IS F (2008-2014) Discussion topics related to the IS F model

tire pressure questions

Thread Tools
 
Search this Thread
 
Old 09-21-12, 01:59 PM
  #1  
2ndGF
Lexus Test Driver
Thread Starter
iTrader: (1)
 
2ndGF's Avatar
 
Join Date: May 2012
Location: SoCal OC/LA
Posts: 1,227
Likes: 0
Received 4 Likes on 4 Posts
Default tire pressure questions

What tire pressures are you guys running on stock setup?

At what pressure does the TPMS light come on?

Can you set what pressure you want the light to come on at?
Old 09-21-12, 04:29 PM
  #2  
RCB
Lexus Test Driver
iTrader: (18)
 
RCB's Avatar
 
Join Date: Jan 2010
Location: MA
Posts: 964
Received 9 Likes on 8 Posts
Default

Originally Posted by 2ndGF
What tire pressures are you guys running on stock setup?

At what pressure does the TPMS light come on?

Can you set what pressure you want the light to come on at?

1. Refer to the label on the drivers door jamb

2. 29psi if I remember right (that's sort of a guess) , it's in the owners manual

3. No
Old 09-21-12, 04:44 PM
  #3  
digger08
Lexus Test Driver
iTrader: (1)
 
digger08's Avatar
 
Join Date: Jan 2004
Location: Canada
Posts: 1,028
Received 10 Likes on 8 Posts
Default

TPMS thresh holds can also be altered in the Techstream. .......the previous owner of my car had them set at 26 psi. Not sure what the maximum tolerance is for this?



Digger08
Old 09-22-12, 10:28 AM
  #4  
2ndGF
Lexus Test Driver
Thread Starter
iTrader: (1)
 
2ndGF's Avatar
 
Join Date: May 2012
Location: SoCal OC/LA
Posts: 1,227
Likes: 0
Received 4 Likes on 4 Posts
Default

I know that 36 is manufacturers suggested psi - i was wondering what you are all running instead - i usually do 35 psi
Old 09-22-12, 11:38 AM
  #5  
FD3SISF
Lead Lap
iTrader: (2)
 
FD3SISF's Avatar
 
Join Date: May 2012
Location: SoCal
Posts: 664
Likes: 0
Received 0 Likes on 0 Posts
Default

I'm running 40 on the front and 34 on the back. It was the recommended tire pressure for grip and tire life by the race alignment shop when I had my alignment done. I was just gonna do 36psi all around, but when I went to their shop and saw them working on a 69 mustang and a murcielago. I just stick to their recommendation. Haven't tested it yet in the canyons and track.
Old 09-22-12, 12:29 PM
  #6  
Just F Me
Lexus Champion
 
Just F Me's Avatar
 
Join Date: Sep 2008
Location: SoCali
Posts: 2,284
Likes: 0
Received 22 Likes on 9 Posts
Default

Not using recommended tire pressures can lead to uneven tire wear and/or accelerated tire wear and/or decrease in fuel economy (I know that last one is very important to many of us) it's on the door for a reason.

But if you want more grip, run it slightly lower...or better yet, just buy better tires.

Also, unless you have a very high grade tire pressure gauge, you won't know the difference between 36 and 35. I believe our TMPS light comes on at 30psi
Old 09-22-12, 04:31 PM
  #7  
ISF001
Lexus Champion
 
ISF001's Avatar
 
Join Date: Dec 2011
Location: PA
Posts: 2,083
Received 3 Likes on 3 Posts
Default

Originally Posted by 2ndGF
What tire pressures are you guys running on stock setup?

At what pressure does the TPMS light come on?

Can you set what pressure you want the light to come on at?
I am running 35 in the front and 37 in the rear...recommended by my shop. Who knows...
Old 09-22-12, 04:33 PM
  #8  
VicTornin
Driver
 
VicTornin's Avatar
 
Join Date: Mar 2012
Location: DR
Posts: 169
Received 0 Likes on 0 Posts
Default

I am running 32 all around... Feels fine for me
Old 09-22-12, 04:35 PM
  #9  
Supraman16
Advanced
iTrader: (5)
 
Supraman16's Avatar
 
Join Date: Apr 2001
Location: Burbank, CA
Posts: 586
Received 37 Likes on 19 Posts
Default

It varies for different types of tires. My NItto Invo's which had relatively soft sidewalls did best at 40psi. I'm currently on Michelin Pilot Super sports are the fee very floaty at the same 40psi. I have since brought them down to the Lexus recommended 36psi (as noted on the label on the driver side door) and feel great at these pressures...Darshana S...
Old 09-22-12, 05:32 PM
  #10  
psixtc
Pole Position
 
psixtc's Avatar
 
Join Date: Apr 2012
Location: TX
Posts: 278
Likes: 0
Received 0 Likes on 0 Posts
Default

The TPMS light should come on if the tire pressure falls below 78% of the set point.
Old 09-22-12, 09:27 PM
  #11  
VtotheJ
Lexus Champion
iTrader: (2)
 
VtotheJ's Avatar
 
Join Date: Apr 2011
Location: NY
Posts: 2,546
Received 5 Likes on 5 Posts
Default

My tpms light went on a few days ago and my pressure was ~28 psi. I just reinflated to 36 psi.
Old 09-22-12, 11:24 PM
  #12  
CalitriSC
Lexus Champion
iTrader: (13)
 
CalitriSC's Avatar
 
Join Date: Feb 2011
Location: Las Vegas
Posts: 4,020
Likes: 0
Received 7 Likes on 3 Posts
Default

I run 38psi all around, but thats on aftermarket wheels.
Old 08-10-14, 11:30 AM
  #13  
Gymkata
Instructor
 
Gymkata's Avatar
 
Join Date: Dec 2009
Location: MD
Posts: 1,102
Received 28 Likes on 20 Posts
Default

I figure it is easier adding to this thread than starting a new one.

I just finished a VDI (Vehicle Dynamics Institute) driving course...on road, off road, and vehicle combatives. They taught that vehicle manufacturers often recommend tire pressure levels lower than optimal (efficiency&safety) for ride comfort reasons.

They recommended that you fill your tires to 90% of the max tire pressure listed on the tire sidewall (as long as that is higher than the auto manufacturer recommendations).

My Michelin PSS tires have a max pressure of 50psi, and 90% would be riding around at 45psi front and rear (9psi more than recommended by Lexus). I am trying this out now. The ride is a little firmer, but I haven't pushed the car to see if I feel a different level of grip.

What are your thoughts/experiences on this?

Last edited by Gymkata; 08-10-14 at 01:09 PM.
Old 08-10-14, 04:43 PM
  #14  
lobuxracer
Tech Info Resource

iTrader: (2)
 
lobuxracer's Avatar
 
Join Date: Jul 2006
Location: Georgia
Posts: 22,207
Received 3,849 Likes on 2,334 Posts
Default

I run 44 psi hot in the Bridgestones which turns out to be 32 psi cold. I haven't tracked the PSS yet, but I suspect they'll be similar. However, pressure on the track is very different from pressure on the street. If you want a simple and practical way to check pressure, put white shoe polish stripes across the tread, drive the car as you normally expect to drive it, and adjust the pressure until the white stripe goes away across the full width of the tire.

If you pumped up your tires as high as these guys are recommending on the track, you'd think you were on ice skates after 3 laps.
Old 08-10-14, 04:50 PM
  #15  
I8ABMR
Lexus Fanatic
 
I8ABMR's Avatar
 
Join Date: Sep 2007
Location: Waiting for next track day
Posts: 22,609
Received 100 Likes on 65 Posts
Default

I would stick with 36 cold as recommended by Lexus. Too high and you lose grip and have uneven tire wear, and to low your going to burn up the tires . If your on a track you have to check and adjust. They can go way too high.


Quick Reply: tire pressure questions



All times are GMT -7. The time now is 01:32 PM.