Wheels & Tires Forged | Billet | Cast | Radials | Slicks

Right P.S.I. for tires?

Thread Tools
 
Search this Thread
 
Old 02-16-2013, 05:37 PM
  #1  
TECH Resident
Thread Starter
 
slow ride 02's Avatar
 
Join Date: Oct 2008
Location: Anaheim Ca.
Posts: 801
Likes: 0
Received 0 Likes on 0 Posts

Default Right P.S.I. for tires?

How do you determin the correct puressure for best wear and handleing? The tires I bought (NITTO 555) only have a max P.S.I. and its 44 lbs.
Old 02-16-2013, 06:19 PM
  #2  
LS1Tech Administrator
iTrader: (3)
 
RPM WS6's Avatar
 
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,044
Likes: 0
Received 1,492 Likes on 1,074 Posts

Default

GM recommends 30psi F/R for 4th gen F-bodies. This is true regardless of tire brand.

Personally I use 32 front/30 rear. I've seen excellent wear results with these pressures and standard street driving.

These recommendations are for standard Z-rated street tires. Competition tires may vary depending on purpose and conditions.
Old 02-16-2013, 06:32 PM
  #3  
TECH Resident
Thread Starter
 
slow ride 02's Avatar
 
Join Date: Oct 2008
Location: Anaheim Ca.
Posts: 801
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by RPM WS6
GM recommends 30psi F/R for 4th gen F-bodies. This is true regardless of tire brand.

Personally I use 32 front/30 rear. I've seen excellent wear results with these pressures and standard street driving.

These recommendations are for standard Z-rated street tires. Competition tires may vary depending on purpose and conditions.
That is perfect! I just lowered the front to 32, I will do the rear next. The tire shop had them at 40. Thanks man!..
Old 02-22-2013, 03:05 PM
  #4  
Banned
iTrader: (2)
 
LS6427's Avatar
 
Join Date: May 2008
Location: South Florida
Posts: 11,291
Likes: 0
Received 11 Likes on 11 Posts

Default

Since I've had my car new in 1998, I've always kept all 4 tires at 40-42psi. Perfect wear every time and well over 15,000 miles per set. The damn Nittos last almost 20,000.

Goodyear GS-D3's in the rear 315's
nitro 555 Extreme in the front 275's

.
Old 02-22-2013, 03:11 PM
  #5  
11 Second Club
iTrader: (10)
 
sabersaw30's Avatar
 
Join Date: Mar 2006
Location: Hilliard fl.
Posts: 536
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by LS6427
Since I've had my car new in 1998, I've always kept all 4 tires at 40-42psi. Perfect wear every time and well over 15,000 miles per set. The damn Nittos last almost 20,000.

Goodyear GS-D3's in the rear 315's
nitro 555 Extreme in the front 275's

.
I agree low tire pressure wears tires out quick on the sides.I like 40psi.Look at all the wore out tires at a tire shop most of them is wore out on the sides and the middle looks new.
Old 02-22-2013, 03:22 PM
  #6  
TECH Junkie
iTrader: (9)
 
JimMueller's Avatar
 
Join Date: Jan 2002
Location: Casselberry FL
Posts: 3,964
Received 52 Likes on 43 Posts

Default

I use a probe-type pyrometer to check tire contact patch temps after a long highway drive. In the summer on [265,275]/40/17's that was around 32F/30R hot. But I haven't done it on the 315's.
Old 02-22-2013, 03:39 PM
  #7  
11 Second Club
iTrader: (5)
 
Ballzee's Avatar
 
Join Date: Feb 2012
Location: North Florida
Posts: 536
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by sabersaw30
I agree low tire pressure wears tires out quick on the sides.I like 40psi.Look at all the wore out tires at a tire shop most of them is wore out on the sides and the middle looks new.
not the way we should be driving...burn out centers baby!!!

i run my nitto DR's @ 24
Old 02-22-2013, 03:43 PM
  #8  
10 Second Club
iTrader: (41)
 
senicalj4579's Avatar
 
Join Date: Jan 2006
Posts: 5,257
Received 22 Likes on 20 Posts

Default

I shoot to have 32psi in all four when hot for street but that changes when I go to the track.
Old 02-22-2013, 04:43 PM
  #9  
TECH Senior Member
iTrader: (35)
 
99Bluz28's Avatar
 
Join Date: Nov 2007
Location: C. V., Kalifornia
Posts: 9,705
Likes: 0
Received 11 Likes on 11 Posts
Default

I normally run 32/30 psi and have a even wear pattern.
Old 02-23-2013, 09:43 AM
  #10  
TECH Junkie
 
NC01TA's Avatar
 
Join Date: Aug 2006
Location: Western North Carolina
Posts: 3,585
Received 443 Likes on 320 Posts

Default

Always 30 psi to 32 psi here and very even wear since the car was new.
LS6427, I would think having 40 psi in these tires would cause a really harsh ride. No??? Any excessive wear in the middle tread area?? You are 10 lbs over recommended. I know your set-up is modified but if I had 40 psi in my GS-D3's I would be wearing them out. Currently have 14,000 miles on them and 20,000+ is almost certain.
Old 02-23-2013, 04:50 PM
  #11  
LS1Tech Administrator
iTrader: (3)
 
RPM WS6's Avatar
 
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,044
Likes: 0
Received 1,492 Likes on 1,074 Posts

Default

Originally Posted by sabersaw30
I agree low tire pressure wears tires out quick on the sides.I like 40psi.Look at all the wore out tires at a tire shop most of them is wore out on the sides and the middle looks new.
30-32psi is not "low", it's the OEM recommended pressure for these cars with stock tire sizes, and if that PSI is properly maintained you will see even wear at a normal rate on a Z-rated street tire. What often happens is that people don't bother to check the pressure often enough and PSI drops well below the recommended rating, especially when cooler weather comes.

I've got 30k miles on the current set of BFG KDWSs on my '02, and the wear pattern is perfect....plus a good bit of tread still remaining. I've maintained a constant 32F/30R PSI in these tires at all times. They are going to wear out from age/dry rot before running out of tread.
Old 02-23-2013, 05:25 PM
  #12  
TECH Enthusiast
iTrader: (3)
 
US_Army_Z28's Avatar
 
Join Date: Mar 2011
Location: Gaffney, S.C.
Posts: 559
Likes: 0
Received 0 Likes on 0 Posts
Default

I run with 38 in all 4, I maintain regular tire rotations and after 20k miles all 4 tires are at 7/32's tread depth both in the center and on the sides as long as you don't go below 32 or above 40 tires should wear relatively even go above 42 or so and you'll start seeing increased wear in the center, go below 30 and you'll be wearing out the sides. Between 32 and 40 is the sweet spot for daily driving
Old 02-24-2013, 12:11 PM
  #13  
LS1Tech Administrator
iTrader: (3)
 
RPM WS6's Avatar
 
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,044
Likes: 0
Received 1,492 Likes on 1,074 Posts

Default

30psi (cold) is the factory recommendation and will NOT cause significant uneven wear during typical daily driving on regular street tires in the factory sizes unless you have an issue with steering/suspension components or have made significant changes to weight/weight distribution. Again, uneven wear (that isn't due to steering/suspension issues) comes from a failure to maintain this recommended pressure. If you set it at 30psi in July and then don't check it again until spring, it will probably have dropped to 26psi or lower in a cold climate over the winter.

32psi up front will help to compensate for the uneven weight distribution, and would be even more helpful if you have added extra weight to the front (such as an iron block, supercharger kit with associated parts, etc.)

30psi in the rear should be ideal at stock weight, but if you're carrying a heavy load out back then you may want to raise the rears to 32psi as well.

I've seen an excellent wear pattern over the last 30k miles on my current tires which have been consistantly maintained at 32F/30R (cold).
Old 02-24-2013, 12:22 PM
  #14  
TECH Senior Member
iTrader: (8)
 
Blackpanther99's Avatar
 
Join Date: Sep 2012
Location: Baytown, TX
Posts: 6,963
Received 4 Likes on 4 Posts

Default

Good information^ I have always used 32psi up front and 30psi on the rear tires.
Old 02-24-2013, 01:14 PM
  #15  
TECH Enthusiast
iTrader: (3)
 
US_Army_Z28's Avatar
 
Join Date: Mar 2011
Location: Gaffney, S.C.
Posts: 559
Likes: 0
Received 0 Likes on 0 Posts
Default

Hence why I said that below 30 will start to cause uneven wear, I said I wouldn't go below 32 earlier in the post simply bc I've noticed my handling, traction in inclimate weather and fuel economy are slightly better in the 35-38 range.
Old 02-25-2013, 02:51 PM
  #16  
TECH Senior Member
iTrader: (8)
 
Blackpanther99's Avatar
 
Join Date: Sep 2012
Location: Baytown, TX
Posts: 6,963
Received 4 Likes on 4 Posts

Default

^How does it ride? What MPG changes have you noticed compared to a 32psi or lower?
Old 02-25-2013, 03:09 PM
  #17  
TECH Enthusiast
iTrader: (3)
 
US_Army_Z28's Avatar
 
Join Date: Mar 2011
Location: Gaffney, S.C.
Posts: 559
Likes: 0
Received 0 Likes on 0 Posts
Default

At 38 compared to 32 my highway mpg went from 16.7 to 18.3. and does seem to ride smoother as well
Old 02-25-2013, 04:34 PM
  #18  
LS1Tech Administrator
iTrader: (3)
 
RPM WS6's Avatar
 
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,044
Likes: 0
Received 1,492 Likes on 1,074 Posts

Default

In my personal experience, I've always noticed a harsher ride with higher PSI.
Old 02-25-2013, 05:51 PM
  #19  
11 Second Club
iTrader: (10)
 
sabersaw30's Avatar
 
Join Date: Mar 2006
Location: Hilliard fl.
Posts: 536
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by RPM WS6
30-32psi is not "low", it's the OEM recommended pressure for these cars with stock tire sizes, and if that PSI is properly maintained you will see even wear at a normal rate on a Z-rated street tire. What often happens is that people don't bother to check the pressure often enough and PSI drops well below the recommended rating, especially when cooler weather comes.

I've got 30k miles on the current set of BFG KDWSs on my '02, and the wear pattern is perfect....plus a good bit of tread still remaining. I've maintained a constant 32F/30R PSI in these tires at all times. They are going to wear out from age/dry rot before running out of tread.
Good point on checking tire pressure often.My tires are usually 40 when hot cold is around 36.I just like how the car feels so much less rolling resistance.Deffinately feel the bumps.Now my nitto 555rs like around 25 for a whole lot more rolling resistance.

Last edited by sabersaw30; 02-25-2013 at 05:57 PM.
Old 02-26-2013, 04:52 AM
  #20  
TECH Enthusiast
iTrader: (3)
 
US_Army_Z28's Avatar
 
Join Date: Mar 2011
Location: Gaffney, S.C.
Posts: 559
Likes: 0
Received 0 Likes on 0 Posts
Default

I will agree at some times if I'm driving around these shitty *** city and county roads we have around here higher psi will make for a rougher ride, but 90% of my driving is done on the highway so it rarely is an issue and on smooth highway it rides amazing so where you do the majority of your driving is another thing to consider simply to make a more comfortable ride for yourself. Thanks for sayin tht rpm wouldn't have even thought about the condition of the road you drive on if it wasn't for that post. Brain fart on my part lol


Quick Reply: Right P.S.I. for tires?



All times are GMT -5. The time now is 08:40 AM.