I created a "tire pressure calculator" months back. it basically gives you the best PSI to maximize tire's load according to weight on each wheel. The recommended numbers are a minimum. i have been experiemnting with this along others on the internet and we found the recommendations to be generally acceptable. The only limitation is tires with thinner sidewalls. Since there is no definition for that yet, people with after market wheels may find the recommendation absurdly low but others with oem will find them close to manufacturer's recommendation. in no way is the recommendations by this software is to be taken seriously. So use it as your own risk. i on the other hand have had good experience with it.

for my TL-P stock recommendations were 34psi front, 32psi rear. this makes sense due to its heavier front. This also means that at a lower PSI the tire is strained & is carrying more weight than it can (in case of primacy mxv4 205-60r16). Full load (5 passengers) recommendations become 34-34. The recommendations for my previous BMW e46 are almost exactly the same as the manual.

link for software:
http://www.mediafire.com/?37cercne1siqnsm

let me know how this works for ya. its just an experiment for now.

 

how does it compare to percentage of car weight vs allowed max per tire
subtract weight percentage from max pressure
example 50 psi max, 80% car weight -subtract 20 % psi or 10 in this case for 40 running psi

adjust up or down 1-2 psi as needed for comfort, and `even across the tread` tire temps for those really into testing

 

^ im not sure about that. this one uses a more complex formula:

There is of course more calculations involved, like min tire pressure, weight ratio and etc. i have tried these formulas with lots of different car users on the internet and they find them to be ok.

 

I will stick with basic math for the ziners at large

 

what? cause all i read was basic.

 

Agree. Anyone trying to use a calculator to know where to set it at isnt really good. EVERY car and driver is different. Locations, road conditions, tires, ect ALL play into effect. I change mine every time i get a different brand of tires. Every set is different. The 80% rule and adjust from there works best.

Even stuff like lapping days and auto-x Ill start the PSI about 10+ less than normal street use as the tires will gain close to that on warm days.

 

Game to this topic, whenn searching for "tire-pressure-calculator" , and saw that you use the formula that I trew on the internet , wich is the official one used by the European Tyre-makers , and since 2006 also the American tire-makers. I wont introduce me in a seperate topic because I dont drive an Acura.
So I registered to give you some background information about it.

I got hold of this formula and its extra's in 2007 , and worked it out.
Learned myself Excell to make spreadsheets for it, and translated a few to English to go worldwide with it.
Reacted on many fora, also Americans , and found out that this formula is not that holy as I declared it.
Found an article of J.C. Daws with an other formula and comparison with this old power formula ( ^1,25 or ^0,8) , and its different powers used in America and Europe.
The Power formula is introduced in 1928 for diagonal tires with power ( to calculate load for a sertain pressure) of 0,585, and later adjusted for radial tires in Europe to 0.8 and in America to different powers for diferent tire-types. 0.5 for normal car tires with aspect ratio of more then 50%.
0.65 for those with Asp Rat of less then 50% .
From C load ( not important here) 0.7 .
In 2006 American TRA swiched to the European ETRTO power , saying it was for global going to the same system, but only for normal ( P or SL) and XL ( reinforced/Extra load) , From C load still 0.7 is used.
My conclusion of the Ford/Firestone-affaire, and the article of Daws , is though ( search for it and draw your own conclusions) that TRA calculated wrong before 2006 , wich led to to low pressures and so tire-damage.

I wil stop for the moment with giving you link to my public map of skydrive/hotmail, where you can navigate trough, like in a forum.
In the map all about tire-pressure" my own idea of how a tire bends and my own formula , wich is a mix of the "Daws linear constructionload formula"and the old power formula.
https://skydrive.live.com/?cid=a526e...E092E6DC%21128
To open spreadsheets , click on the I in a cirlce at the end of the line, then in the right barr at download, and open it in Excell or compatible program to use it. If you press wrong, the browser will try to open it, but cant handle some things I used in the spreadsheets. Also dont press "open in Excell", for that you have to sighn in with your Email adress, to much work.
If you want to mail me, my hotmail adres has the same username as here, so combine it yourself. spamm-robots cant like this.

 

^ hey thanks for this. I will investigate soon.

 

I found this information on Toyos site for my 05 with 245/35/19 Proxes4 So I should have 39psi apparently.

http://tirefinder.toyotires.com/?vid=24262