Tire Pressure questions
Thread Starter
Instructor
Joined: Feb 2015
Posts: 155
Likes: 49
From: Kentucky
Tire Pressure questions
I've got a 2013 GS,running 10" P285/30ZR19 fronts and 12.5" 335/25ZR20 rears.Car tracks great on ridged roads at 39-40 PSI but DIC shows high pressure.At 35PSI no DIC ,but car wants to track worse.Any way to change the thresholds on the air monitoring system?Couldn't see anything in the owners manual.Thanks.Oh,Tires are Michelin OEM runflats off of a 2018.
Le Mans Master
Joined: Jan 2008
Posts: 6,457
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From: corpus christi Texas
I've got a 2013 GS,running 10" P285/30ZR19 fronts and 12.5" 335/25ZR20 rears.Car tracks great on ridged roads at 39-40 PSI but DIC shows high pressure.At 35PSI no DIC ,but car wants to track worse.Any way to change the thresholds on the air monitoring system?Couldn't see anything in the owners manual.Thanks.Oh,Tires are Michelin OEM runflats off of a 2018.
Thread Starter
Instructor
Joined: Feb 2015
Posts: 155
Likes: 49
From: Kentucky
Thanks,I'll drop another pound.
I guess your saying the tires because of the runflats?Had car realigned with the PFADT street specs but still had the OEM tires on it.Bought different wheels and the runflats were included.The runflats definitely track better than the OEM Goodyears.
I guess your saying the tires because of the runflats?Had car realigned with the PFADT street specs but still had the OEM tires on it.Bought different wheels and the runflats were included.The runflats definitely track better than the OEM Goodyears.
Last edited by KBu; Jun 11, 2018 at 09:46 PM.
Race Director
Joined: Jul 2005
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From: Central MO
Your door sticker calls for 30 psi, and I have found that to be a pretty good spot for the Vette. The Pfadt street alignment is a good neutral alignment that works well and contributes to longer tire life, at the expense of a little "at the limit" handling.
Le Mans Master
Joined: Oct 2000
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From: Sausalito CA
I too think you should lower the pressure.
OEM for Goodyear is 30PSI.
Not sure of the operating range (pressure or temps) for Michelin.
Yep, can not adjust the DIC warning it seems.
Tracking comment.
With your high pressures seems you are riding more on the center of the tire.
This could give quicker steering and lesson front road feel as the entire tread is not in contact with the road.
In the rear, I would guess traction as been reduced, straight line, yet when corning a little bit harder for me anyway to offer a comment.
One old rule of thumb is tire pressure should increase 10% from cold to hot.
So, if you run 35 cold, with hot tires should be 39 psi.
FWIW with 2005 Z51 Vert Firestone RFT for my road feel and wear patterns I run 33 ft 27 re.
Good luck.
OEM for Goodyear is 30PSI.
Not sure of the operating range (pressure or temps) for Michelin.
Yep, can not adjust the DIC warning it seems.
Tracking comment.
With your high pressures seems you are riding more on the center of the tire.
This could give quicker steering and lesson front road feel as the entire tread is not in contact with the road.
In the rear, I would guess traction as been reduced, straight line, yet when corning a little bit harder for me anyway to offer a comment.
One old rule of thumb is tire pressure should increase 10% from cold to hot.
So, if you run 35 cold, with hot tires should be 39 psi.
FWIW with 2005 Z51 Vert Firestone RFT for my road feel and wear patterns I run 33 ft 27 re.
Good luck.
Thread Starter
Instructor
Joined: Feb 2015
Posts: 155
Likes: 49
From: Kentucky
Thanks folks,I'll drop the psi and see how it feels.Shop that did the Pfadt alignment suggested the 40 psi .That was with the Goodyear F1 Supercar OEM's though.Thanks again for the input.
