Measured my tire wear (20,000+ miles at elevated pressure - 44 PSI)

[MaxHedrm]

Originally Posted by F8L

If you are going to make blanket statements such as the FUD above you should provide us with details and data that proves your point.

While his justifications are not entirely accurate, he has valid points. Of course you'll likely blow everything I'm about to say off as anecdotal, & if so, that's fine. Just try not to hit me when you lose control of your car...

Having tracked a couple different vehicles, I can speak to how inflation pressure effect handling limits. A common way to induce a bit more neutral handling in cars that are tuned from the factory to understeer is to over inflate the rear tires. This reduces the traction in the rear, making it rotate through turns a bit easier. This is exaggerated (and unpredictably so) on rough surfaces since a really full tire will bounce over those imperfections. (Think of bouncing a volley ball when it is full vs under inflated.)

So, unless you drive on billiard table smooth roads there in Sacramento, be careful with those hyper inflated tires.

I'm certainly not saying to inflate them to 32psi or something, but definitely keep the effects in mind.

[WE0H]

Originally Posted by Russjd

Blanket Statement?
FUD?

Because you Never had a tire failure,
Because you Never had an accident,
what instrumentation are you using to determine "your car's handle way better"?

I go buy.... max tire contact = max braking, cornering (at "normal" speeds)

I'm an old school autocrosser so I tend to feel what changes are doing something good or bad. Any of my non-official testing is done at any speeds my vehicles are capable of or the road conditions are capable of. I haven't been on a track in many years and don't know if my current ride would be so great as the Plus wheels/tires slow down the acceleration too much to make it a competitive vehicle. Maybe some day when someone figures out how to read & write to the Prius computers and I can crank up the electric torque in the software

I didn't come on here to attack anyone, so don't take any comments I make serious.

Mike

[F8L]

Originally Posted by Russjd

Blanket Statement?
FUD?

Because you Never had a tire failure,
Because you Never had an accident,
what instrumentation are you using to determine "your car's handle way better"?

I go buy.... max tire contact = max braking, cornering (at "normal" speeds)

And how are you determining max tire contact? What pressures and what tires and what load? Yes FUD. Fear Uncertainty or Death. :roll-eyes: The truth is, when pressure is kept at or below the sidewall max pressure, contact patch integrity is retained and very little if any contact patch is reduced. Stopping distance is not drastically altered by more than a few feet +- depending on whether you're driving on concrete or asphalt.

Max, I would not argue your points because i agree with them but you never stopped to ask me what I consider overinflated and wrongly assumed I run "hyperinflated" tires, whatever that means. Generally speaking most of the road surfaces I drive on at speeds over 45mph are quite smooth so inflating to even 50psi (51psi max) doesn't induce a lot of bouncing or skipping but for safety and comfort reasons I don't go that high except for testing purposes. A tire inflated near sidewall max (hot) has the benefit of a stiffer sidewall which helps quicken steering response and keeps the tire from rolling over onto the sidewall in hard cornering. It also decreases deformation/deflection which reduces heat buildup thus resisting heat induced blowouts and excess tire wear. I'm sure you've experienced this if you have ever ran autocross events. This also helps to keep the car under control in the event you have to perform an evasive maneuver. The Prius comes with fairly undersized tires, especially on the GenII, so adding pressure above placard levels (33/35psi) creates more stable handling, slightly better fuel economy, and even tire wear. Even so, no one on our forum ever recommends running above sidewall max pressure and they often recommend less if the end user drives on poorly maintained roads. IMO that is not hyperinflation nor do tire manufactures consider it so from what I have read and I do read a lot. It's amazing what you can learn from racing tech and the trucking industry! LOL

[WE0H]

Originally Posted by F8L

And how are you determining max tire contact? What pressures and what tires and what load? Yes FUD. Fear Uncertainty or Death. :roll-eyes: The truth is, when pressure is kept at or below the sidewall max pressure, contact patch integrity is retained and very little if any contact patch is reduced. Stopping distance is not drastically altered by more than a few feet +- depending on whether you're driving on concrete or asphalt.

Max, I would not argue your points because i agree with them but you never stopped to ask me what I consider overinflated and wrongly assumed I run "hyperinflated" tires, whatever that means. Generally speaking most of the road surfaces I drive on at speeds over 45mph are quite smooth so inflating to even 50psi (51psi max) doesn't induce a lot of bouncing or skipping but for safety and comfort reasons I don't go that high except for testing purposes. A tire inflated near sidewall max (hot) has the benefit of a stiffer sidewall which helps quicken steering response and keeps the tire from rolling over onto the sidewall in hard cornering. It also decreases deformation/deflection which reduces heat buildup thus resisting heat induced blowouts and excess tire wear. I'm sure you've experienced this if you have ever ran autocross events. This also helps to keep the car under control in the event you have to perform an evasive maneuver. The Prius comes with fairly undersized tires, especially on the GenII, so adding pressure above placard levels (33/35psi) creates more stable handling, slightly better fuel economy, and even tire wear. Even so, no one on our forum ever recommends running above sidewall max pressure and they often recommend less if the end user drives on poorly maintained roads. IMO that is not hyperinflation nor do tire manufactures consider it so from what I have read and I do read a lot. It's amazing what you can learn from racing tech and the trucking industry! LOL

IDK, you drive a Prius, you just can't know anything about car handling

Mike

[Nevyn]

Originally Posted by Russjd

Blanket Statement?
FUD?

Because you Never had a tire failure,
Because you Never had an accident,
what instrumentation are you using to determine "your car's handle way better"?

I go buy.... max tire contact = max braking, cornering (at "normal" speeds)

By those rules, you'd have max contact with a flat tire. Do you run all your tires at 0 PSI?

Oh. Didn't think so.

[WE0H]

Originally Posted by Nevyn

By those rules, you'd have max contact with a flat tire. Do you run all your tires at 0 PSI?

Oh. Didn't think so.

That was funny

Mike

[evilskillit]

In the following NHTSA tests higher inflation resulted in shorter braking distances, tho hyperinflation was not tested. Also worth noting the distances in most cases were only a few feet.
TIRE PRESSURE SURVEY AND TEST RESULTS

I think another forum member did some testing and found no appreciable stopping distance difference all the way up to 50psi, but I can't find it. If you've got something that says that pressures above 30psi make braking measurably worse I'd like to see it. Like really not sarcastically I'd like to see that so I know.

[CapriRacer]

Originally Posted by strangewierding

The benefits of increasing the pressure in your tires......

I truncated this post just so everyone knows what I am responding to - but I don't want to repeat bad information - thereby reinforcing it.

Also: Strange Wierding - I hope you don't think I am picking on you. My intent is to get good information in your head and let you take it from there.

First, Tire Construction: Most passenger car tires are made of 1 or 2 polyester body plies. They go radially (straight across - 90° to the circumference) from bead to bead - and even wrap around both beads, so that in the lower sidewall area, there are even more layers.

Passenger car tires usually have steel belts and always in pairs. Belts are in the tread area only and each layer is at about a 15° angle (relative to the circumference), but in opposiyte directions. What this means is that as more pressure is added to the tire, the belts change angle (becoming more circumferential) and the tire not only grows in diameter, but the center of the tread expands more than the shoulder. Increasing pressure has a decreasing effect, but it is still there. The process is called "pantographing".

Some passenger car tires have nylon cap plies (1 or 2). These are circumferential, under the tread area only, and resist growth in the tread area. You'll definitely find nylon cap plies in H and higher speed rated tires.

[euromodder]

Originally Posted by mad_b

I thought 44psi would be the pressure limit for a regular radial tire to be inflated.

Mine are rated at 51 psi / 3.5 bar
(49 / 3.4 for the winter rubbers)

[euromodder]

Welcome to ecomodder.

Originally Posted by KGM

I drive on European roads (more corners) on 195/65R15 tires with 2.8bar = 40PSI
/manufacturer's recommendation - 2.3bar/

Dunno what car you have, but if that's on a Volvo, it's way too low