicken to go above tire manufacture max pressure. When you drive the tires heat up and the tire pressure increases especially when we have warmer ambient temperatures This is the reason I fill my tires the indicated max pressure on the sidewall of the tire. Most if not all manufactures recommend that you fill the tires when cold. (Before the car has been driven)
     
    alanclarkeau and Dan Y like this.
  6. Dan Y

    Dan Y Junior Member

    Joined:
    Aug 21, 2021
    50
    8
    0
    Location:
    Brooklyn, NY
    Vehicle:
    2022 Prius
    Model:
    LE AWD-e
    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?
     
  7. PaulDM

    PaulDM Active Member

    Joined:
    Sep 24, 2016
    616
    317
    2
    Location:
    UK
    Vehicle:
    2022 Prius
    Model:
    Excel
    37 psi front
    35 psi rear
     
    Dan Y likes this.
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    increasing pressure will not help smooth the ride, it will help mpg's marginally.

    lowering pressure smooths the ride, but don't go under the spec. and remember to check them based on ambient temp.
     
    alanclarkeau, Dan Y and 2010moneypit? like this.
  9. 2010moneypit?

    2010moneypit? Active Member

    Joined:
    Oct 26, 2021
    314
    122
    0
    Location:
    Beaumont ca
    Vehicle:
    2010 Prius
    Model:
    V
    agree
     
    Dan Y likes this.
  10. Dan Y

    Dan Y Junior Member

    Joined:
    Aug 21, 2021
    50
    8
    0
    Location:
    Brooklyn, NY
    Vehicle:
    2022 Prius
    Model:
    LE AWD-e
    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?
     
  11. PaulDM

    PaulDM Active Member

    Joined:
    Sep 24, 2016
    616
    317
    2
    Location:
    UK
    Vehicle:
    2022 Prius
    Model:
    Excel
    1 psi makes no difference other than semantics
     
    Pulse07, Dan Y and Mendel Leisk like this.
  12. jteran5

    jteran5 Active Member

    Joined:
    Nov 4, 2019
    408
    202
    0
    Location:
    NJ
    Vehicle:
    2019 Prius
    Model:
    XLE AWD-e
    ZVW50 = Regular Prius
    ZVW51 = I believe is for the higher trims like the Four or Touring (2016-2018) or Limited (2019+) designating higher weights and options
    ZVW52 = Plug-In/Prime
    ZVW55 = AWD / E-Four

    Posted via the PriusChat mobile app.

    I always get confused with the ZVW51
     
    #12 jteran5, Jun 18, 2022
    Last edited: Jun 18, 2022
    FuelMiser and Dan Y like this.
  13. NewHybridOwner

    NewHybridOwner Active Member

    Joined:
    Nov 21, 2018
    607
    278
    0
    Location:
    W. Michigan
    Vehicle:
    2015 Prius
    Model:
    Four
    There are so many threads at PriusChat about tire pressures that I certainly haven't read all of them, but I don't recall seeing anyone pointing out that the higher the pressure, the smaller the area of the tread in contact with the road: only a narrow band in the middle, which I think would be disadvantageous for handling, especially on wet surfaces. Conversely, underinflated tires tend to have two narrow bands of contact, one at each edge, leaving little of the center of the tread in contact with the road surface.
    These pictures are an exaggeration, of course, but you get the idea:

    https://cdn.discounttire.com/sys-master/images/hd9/h56/8812799164446/EDUtire-pressure_over-underinflation.png
     
  14. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,041
    7,580
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    "the higher the pressure, the smaller the area of the tread in contact with the road"
    That was relevant to cross-ply tyres - RADIALs work quite differently.
     
    BiomedO1 likes this.
  15. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,036
    10,010
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    This has been both claimed, and disputed for most modern steel radial tires, in very many threads here. It seems that the number of drivers who get more even tire wear at increased pressure, has exceeded those who experience excessive center wear.

    For old-era bias ply tires, there seems to be no dispute about the connection between overinflation and excess center wear.
    There are at least two separate wet traction issues: wet traction without hydroplaning; and hydroplaning itself.

    All the technical information I've seen on hydroplaning shows that higher tire pressure pushes up the speed at which hydroplaning starts. Between living in an often wet climate zone, and having experienced premature hydroplaning on a couple previous cars when tires were set to the car manufacturer recommendation, I've since been a proponent of at least somewhat boosted tire pressure. It turns out that both my independent mechanics (for different car brands) feel the same.

    As for non-hydroplaning wet traction, that issue seems to be ... disputed and unsettled.
     
    alanclarkeau likes this.
  16. Doug McC

    Doug McC Active Member

    Joined:
    Feb 15, 2022
    940
    343
    0
    Location:
    Midwest
    Vehicle:
    2022 Prius
    Model:
    XLE
    FWIW: 2022 Nightshade, 17” tires the recommended pressure is 33/32.
    Pressure recommendations are based on a lot of things including suspension components, even the wheels (which actually have tire pressure limits too).
     
  17. NewHybridOwner

    NewHybridOwner Active Member

    Joined:
    Nov 21, 2018
    607
    278
    0
    Location:
    W. Michigan
    Vehicle:
    2015 Prius
    Model:
    Four
    I looked at a few different tire manufacturers' and tire stores' Web sites, and they all say the same thing as I wrote originally -- and with similar pictures, and with no suggestion that it is not still a problem with radial-ply tires.
     
  18. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,036
    10,010
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Recommended tire pressures are a tradeoff between competing goals, and it seems that car makers very heavily weight the ride comfort goal. Empirical evidence from the hypermiling communities suggests that numerous of those door placard labels are biased in the direction of underinflation, at least for tread wear. The number of experimenters getting better treadwear with increased pressure, in the form of reduced edge wear, seemed to greatly exceed those who experienced center wear. This suggests that the breakpoint between 'correct' inflation and 'over' inflation, is higher than most of those drivers use, and well above what most of those car maker put on their recommendation labels.
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,473
    38,105
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    They roll out of the factory at max sidewall, mainly for shipping concerns, and possible protracted parking. Dealership was supposed to drop the pressures, but basically dropped the ball. Mention to service manager and you might get a free oil change or sim. You pay a pretty penny for PDI, and they rip you off.
     
  20. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,036
    10,010
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    ^ A good many of us received our Gen3s with at or very close to 40 psi in the tires, and not lowered at PDI. Then a good numbers of Gen4 buyers reported getting theirs with about 50 psi.

    I believe some tire models for these cars have sidewall label max ratings of 51 psi, but most are marked for 44 psi.