Squared 20 Inch Set Up - Same PSI in tires?

[StingerSeth]

Might be a silly question, but I've never gone from staggered to squared before. I'm running 255/35ZR20/XL 97Y Michelin Pilot Sport A/S 3+ on all 4 corners. Do I keep the same tire pressure settings as the stock 19's (38 psi Front/36 psi Rear)? Thanks in advance!

 

[Capecod]

I would think so, I just changed my stagers 19” to winter square 18” and the paper work said to go by what was manufacturers recommendations on door sticker

 

[Silverghost]

A member on this forum, Ty Davis, posted a very helpful chart which I am re-posting here, in a thread called: tire-pressures-for-non-standard-sized-tire-rim-combos
Sorry, I cannot figure out to post a link to that thread.
All thanks should go to Ty Davis.

 

[StingerSeth]

A member on this forum, Ty Davis, posted a very helpful chart which I am re-posting here, in a thread called: tire-pressures-for-non-standard-sized-tire-rim-combos
Sorry, I cannot figure out to post a link to that thread.
All thanks should go to Ty Davis.

Thanks! And thank you Ty if you’re reading. Based on that chart and my tire info it looks like I want 33 psi front and 35 rear? Our stock GT Michelin 19s’ load index are 93 front 96 rear correct?

 

[Silverghost]

Sounds about right...

 

[Capecod]

Thanks! And thank you Ty if you’re reading. Based on that chart and my tire info it looks like I want 33 psi front and 35 rear? Our stock GT Michelin 19s’ load index are 93 front 96 rear correct?

Based on that chart is it saying the original 19" Front 93Y 1433 lbs and 19" Rear 96Y 1565 lbs should be 42 PSI ?

My new winter tires are 95V 1521 lbs and should be 39 PSI ?

 

[StingerSeth]

Based on that chart is it saying the original 19" Front 93Y 1433 lbs and 19" Rear 96Y 1565 lbs should be 42 PSI ?

My new winter tires are 95V 1521 lbs and should be 39 PSI ?

I believe our OEM 19s are XL reinforced so we should be using that chart. My aftermarket 20s are definitely XL reinforced. Have to double check on the 19s when I get home but I’m pretty sure that’s the case

 

[Capecod]

I believe our OEM 19s are XL reinforced so we should be using that chart. My aftermarket 20s are definitely XL reinforced. Have to double check on the 19s when I get home but I’m pretty sure that’s the case

They are

Front: 225/40ZR19 (93Y) XL

Load Range: XL Max load 1433lbs

Serv. Desc: (93Y) Load index 1433lbs Y rating 186+

UTQG: 320 AA A


Rear: 255/35ZR19 (96Y) XL

Load Range: XL Max load 1565lbs

Serv. Desc: (96Y) Load index 1565lbs Y rating 186+

 

[StingerSeth]

They are

Front: 225/40ZR19 (93Y) XL

Load Range: XL Max load 1433lbs

Serv. Desc: (93Y) Load index 1433lbs Y rating 186+

UTQG: 320 AA A


Rear: 255/35ZR19 (96Y) XL

Load Range: XL Max load 1565lbs

Serv. Desc: (96Y) Load index 1565lbs Y rating 186+

Welp...I’m beyond confused now

 

[Capecod]

Welp...I’m beyond confused now

Me too ha ha

 

[StingerSeth]

Me too ha ha

Maybe those specs are just stating the max psi that the OEM tires can be filled to (42psi)? Hopefully someone can chime in and help us figure it out lol

 

[Silverghost]

The way I have read this chart is as follows:
Existing fronts- look for line corresponding to 93 and column 38 psi.
That intersect of 1322 is what you are trying to find the corresponding psi for on the 97 line (your new tire).
The closest to that on the 97 line is 1319 which is in the 33 psi column.
That is the pressure calculated for new front tire assuming the same load from Kia...
You were right (in my view) with 33 front and 35 rear.
I hope this helps.
I am no specialist...

 

[Capecod]

The way I have read this chart is as follows:
Existing fronts- look for line corresponding to 93 and column 38 psi.
That intersect of 1322 is what you are trying to find the corresponding psi for on the 97 line (your new tire).
The closest to that on the 97 line is 1319 which is in the 33 psi column.
That is the pressure calculated for new front tire assuming the same load from Kia...
You were right (in my view) with 33 front and 35 rear.
I hope this helps.
I am mo specialist...

Thanks, I was reading it using the 19" tire load rating from Michelin not KIA's PSI recommendation of 36 R and 38 F.


so in my case with the new tire 95V the rears should be 34 and fronts 40

 

[moinmoin]

Do I keep the same tire pressure settings as the stock 19's (38 psi Front/36 psi Rear)?

Yes, because not much has changed from the original setup, mostly the diameter of the overall wheel, which changed from 26" to 27".
But the margin protecting the rims from contacting the road surface when you encounter potholes remains the same: 3.5" all around.
If you reduce from the recommended tire pressure, you may notice a certain lack of crispiness has gone from the steering response and the car will not feel as planted.

I live in a colder climate and increased the tire pressure now to 40 psi during the colder months. When it's freezing outside, TPMS indicates something like 36 psi or lower, and only after going a fair distance, pressure creeps up to 38 psi and maybe 40.
This is going to be my 3rd winter on these tires and I feel my rims & rubber are adequately protected.

For advice & confirmation purposes, you may want to talk to the people that sold you the tires. Good luck.

You probably realize that the car's speedometer and tachometer are calibrated for 26" wheels and without correction will read lower than actual speeds and lower than actual distances traveled.

 

[Tonkabob]

Stay with stock pressure. Rear is identical to stock (but taller rim) and the front carries more weight.

 

[Capecod]

I sent an email to tire rack yesterday and they said go with what the manufacturer recommends.