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

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

 

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.

 

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!

 

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)

 

37 psi front
35 psi rear

 

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.

 

agree

 

1 psi makes no difference other than semantics

 

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

 

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

 

"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.

 

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.

 

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).

 

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.

 

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.

 

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.

 

^ 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.