proper tire inflation?

well i finally got the Michelin Cross Terrain 255/60/17 to replace the stock
Michelin LTX M/S 245/65/17 ... first impression is: they are great!

i feel like i got a pretty good deal on them at Tire Rack ($120 delivered)
and the dealer did the mount and install for $54.16 for all 4 tires ... i
could not believe that the dealer actually had the best deal on install ...

on the way home i checked the tire pressure and it ranged in the upper 30's
PSI in all 4 tires (not cold) ... has the dealer over-inflated the tires?

what is a good way of figuring out the approproriate inflation pressure for
this size tire on an infiniti QX4?

4000 psi wrote:
>
> well i finally got the Michelin Cross Terrain 255/60/17 to replace the stock
> Michelin LTX M/S 245/65/17 ... first impression is: they are great!
>
> i feel like i got a pretty good deal on them at Tire Rack ($120 delivered)
> and the dealer did the mount and install for $54.16 for all 4 tires ... i
> could not believe that the dealer actually had the best deal on install ...
>
> on the way home i checked the tire pressure and it ranged in the upper 30's
> PSI in all 4 tires (not cold) ... has the dealer over-inflated the tires?
>
> what is a good way of figuring out the approproriate inflation pressure for
> this size tire on an infiniti QX4?

You are not all that different a size tire than stock, so the factory pressures listed in the Owner's Manual would be a good place to start. Here are some ideas you might try if you want to experiment a little from there:
http://www.4crawler.com/Diesel/Tires.shtml#ProperInflation

--
Roger

i did the math according to this link and the pressure comes out to be about
20 psi for the load that i have ... can i seriously run the pressure that
low?

"Roger Brown" <[email protected]> wrote in message
news:[email protected]...
> 4000 psi wrote:
> >
> > well i finally got the Michelin Cross Terrain 255/60/17 to replace the
stock
> > Michelin LTX M/S 245/65/17 ... first impression is: they are great!
> >
> > i feel like i got a pretty good deal on them at Tire Rack ($120
delivered)
> > and the dealer did the mount and install for $54.16 for all 4 tires ...
i
> > could not believe that the dealer actually had the best deal on install
....
> >
> > on the way home i checked the tire pressure and it ranged in the upper
30's
> > PSI in all 4 tires (not cold) ... has the dealer over-inflated the
tires?
> >
> > what is a good way of figuring out the approproriate inflation pressure
for
> > this size tire on an infiniti QX4?
>
> You are not all that different a size tire than stock, so the factory
pressures listed in the Owner's Manual would be a good place to start. Here
are some ideas you might try if you want to experiment a little from there:
> http://www.4crawler.com/Diesel/Tires.shtml#ProperInflation
>
> --
> Roger

4000 psi wrote:
>
> i did the math according to this link and the pressure comes out to be about
> 20 psi for the load that i have ... can i seriously run the pressure that
> low?

You'll likely not come up with one answer or one pressure. I've run 20-22 psi in my 33x10.50 BFGs on the highway and they do OK, no signs of overheating. But for extended high speed driving, I generally run about 30 psi or higher. Start out with the
suggested inflation specs for the vehilce, often in an Owner's manual, sticker on the door jamb or glove box, etc. If that feels too soft, increase the pressure, if too firm, decrease it. Watch the tread wear and tread contact patch and come up with
something that works for you, your driving style, your vehicle and tires.

--
Roger

"4000 psi" <nospam@for_me.com> wrote in message
news:FXmNb.4176$Xq2.206@fed1read07...
: well i finally got the Michelin Cross Terrain 255/60/17 to replace the
stock
: Michelin LTX M/S 245/65/17 ... first impression is: they are great!
:
: i feel like i got a pretty good deal on them at Tire Rack ($120
delivered)
: and the dealer did the mount and install for $54.16 for all 4 tires ... i
: could not believe that the dealer actually had the best deal on install
....
:
: on the way home i checked the tire pressure and it ranged in the upper
30's
: PSI in all 4 tires (not cold) ... has the dealer over-inflated the tires?
:
: what is a good way of figuring out the approproriate inflation pressure
for
: this size tire on an infiniti QX4?


Tire dealers routinely pay absolutely no attention to tire pressure. I have
seen them with 35 pounds or 20 pounds in tires on the same truck. Strike a
chalk mark across the tread and roll the vehicle a few feet. Observe the
wear pattern on the chalk mark. Inflate or deflate accordingly.

"Roger Brown" <[email protected]> wrote in message
news:[email protected]...
> 4000 psi wrote:
> >
> > i did the math according to this link and the pressure comes out to be
about
> > 20 psi for the load that i have ... can i seriously run the pressure
that
> > low?
>
> You'll likely not come up with one answer or one pressure. I've run 20-22
psi in my 33x10.50 BFGs on the highway and they do OK, no signs of
overheating. But for extended high speed driving, I generally run about 30
psi or higher. Start out with the
> suggested inflation specs for the vehilce, often in an Owner's manual,
sticker on the door jamb or glove box, etc. If that feels too soft,
increase the pressure, if too firm, decrease it. Watch the tread wear and
tread contact patch and come up with
> something that works for you, your driving style, your vehicle and tires.
>
> --
> Roger

"Roger Brown" <[email protected]> wrote in message
news:[email protected]...
> 4000 psi wrote:
> >
> > i did the math according to this link and the pressure comes out to be
about
> > 20 psi for the load that i have ... can i seriously run the pressure
that
> > low?
>
> You'll likely not come up with one answer or one pressure. I've run 20-22
psi in my 33x10.50 BFGs on the highway and they do OK, no signs of
overheating. But for extended high speed driving, I generally run about 30
psi or higher. Start out with the
> suggested inflation specs for the vehilce, often in an Owner's manual,
sticker on the door jamb or glove box, etc. If that feels too soft,
increase the pressure, if too firm, decrease it. Watch the tread wear and
tread contact patch and come up with
> something that works for you, your driving style, your vehicle and tires.
>
> --
> Roger

offroad on sand and mud you can go down to 8 PSI on Troopers (31x10.5 R15)
for a period.

i contacted Tire Rack where i bought the tires and they recommended 32-35
psi, the glove box sticker suggests 26 psi front and rear ... what a
discrepancy

"rnf2" <[email protected]> wrote in message
news:[email protected]...
>
> "Roger Brown" <[email protected]> wrote in message
> news:[email protected]...
> > 4000 psi wrote:
> > >
> > > i did the math according to this link and the pressure comes out to be
> about
> > > 20 psi for the load that i have ... can i seriously run the pressure
> that
> > > low?
> >
> > You'll likely not come up with one answer or one pressure. I've run
20-22
> psi in my 33x10.50 BFGs on the highway and they do OK, no signs of
> overheating. But for extended high speed driving, I generally run about
30
> psi or higher. Start out with the
> > suggested inflation specs for the vehilce, often in an Owner's manual,
> sticker on the door jamb or glove box, etc. If that feels too soft,
> increase the pressure, if too firm, decrease it. Watch the tread wear and
> tread contact patch and come up with
> > something that works for you, your driving style, your vehicle and
tires.
> >
> > --
> > Roger
>
>

26 psi????

What are you driving one of those fords that put too low a pressure
sticker on them so the tires explode and flip the vehicles?

There is a recall for that sticker if that is the case.

That does seem low though. That said, I run 28 psi in my Jeep CJ7 with
33" tires and 32 psi in my Cherokee with p235x15 tires.

I check mine using the 'chalk method'. I set the psi then run some
chalk across the tread and drive in a straight line. I then see how
much chalk is worn away.

At 28 psi, I have about 1/4" of chalk left on the outside edges of the
tread. When the tire shop installed my tires and put 36 in them I only
wore out 3" of the center of the tread. Not a nice 'footprint'.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

4000 psi wrote:
>
> i contacted Tire Rack where i bought the tires and they recommended 32-35
> psi, the glove box sticker suggests 26 psi front and rear ... what a
> discrepancy
>
> "rnf2" <[email protected]> wrote in message
> news:[email protected]...
> >
> > "Roger Brown" <[email protected]> wrote in message
> > news:[email protected]...
> > > 4000 psi wrote:
> > > >
> > > > i did the math according to this link and the pressure comes out to be
> > about
> > > > 20 psi for the load that i have ... can i seriously run the pressure
> > that
> > > > low?
> > >
> > > You'll likely not come up with one answer or one pressure. I've run
> 20-22
> > psi in my 33x10.50 BFGs on the highway and they do OK, no signs of
> > overheating. But for extended high speed driving, I generally run about
> 30
> > psi or higher. Start out with the
> > > suggested inflation specs for the vehilce, often in an Owner's manual,
> > sticker on the door jamb or glove box, etc. If that feels too soft,
> > increase the pressure, if too firm, decrease it. Watch the tread wear and
> > tread contact patch and come up with
> > > something that works for you, your driving style, your vehicle and
> tires.
> > >
> > > --
> > > Roger
> >
> >

its an Infiniti QX4 2001 ... when you use the chalk method ... do you run
the chalk right across the entire width of the tire? then when you roll the
car forward do you examine the chalk foot print on the ground or on the
tire?

"Mike Romain" <[email protected]> wrote in message
news:[email protected]...
> 26 psi????
>
> What are you driving one of those fords that put too low a pressure
> sticker on them so the tires explode and flip the vehicles?
>
> There is a recall for that sticker if that is the case.
>
> That does seem low though. That said, I run 28 psi in my Jeep CJ7 with
> 33" tires and 32 psi in my Cherokee with p235x15 tires.
>
> I check mine using the 'chalk method'. I set the psi then run some
> chalk across the tread and drive in a straight line. I then see how
> much chalk is worn away.
>
> At 28 psi, I have about 1/4" of chalk left on the outside edges of the
> tread. When the tire shop installed my tires and put 36 in them I only
> wore out 3" of the center of the tread. Not a nice 'footprint'.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> 4000 psi wrote:
> >
> > i contacted Tire Rack where i bought the tires and they recommended
32-35
> > psi, the glove box sticker suggests 26 psi front and rear ... what a
> > discrepancy
> >
> > "rnf2" <[email protected]> wrote in message
> > news:[email protected]...
> > >
> > > "Roger Brown" <[email protected]> wrote in message
> > > news:[email protected]...
> > > > 4000 psi wrote:
> > > > >
> > > > > i did the math according to this link and the pressure comes out
to be
> > > about
> > > > > 20 psi for the load that i have ... can i seriously run the
pressure
> > > that
> > > > > low?
> > > >
> > > > You'll likely not come up with one answer or one pressure. I've run
> > 20-22
> > > psi in my 33x10.50 BFGs on the highway and they do OK, no signs of
> > > overheating. But for extended high speed driving, I generally run
about
> > 30
> > > psi or higher. Start out with the
> > > > suggested inflation specs for the vehilce, often in an Owner's
manual,
> > > sticker on the door jamb or glove box, etc. If that feels too soft,
> > > increase the pressure, if too firm, decrease it. Watch the tread wear
and
> > > tread contact patch and come up with
> > > > something that works for you, your driving style, your vehicle and
> > tires.
> > > >
> > > > --
> > > > Roger
> > >
> > >

The new tires are not far from stock. Start at the recommended 26
f/r, then go up 2lbs all around to see if that helps or hurts, etc.
Don't listen to Tire Rack, they did not engineer the vehicle.

"4000 psi" <nospam@for_me.com> wrote in message
news:CmTNb.11442$Xq2.5047@fed1read07
> i contacted Tire Rack where i bought the tires and they recommended
> 32-35 psi, the glove box sticker suggests 26 psi front and rear ...
> what a discrepancy