DURSO

What is the correct (cold) tire pressure for 19" SO3 tires?

245/35/19 front on 19x8.5
275/35/19 rear on 19x9.5

I was told 40psi. Does this sound right?

The tire has a max psi of 51.

Thanks for the help!
Tony

johnlotusboy

iTrader: (1)

Please verify the load range number for me on the sidewalls of the front and rear, but from the info I can find it says rear same as original tires and front 1-2psi less than oem tires. this is bases on the load range numbers on the tire, this info says how much weight a tire will support at what inflation base on its load range. This should be within a pound or two. I will post a chart from a local tire store later this evening.

DURSO

I ended up getting a set of 19" Michelin Pilot Sport A/S in:
245/35/19 front on 19x8.5
275/35/19 rear on 19x9.5
Max PSI is 51.

Load is:

1279 lbs front
1565 lbs rear.

Thanks - Tony

shaneotool

How about 19" Toyo's?

What PSI are you guys using on those?

johnlotusboy

iTrader: (1)

The sidewall on the tire will have a number on it after the size and that number will have a speed rating letter after it, different brand and constuction (meaning pilot sport vs. pilot sport all-season or brand to brand) can/will have load range number.
What I am looking for is for that specific number on the tire you are running.

Example: 245/45-17R 94Y
The number I am refering to is the "94"

The pilot sport in your front size is a 93 if it is the Extra load (XL) version, if it is the standard version it is a 89. The all-season pilot sport is an 89.
I need the number off the tire you have on your cars then I can look up and advise you on a starting point for the inflation. You may find that a pound or two adjustment from there is optimum for you particular set up but it will get you close enough to have even tire wear, good traction, decent handling and a bearable ride on the street..

DURSO

O.K..... I have the Michelin Pilot Sport A/S

245/35/19 Front - 89Y M+S
275/35/19 Rear - 96Y M+S

Thanks for the help!

johnlotusboy

iTrader: (1)

Your rears are the same as the original for loadrange so 35 psiis correct for them. Your fronts are another story, the chart I have and what you said is the new tires have a maximum load of 1279 pounds the original tires support 1433 pounds at 35 psi. Your new tires are not designed to hold up the weight loads for the 350Z. I don't know where you will run them but it will be a high pressure but don't exceed max. inflation stated on sidewall of tire.

DURSO

Thanks for the info.

I will run the rears at 35psi.

Do you think that 40-44 psi in the fronts will be o.k.? Max PSI is 51.

What would you suggest for the fronts?

johnlotusboy

iTrader: (1)

Minimum on the front is 36 you don't really gain that much more load capacity going all the way to max. inflation of 51psi. You will need to look and see if the tire is rolling over the sidewall at lower pressures. I would start at 40 and look at the wear/ dust pattern after a couple of real hard corners or donuts in a parking lot. Just get the front to start pushing while doing your basic skid pad manuver then look at the tires. If you start out over inflated it won't show signs of contact at the outside edges and you can lower till you get to the edge of the tire and you will feel the difference. Overinflation will just wear out the center of the tire faster and give a harsh ride, and since that is all that is touching you will have a longer braking distance and a greater amount of understeer due to the reduced contact patch.
It's all a tunning thing working with tire pressures.

DURSO

Your the man!

Thanks for the help. I will keep you posted. I am going to start out at 40psi and go from there.

zh.guitar

iTrader: (1)

what about these:

Toyo Proxes t1-s

front 275/35 ZR19 96Y

rear 245/40 ZR19 98Y

I'm running at 34 cold. It's warm here and during the day they get up to about 37/38 psi. Tire wear seems even so far (600 miles).


thanks,

Sanderman

Same with me, my Toyo T1-Ss are 245-40-19 98Ys front and 275-35-19 96Ys rear. Load range stated on each is 1653 front and 1565 rear at max inflation pressure of 50 front and 44 rear.

The tire dealer set cold pressures at 43 PSI front and 37 rear but that rattled out my fillings. I'm running 37 front and rear now with a better overall feel.

Any better guidance you can offer?

joe

johnlotusboy

iTrader: (1)

ZH. Guitar and Sanderman,
The original tires on the rear are a loadrange 96 so back to stock +/- a little bit should fine , The fronts you are going to want to reduce to about 30, I would start at 32 and see how it feels.
These are cold inflation numbers. If the pressure creep when they heat up causes the ride to get rough try filling the tires with nitrogen to reduce the amount of temp. induced pressure rise.

I learned a lot about the inflation issues with my Lotus oem tires on the front run 21 or 23 psi depending on the brand and the rears ran 26. That was with 195/60/15 Front and 235/60/15 Rear, then I changed to 225/45/16 Front and 275/40/17 Rear.
It was quite a learning experience to get those dialed in.

Sanderman

Thanks! I'll try it this weekend.

Joe

DURSO

If the Z's total weight is 3197lbs, then 53% (Front weight distribution) would equal 1695lbs for the front 1/2 of the car. If you divide that by 2 (R and L tires), that # is only 848lbs of load.

Question is, why does the Z require such a high load rated tire? My fronts have a load rating of 89y which is 1279lbs. each.

Sorry if this is a dumb question....I am not to familiar with tires and loads.

Also, Is there a formula to follow for Load/Inflation when you are using a otherwise load rated tire???

Thanks for helping me understand.

DURSO

Can anyone add anymore on this?

So far I am at 41psi front, and the wear/dust pattern looks to be just right.
Rears at 35psi, and those are perfect.