Tire Pressure
------------------------------
Date: Mon, 24 Mar 97 14:58:32 PST
From: barney@flowpoint.com (Barney McNamara)
Subject: How low do you go?
To: Toy4x4@tlca.org
I just got back from a short trip to Pismo Beach, my son was in a surf contest
down there, so I went along with the truck for a little cruising in the dunes.
I was a little disappointed in the traction from my new BFG All Terrains. They
are 31x10.50's on 15x8 wheels. The old tires were Uniroyal Laredos, also
31x10.50's. The old tires were worn, so I replaced them and my wheels a while
ago. I remember the first trip, I took the Uniroyals down to 12 lbs, and they
seemed to get me around OK. This trip, I took the BFG's down to 15 lbs, and
had a hell of a time getting up the dunes. I didn't want to let more air out,
to prevent them from coming off the rims. I normally run these at 38 lbs on the
street.
How low do you people take your tires?
I'm wondering if the stiff sidewalls on the BFG's hold up the tires too much,
reducing the traction in soft stuff. Any comments on the traction of BFG's
in sand?
The BFG's at 38 lbs seem to work great on the street. The old tires slipped
on wet streets, which is where I spend most of my time in the truck. I got
the BFG's because they seem so common, I figured they must be good tires.
Maybe they are just good road tires like the new Tacos/4Runners are good road
living rooms?
_____________________________________________________________
Barney McNamara 83 Toyota Short Bed
( barney@flowpoint.com ) stock 22R motor ; 3" body lift
Santa Cruz, Ca. 8" alloy rims; 31" BFG A/Ts
____________________________________________________________________
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Date: Mon, 24 Mar 1997 21:23:56 -0800 (PST)
From: Chris Geiger
Subject: How low do you go?
To: Toy4x4@tlca.org
> How low do you people take your tires?
I run 10 LBS in my 4runner tires. I have used this for years in tires from
31 - 33". It works great. I run the sand at pismo most every month. Check
out the pics on my web site. http://home1.gte.net/cgeiger/offroad.html
Chris Geiger
PS no sliding sideways with lo psi !
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Date: Wed, 26 Mar 97 09:02:48 PST
From: barney@flowpoint.com (Barney McNamara)
Subject: How low do you go?
To: Toy4x4@tlca.org
Without power steering, I would need gorilla arms to turn the steering
wheel in parking lots at less than 25 lb. After 5,000 miles on my new
BFG AT's at 35 lbs, they looked a little worn on the outsides, so I
increased my street pressure to 38 lb. I can only get my truck to 75 mph
downhill with the wind, and if it hops, I'm in hog-heaven. I do get
about 18+ mpg in my combined freeway/town driving. The odometer only
gives me 16.4 mpg, but with the 31 inch tires, I know I'm going 10-15%
further than it measures. So I round it up to 18 mpg. The low pressure
driving is only off road where the slow speeds, 4 wheel drive, and other
extra forces combined with the generally short distances make mpg hard to
measure. I know it's not much, I generally forget to fill up before I get
to the trail head, then get nervous about running out while I'm out. I do
carry a 5 gallon can mounted on my bumper if I'm going very far off road.
With the stock square black bumper, and the 3" body lift, I can mount the
bracket on top of the bumper and still open the tailgate without the can :-)
>I know where you stand on that at high psi. Tis why I run med psi. The
>rear axle hops on this one rough road at about 75 mph.
>>
>> I have run around 25 in my stock 31x1050 and can fell the added friction.
>> So is your fuel economy out the door?
>> Steve C.
>>
_____________________________________________________________
Barney McNamara 83 Toyota Short Bed
( barney@flowpoint.com ) stock 22R motor ; 3" body lift
Santa Cruz, Ca. 8" alloy rims; 31" BFG A/Ts
______________________________________________________________
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Date: Wed, 26 Mar 97 12:53:00 MST
From: chott@aicd.sps.mot.com (Jim Chott)
Subject: How low do you go?
To: toy4x4@tlca.org
>How low do you people take your tires?
>
>I'm wondering if the stiff sidewalls on the BFG's hold up the tires too much,
>reducing the traction in soft stuff. Any comments on the traction of BFG's
>in sand?
I have taken my 32" BFG Muds down to 5-6psi in cinders and sand. I wouldn't
want to have to turn fast at that pressure though. On rock crawling stuff,
I just had mine down to 12psi last weekend. With lots of weight on two
tires, the rim comes pretty close to the tread. At the lower pressures,
the sidewalls seem to flex pretty easily. I have had decent luck with the
Muds in sand and cinders, but have not run other tires to compare to.
Jim Chott
rzaa80@email.mot.com
1985 4Runner, lots of mods
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------------------------------
Date: Thu, 27 Mar 1997 00:31:16 -0500
From: Kevin Watters
Subject: tires
To: toy4x4@tlca.org
> I'm wondering if the stiff sidewalls on the BFG's hold up the tires too much,
> reducing the traction in soft stuff. Any comments on the traction of BFG's
> in sand?
>
> The BFG's at 38 lbs seem to work great on the street. The old tires slipped
> on wet streets, which is where I spend most of my time in the truck. I got
> the BFG's because they seem so common, I figured they must be good tires.
> Maybe they are just good road tires like the new Tacos/4Runners are good road
> living rooms?
> _____________________________________________________________
> Barney McNamara 83 Toyota Short Bed
> ( barney@flowpoint.com ) stock 22R motor ; 3" body lift
> Santa Cruz, Ca. 8" alloy rims; 31" BFG A/Ts
> ____________________________________________________________________
>
I run 32.11.50-15's (BFG'S)on the street on 15x8 wheels and run 24lbs
in the front and 22 in the rear when unloaded and still don't get a full
contact patch. Any more pressure and I feel like I am going to bounce
off the road. I drop to 10 to 15 lbs unloaded offroad and don't notice
much sidewall flex, those three ply sidewalls are tough! I cannot
complain about the traction until I get into the mud and then I plan on
using my buckshot mudders to get me there ( great sidewall flex by the
way) I'm not much help to you but that's my story and I'm sticking to
it.
------------------------------
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Date: Thu, 27 Mar 1997 19:22:22 -0700
From: "Colin Learning"
Subject: How low do you go?
To:
I have 33" Yokohama Mud Diggers on 15x10 steel wheels. This is my third
set and I have finally got them to wear properly. In my case, around town
I run 15psi in the fronts and 10psi in the rear. Off road I air down to
4-5-psi up front and 2-3psi in the rear. I found this to work great as the
truck can't go over 80KM anyways and I have never had a tire come off a
bead (touch wood). If I do have to go on the highway for a long trip I
might air up to 20psi.
Colin Learning
clearning@ccinet.ab.ca
85 Toy X-Cab, 4.3 LT.,ARB front, LSD rear
33" Yokohama Mud Diggers
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------------------------------
Date: Fri, 4 Apr 1997 08:39:10 -0800 (PST)
From: Chris Geiger
Subject: helloooooo
To: Toy4x4@tlca.org
> also when i run the beaches up here, should follow the old rule of letting
> out the air, and to what level dost thou recommend?
> Wind The Frog !!!
The larger the tire the lower you can go. I found when running 33's I can
get down to 9 lbs but when I was running 31's I would use about 12 lbs.
the wider the rim the more air you need to keep the tire on the rim. At
these low pressure you can't make quick turns or give it lots of gas in a
turn to spin the tires, nut for climbing dunes low is the way to go. I
allays carry a low pressure gauge (0-20 lbs) that I got at k-mart for $5.
normal gauges can't read that low with any accuracy. I use a valve stem
remover to remove the core because I hate to wait for the air to come out.
Christopher A. Geiger Voice 805-893-4044
Technical Operations Manager Fax 805-893-8758
UCSB MicroComputer Laboratory http://geiger.mcl.ucsb.edu/index.html
------------------------------
------------------------------
Date: Thu, 15 May 1997 07:07:25
From: Ed Ruf
Subject: resurrecting the dead preload horse
To: Toy4x4@tlca.org
Just wanted to point out that what we subjectively refer to as "ride"
is governed by a VERY complex interaction of several systems and
components. That diatribe of mine is still a fairly simple description o
things and leaves out many additional complexities.
One that I think needs to be addressed if we are discussing "ride" is
tires. Effectively your tire is it's own suspension system, with it's
own set of characteristics, between the one fixed point in the problem,
e ground, and the rest of everything. This is also the one we have some
real (and cheap) control over. Air pressure is a wonderful tool when
used properly. We all air down when we do serious wheelin', but you can
tune the ride a bit for given known situations to your benefit. I run
lower pressures by a couple #'s for the daily driving, but up them from
the long trips up to NY that I take several times a year. The truck is
more loaded then and I'm going to be doing highway cruising. But, If
you've ever been on the Brooklyn-Queens or Cross-Bronx expressways,
then you also know this can be more like high speed desert wheeling
than one might imagine.
If you haven't tried experimenting with your air pressure on a routine
basis, give it a try. You'll learn how your particular setup will
respond, and reap the benefits that are there to be had. And hey, air
is the cheapest fluid you can put in your rig.
Ed
------------------------------
------------------------------
Date: Tue, 17 Jun 1997 16:48:07
From: Charles
Subject: Toy4x4 Digest V1 #311
To: Toy4x4@tlca.org
At 01:20 AM 7/17/97 -0500, you wrote:
>i have 15X8 eagle alloys on with a standard offset with 32X11.5's with a
>nwor 2" torsion bar lift and rubbing on the left side as full compression
>while turning left but i hammered the back part of he wheel well flat and
>that fixed that. By the way this is on a 93 v6 xtra cab with no front
>valance.
>
>Q: i am wanting taller tires (33 or 35's) and wanted to know if anybody
>has tried to run a 33x10.5 on a 8" wide wheel with the same lift.
>such tires as a PR buckshot radial or a 33X10.5 or 33X11.5 swamper
>thornbirds or tsl radials.
>
>thanks in advance
>
>aaron bewley
When i first bought my 33X12.50's I ran them on the 8" rim I used for my
31X10.50's. It works fine, and actually protects the rim from damage
because of the larger sidewall bulge. Be carefull not to run them with
too little pressure though, They will lose a bead easier than if they
were on a 10" rim. When I used the 8" rim i never went below 15psi.
Charles Brooks
cbrooks1@mail.acilink.net
------------------------------
Date: Thu, 17 Jul 1997 23:43:33 -0400 (EDT)
From: DRM033@aol.com
Subject: Toy4x4 Digest V1 #311
To: Toy4x4@tlca.org
In a message dated 97-07-17 21:19:19 EDT, you write:
<< . Be carefull not to run them with
too little pressure though, They will lose a bead easier than if they
were on a 10" rim. When I used the 8" rim i never went below 15psi.
>>
uh, that is backwards. the narrower rim allows lower preasure to be run.
there is an increased chance of rolling it off the rim on a sidehill, but
unlikely.
David
DRM033@aol.com
------------------------------
Date: Thu, 17 Jul 1997 21:53:35 -0700
From: Brandon Miller
Subject: Toy4x4 Digest V1 #311
To: "Toy4x4@tlca.org"
DRM033@aol.com wrote:
>
> In a message dated 97-07-17 21:19:19 EDT, you write:
>
> << . Be carefull not to run them with
> too little pressure though, They will lose a bead easier than if they
> were on a 10" rim. When I used the 8" rim i never went below 15psi.
> >>
>
> uh, that is backwards. the narrower rim allows lower preasure to be run.
> there is an increased chance of rolling it off the rim on a sidehill, but
> unlikely.
>
> David
> DRM033@aol.com
I ran 3psi on my swampers and I run my new 35 bfg mudders at 7 and they
hardly bulge on my 10" aluminum rims... I have never popped a bead
- --
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Brandon Miller email: sac78483@saclink.csus.edu
Sacramento, CA millerb@gaia.ecs.csus.edu
url: http://gaia.ecs.csus.edu/~millerb/4x.html
1983 Toyota LB locked F&R, 5.29:1 gears, roll cage, etc. etc.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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Date: Sun, 20 Jul 1997 18:13:36 -0400 (EDT)
From: DRM033@aol.com
Subject: wheel Size
To: Toy4x4@tlca.org
In a message dated 97-07-19 06:15:12 EDT, you write:
<< whitespokes work well for now, but I want beadlocks eventually. ihave
read stories of dirt-ttack and SCCA guys of using shhet-metal screws as
cheap beadlocks...who knows?
-Wiley davis- >>
I have a friend who used screws in his rims. I am not sure if they were made
for bead locks, but they looked like sheet metal screws. Anyway, he ended up
snapping one of the screws in half and had a flat on the trail.
by the way, these were 44" Groundhawgs under a Suburban.
The secret is to get the screws just the right length so they don't go all
the way through the tire.
David
DRM033@aol.com
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Date: Sun, 20 Jul 1997 23:56:13 -0500
From: Chris Caldwell
Subject: Tire Psi
To: 4x4 digest
I've read a few posts of late that have talked of trail psi's and was
wondering if anyone could share their experiance with 31x10.5x15's
mounted on 7 inch wheels.
Thanks,
Chris Caldwell
caldwell@vol.com
------------------------------
Date: Sun, 20 Jul 1997 20:54:41 -0700
From: Scott Wilson
Subject: Tire Psi
To: Toy4x4@tlca.org
Chris Caldwell wrote:
>
> I've read a few posts of late that have talked of trail psi's and was
> wondering if anyone could share their experiance with 31x10.5x15's
> mounted on 7 inch wheels.
I had the 31", 7" setup up until last week. I was happiest running
15psi on the trail, and 10psi in sand.
Scott
- --
_____
/_/_|_\__ Scott Wilson
| _ _ : Santa Clara, CA
*/_\---/_\' http://www.scruz.net/~barneym/scott
(_) (_)
~~~~~~~~~~~~~~~~~~~
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Date: Sun, 20 Jul 1997 21:45:00 -0700
From: Brandon Miller
Subject: Tire Psi
To: Toy4x4@tlca.org
Chris Caldwell wrote:
>
> I've read a few posts of late that have talked of trail psi's and was
> wondering if anyone could share their experiance with 31x10.5x15's
> mounted on 7 inch wheels.
>
> Thanks,
> Chris Caldwell
> caldwell@vol.com
Depends on the tire, air down till they bulge, anywhere from 5-15psi
- --
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Brandon Miller email: sac78483@saclink.csus.edu
Sacramento, CA millerb@gaia.ecs.csus.edu
url: http://gaia.ecs.csus.edu/~millerb/4x.html
1983 Toyota LB locked F&R, 5.29:1 gears, roll cage, etc. etc.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
------------------------------
Date: Sun, 20 Jul 1997 21:14:56 -0800
From: "CONRAD"
Subject: Tire Psi
To:
> From: Chris Caldwell
> Subject: Tire Psi
> Date: Sunday, July 20, 1997 8:56 PM
> I've read a few posts of late that have talked of trail psi's and was
> wondering if anyone could share their experiance with 31x10.5x15's
> mounted on 7 inch wheels.
I have seen as low as 3 psi in snow (driving very carefully to keep the
bead seated), and down to 5 psi in rocks, once again driving very
carefully. At 10 psi in just about any terrain you are pretty safe.
jc
Jack Conrad, BIG TOY, TLCA # 3851,conrad@mosquitonet.com, North Pole, AK
84 FJ-60, coils over leaf-over, 350,38s, ARB
69 FJ40, 79 FJ40, both stock
92 Extra-Cab, coils over leafs, 5.29s, ARB, 35s
Land Cruiser, don't leave the pavement without one!!
------------------------------
Date: Sun, 20 Jul 1997 22:14:01 -0700
From: Wiley Davis
Subject: Tire Psi
To: Toy4x4@tlca.org
I have the 31's on my tacoma, 7" wheel. I usually drop to 20psi for
fireroads/pre-running, 5psi for crawling/sand running. No problem
keeping them on the wheels...even in the sand.
- -Wiley davis-
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Date: Mon, 21 Jul 1997 12:52:20 -0600
From: gwking@senior-express.com (Gene W. King)
Subject: Tire pressure 31x10.50x15
To:
I don't know in what part of the country you are but here in Colorado I
generally air down to @ 20psi ,depending on the condition of the trail. If
it's really rocky going, I'll air down to @12 - 15 psi. But the thing to
keep in mind, at least out here, is the elevation climb. If you start @ 20
psi at @8000 ft., you could be back upto @25 - 30 at 10,000 - 12000 ft. I
have ARB in the rear with an air hose fitting so I can air up again without
driving long distances on pavement.
Hope that helps.
Gene W. King
------------------------------
Date: Mon, 21 Jul 1997 09:55:53 -0700
From: "John D. Foster"
Subject: Tire Psi
To: Toy4x4@tlca.org
Chris Caldwell wrote:
>
> I've read a few posts of late that have talked of trail psi's and was
> wondering if anyone could share their experiance with 31x10.5x15's
> mounted on 7 inch wheels.
It depends largly on the particular tires used, the load or weight of
the vehicle, and also the terrain you're wheeling in. Could be anywhere
from 0-15 lbs.
- --
John D. Foster mailto:jidd@mindless.com
Home Page (updated) http://www.psnw.com/~jd/
Toyota Member List http://www.psnw.com/~jd/toy4x4list/
1991 GMC S-15 Jimmy 4.3 V6
Toyota Axels, TH350, NP205
------------------------------
Date: Mon, 21 Jul 1997 17:00:54 -0400 (EDT)
From: DRM033@aol.com
Subject: Tire Psi
To: Toy4x4@tlca.org
In a message dated 97-07-21 01:13:16 EDT, you write:
<< have seen as low as 3 psi in snow (driving very carefully to keep the
bead seated), and down to 5 psi in rocks, once again driving very
carefully. At 10 psi in just about any terrain you are pretty safe.
jc >>
I would stay around 15 to 22 psi. In the South, I have found that this
offers a good compromise between loss of ground clearance and sidewall flex.
I need all the clearance I can get for those mud holes.
David
DRM033@aol.com
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Date: Thu, 24 Jul 1997 10:26:29 -0700
From: Scott Wilson
Subject: BFG's ATs Cupping
To: Toy4x4@tlca.org
Rosenberger Bud wrote:
> The cupping issue does make me ask another question tho. What tire
> pressures are folks running with oversize tires on the road and how do
> you know if it is enough/too much other than wear?
You're gonna have nothing but variation if you poll people to find their
pressure and results. Every model of tire will wear differently, and at
different pressures, due things like variations in size from manufacturer to
manufacturer, different tread patterns, hardness of rubber compounds and
stiffness of sidewall. Not to mention all the different size rims we're all
driving on.
Finding the right pressure for your tire/wheel combo may take a little time.
Vary the pressure and find where you like it best, and where it appears the
tire is sitting properly on the road. Then pay attention to how they wear.
You may even want to wash off the tread and drive it a couple of miles. It
should be pretty obvious if you're driving on the whole tire, or just the
center after doing that. (because you'll be able to see the dirt on the tread
you drive on)
I've had my tires (32" MT's on 7" rims) for over a week, and I still haven't
gotten it "right." I drove out of the shop on 32 lbs of pressure, it rode
great, but I was basically riding on the center of the tread at that pressure.
I've got it down to 26-27 lbs now, and it's -almost- sitting flat. I think
I'm gonna end up running 27 in the front, and 25 in the back.
As you can see, finding the right pressure may take a little trial and error,
and the results may be very specific to your truck.
YMMV,
Scott
- --
_____
/_/_|_\__ Scott Wilson TLCA #5261
| _ _ : 88 4Runner SR5 V6
*/_\---/_\' Santa Clara, CA
(_) (_) http://www.scruz.net/~barneym/scott/
~~~~~~~~~~~~~~~~~~
------------------------------
------------------------------
Date: Fri, 26 Sep 1997 16:50:13 -0000
From: runars@isbank.is
Subject: Tire Pres.
To: Toy4x4@off-road.com
There is just one rule for tire pressures, and it is to use the correct
one... ;-))
It is common misunderstanding that air pressure carries the weight of
your truck. It is actually the volume of the air inside the tire that
carries the weight, regardless of the size of the tire. It takes, say X
cubics of air, to hold up your truck. The same X cubics are needed if
you're riding 235's or 44's. However the X cubics will cause a lot more
pressure inside the small 235 than inside the huge 44".
Correct pressure is therefore depended on size and load on a tire.
Generally speaking that should be somewhere inbetween 20 and 40 psi, for
street use. I'm riding on 38x15.5 tires, and have 25 psi up front, and
20 psi in the rear. When I go out of the pavement I drop them down to
12/10 psi, and when in deep snow one goes down to 1-2 psi front and
rear.
Also radial tires and belted tires, are less sensitive to pressure than
diagonal tires are. Diagonal tires need adjustments for the slightest
change in load, if maxium wear and traction is req.
My personal rule is to save the tires when driving on the pavement, and
save the truck when off it...
Cheers, Runar.
-------------------
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Date: Thu, 18 Dec 1997 15:24:36 -0800 (PST)
From: Jonathan Albrecht
Subject: Toy4x4 Digest V1 #599
To: Toy4x4@tlca.org
> >36" swampers at 8-10 psi is NOT airing down for snow use.
> >Runar. (uses 10psi for summertime driving, and yes I have rancho
> >5000....) For fresh snow 4 psi is the maxium press, 2.5 psi is more
> like it.
I'm running 35x12.50 bfg muds on 15x10's (on a mostly stock 4runner),
and I'm kinda curious what pressure others with a similar setup are
running on the highway. I checked mine after the shop put them on, and
they were at 35psi! Seemed like way to much, so I dropped it down to
about 25 or so. It seems to be fine, but heck, it seemed fine at 35
too. I haven't tried the chalk or 'drive through a puddle and look at
the tracks' methods yet (too lazey).
Also, how low do you think I dare go offroad (for real slow stuff). I
don't have an aircompressor, or a fullsize spair, so I'm a little
nervous about running too low, especially with the 10" wide wheels. I
tried running it at about 17 for awhile, and it seemed fine (still feels
safe on the highway too), but I'm curious how low I can really go.
_______
Jonathan Albrecht __. /_/__|__\__
albr9619@uidaho.edu __/__|\___ |_.--.__,--;
http://www.uidaho.edu/~albr9619 :--.__|.--.|,---- ~'(__)'`(__)
`'`'`''`'`'`''``'`'`'`'`''`'`'``'`
------------------------------
Date: Thu, 18 Dec 1997 15:41:37 -0800 (PST)
From: Chris Geiger
Subject: Toy4x4 Digest V1 #599
To: Toy4x4@tlca.org
You will get better gas mileage and longer tire ware with the higher
pressure and 35PSI will work well with the 10" wide wheels. At low
pressure (below 12) you may have problems with the tire coming off the
rim. When I had 33 X 12.50 BFG muds on 8" wheels I ran them as low as 8
PSI in the sand. I would keep the minimum trail to gas station pressure
at about 10 PSI.
Chris Geiger 93 4Runner http://geiger.mcl.ucsb.edu/offroad.html
> I'm running 35x12.50 BFG muds on 15x10's (on a mostly stock 4runner),
> and I'm kinda curious what pressure others with a similar setup are
> running on the highway. I checked mine after the shop put them on, and
> Also, how low do you think I dare go offroad (for real slow stuff). I
> don't have an air compressor, or a full size spare, so I'm a little
------------------------------
------------------------------
Date: Mon, 11 Aug 1997 11:08:34 -0400
From: john skaggs
Subject: Tire Pressure for 32's
To: Toy4x4@tlca.org
> What's the best tire pressure (on-road) to run for BFG A/T 32x11.50's
> on 15x7 stock SR5 rims.
> Thanks,
> Deo F.
Nobody knows for sure, but you can find out, First find a place that is
paved where there is no traffic so that you can drive in a straight line
and stop whenever you want to, then take a grease pencil and draw a line
across the tread of your tires. Then I would start with 35psi drive
straight a little while then get out and see where the line is worn off
the tire, if it is just a little then let out 5psi and drive it again
and check it again, do this until the line is evenly worn off of your
tire. You have to go straight though so that you don't scrub off the
line on the sides around a corner.
Anybody else have a better way?
John Skaggs
TLCA# 5560
85 4Runner (gettin taller soon) You know the story
Akron, Ohio
John.Skaggs@ab.com
------------------------------
Date: Mon, 11 Aug 1997 10:21:02 -0800
From: "CONRAD"
Subject: Tire Pressure for 32's
To:
If the line is only scrubbed off of the center of the tread you are over
inflated. If the center is still there and it's off of the outer edges you
are under inflated.
jc
Jack Conrad, BIG TOY, TLCA # 3851,conrad@mosquitonet.com, North Pole, AK
84 FJ-60, coils over leaf-over, 350,38s, ARB
69 FJ40, 79 FJ40, both stock
92 Extra-Cab, coils over leafs, 5.29s, ARB, 35s
Land Cruiser, don't leave the pavement without one!!
------------------------------
------------------------------
Date: Tue, 10 Mar 1998 06:46:34 -0700
From: Nick.Krest@nickkrest.batnet.com (Nick Krest)
Subject: 32x11.50's on Stock 7" Wheels - She's gonna' be mad!
To: Toy4x4@tlca.org
Dave Booth wrote:
"...32x11.50's on stock 7" alum wheels...I noticed
that the outer and inner 1" of tread isn't touching
the pavement...at 28 psi cold...how low could I
safely go?"
I don't know where everyone got this hang-up that we have to run our tires
at the manufacturer's maximum recommended pressure. It simply isn't true.
You're running an oversized load range C tire, probably good for about 1250
pounds per of load, on a light truck that weighs about 3100 pounds (unless
you're hauling large cauldrons of lead to boil me in). The tires still have
way too much pressure in them, IMHO.
Tire pressure should reflect the application, not just the manu's load
limit. I've been running a street pressure of 24psi front and 20 psi rear
for 11 years on my 33/12.5's. They go down to 8-14psi offroad, depending
upon application. "Fine," you say, "but you have 12.5's on 8.5" rims. My
rims are 1.5" narrower." To which I would say, "You must compensate for a
number of factors in finding your ideal tire pressure." I certainly
wouldn't be concerned about popping a bead until you got into the low teens
on pressure. I would imagine you could go as low as 22psi front, 20psi rear
and still maintain a high psychological comfort level.
For example, I'm running 205/50-15's on 6.5" rims on my Miata. How much
pressure would you think I'm running for street and autocross use? 36? 32?
Try 26psi all around. I routinely set the tire pressure in my motorcycles
to 15psi front, 13psi rear.
The point I'm trying to make is that your world is not going to end if you
drop below the mfr's listed maximum pressure, or even below the pressure
listed in the owner's manual, ESPECIALLY if you're running oversized tires.
Experiment. Live a little. Pressurized air is virtually free, and it's
certainly a great way to spend your copious amounts of free time. Imagine
this Saturday: Beautiful weather, your better half is clamoring for your
attention, and asks "What do we have planned for today?"
"Baby," you say, "we're going to spend the day testing different tire
pressures in my truck, and see how they reflect upon a number of factors,
including tire wear, footprint, handling, and comfort level."
What girl wouldn't just melt?
Good luck,
- Nick
------------------------------
Date: Tue, 10 Mar 1998 08:39:37 -0800
From: Dan Merrick
Subject: 32 X 11.50 on 7" Wheels
To: Toy4x4@tlca.org
I ran 31" X 11.50" Yokohama Superdiggers on 7" wheels. I got about 60K
miles out of the tires, and probably could have squeezed a few thousand
more out of them. My secret was running the pressure at about 22 to 26 psi,
and rotating every 3K to 5K miles. The pressure sounds low, but it worked
well. Stock tire pressure is 26 psi front and 29 psi rear (I think), and
that is for the puny stock tires. The 32 X 11.5 tires have a much higher
volume of air, which helps the tire run cool, even at fairly low pressures.
Also, the sidewalls are probably very sturdy on your new 32 X 11.5's, which
helps support the weight of the vehicle at lower pressures. Try running
lower pressure, like 25 psi or so. I'm sure this will put all of your tire
on the road, and still give you good handling and mileage. 30 psi is way
too much in my opinion. The sidewall of your new tires probably shows the
tire weight capacity as something like 3000 lbs...for each tire(at max
pressure!) You are only supporting about 1000 lbs per tire, therefore don't
need lots of pressure.
Dan
------------------------------
------------------------------
Date: Tue, 10 Mar 1998 16:57:03 -0800
From: Scott Wilson
Subject: 32x11.50's on Stock 7" Wheels - She's gonna' be mad!
To: Toy4x4@tlca.org
David Booth wrote:
>
> After reading through the archives and posting an inquiry concerning
> putting 32x11.50's on stock 7" alum wheels, I decided to go for it.
> 1) Run them the way they are and accept the fact that they are going to
> wear out in the centers long before the edges do. Maybe lower the
> pressure even more? If so, how low could I safely go?
I've been running my 32x11.5 MTs on 7" rims for somewhere around 8-9
months now. I drive HARD on them, on and off pavement. I run them at
32 psi, and rotate them every other oil change. My tires are wearing
fast since I drive so hard on them, but they are wearing very evenly.
I recommend keeping them at an air pressure so that the entire tread is
touching ground...and rotating them often. I don't think you need to
invest any more money to keep them wearing correctly.
Scott
- --
_____
/_/_|_\__ Scott Wilson
| _ _ : Santa Clara, CA
*/_\---/_\' http://www.off-road.com/~swilson
(_) (_)
~~~~~~~~~~~~~~~~~~~
------------------------------
Date: Tue, 10 Mar 1998 21:28:12 -0500
From: schein@juno.com (Dan Schein)
Subject: 32x11.50's on Stock 7" Wheels - She's gonna' be mad!
To: toy4x4@tlca.org, dfbooth01@worldnet.att.net
After reading through the archives and posting an inquiry concerning
putting 32x11.50's on stock 7" alum wheels, I decided to go for it.
They went on my '89 (IFS) 4Runner last Saturday, and now I'm beginning
to wonder if I made a mistake. The ATs looks great and fit without
rubbing, although I haven't really tested the wheel travel yet, but
today I noticed that the outer and inner 1" of tread isn't touching the
pavement. No problem, I thought, I'll just lower the pressure to about
30 psi and they should ride flatter. When I got home I let the tires
cool down and then checked the pressure. Much to my surprise, they were
sitting at 28 psi cold. Now here are my choices...
1) Run them the way they are and accept the fact that they are going to
wear out in the centers long before the edges do. Maybe lower the
pressure even more? If so, how low could I safely go?
David go lower in pressure! I've run as low as 10 PSI in 33x12.50's on
10" rims when off road.
With that said let me say what you need to be concerned with is the
weight of your 4-runner (empty & loaded). Check the max rating on your
tyres sidewall and the PSI required to obtain it. Adjust this by the
actual weight of your 4-runner and adjust air to match.
- -Dan
- --
Dan Schein Esq. -=- schein@juno.com -=- Reading, PA USA
http://www.geocities.com/MotorCity/Garage/1978
Member of TLCA (#6687) and the Keystone Cruisers chapter
Proud owner of Jo, a 1978 Fj40 Toyota LandCruiser
86 Hilux, 73 Hurst/Olds, 88 Honda Civic, 93 Pontiac Transport
_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]
------------------------------
Date: Wed, 11 Mar 1998 00:49:06 -0700
From: Brian Rishaw
Subject: 32x11.50's on Stock 7" Wheels - She's gonna' be mad!
To: Toyota 4x4 Digest-posting
> 1) Run them the way they are and accept the fact that they are going to
> wear out in the centers long before the edges do. Maybe lower the
> pressure even more? If so, how low could I safely go?
David Booth:
Chris was right in his response to rotate your new 32's on 7" wheels
every 5K miles or so (I rotate mine every oil change - 5K miles), but
you should decrease your tire pressure accordingly (fronts might differ
from the rears) until the entire tread width is in contact with the
ground. This will not only give you your best tire wear and thus
longest tread life, but it's for safety reasons also. You've increased
your rolling mass at each corner - you need all the available tread on
the pavement to aid in braking force.
When going to a larger tire NEVER run them at the maximum pressure
indicated on the sidewall (unless you own a Hummer!). Larger tires are
designed for larger maximum load capacities - as the sidewall states.
This new maximum load capacity is achieved at that maximum air pressure.
Our Toyotas will never come close to this load capacity per tire! Thus,
the rule is - run the lowest pressure at which the entire tread is in
contact with the pavement. This will give you the best ride, longest
tire life, and added braking ability.
Now I'm running 33x12.50's on 8.5" wheels at 25psi. Previous I had two
sets of BFG AT's (32x11.50) on 8.5" wheels at 24-26psi (rotating them
side to side and front to back - X pattern, every 5K miles) and I got
70,000 miles from each set! (1990 4Runner).
Hope this helps! - Brian Rishaw
------------------------------
Date: Tue, 10 Mar 1998 22:23:11 -0700
From: Kevin Merrell
Subject: 32 X 11.50 on 7" Wheels
To: Toy4x4@tlca.org
I've read some of the suggestions given and need to put in my two cents.
Decreasing your tire pressure will help them wear more evenly, and it
will give you a smoother ride. But, this comes at a price.
A friend of mine worked as an Engineer at Michelin for about 8 years,
and he told me that the rolling resistance of the tires accounts for
approximately one-third of ALL frictional losses in the vehicle. The
more power losses you have in your vehicle, the worse your gas mileage
will get. Physics lesson - if there were no losses in your vehicle, it
would be a perpetual motion machine, once you started moving it would
never stop.
So, there's a tradeoff between the price of buying wider rims, and the
gas-guzzling price of running your tires at a low pressure (The
manufacturers recommended pressure minimizes rolling resistance). Or,
you can pressurize them all the way and pretend that they are Mickey
Thompson Baja Radials with tread on the sidewalls.
- -Kevin
- --
Kevin Merrell
merrellk@et.byu.edu
___
____| \__
| |
- --()-----()-
'85 Toyota SR5 Longbed, 130,000 miles
3" Rancho Lift with RS5000 shocks, Homemade bumpers
32x11.50 BFG Sport Kings
------------------------------
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