Should all 4 tires be inflated to the same pressure ?

Help !!

I own a 1994 Ford Probe GT. It came with 225/50/16 tires set for 44
psi.
I recently purchased 2 tires to replace the worn rear tires. These new
tires were Z-rated and called for 51 psi (I did not notice the
difference until later).

The question is : is such a difference between the front and rear tire
pressure harmful or dangerous ?

I have read that, for performance enhancements, some drivers will play
with the tire pressure and put more on the rear tires than on the
front. Supposedly, this helps them get the most of the car for their
peculiar circumstances.

But, how does that help the rest of us ? Should I exchange the rear
tires for similar tires as those in the front (i.e. similar tire
presssure)?

Any help is greatly appreciated.

Juan

Man oh man, I still find it hard to believe....

You need to read the sticker in the glove box or on the door post or in
the owners manual to find out the proper tire inflation!

That has absolutely nothing to do with the maximum allowed which is
printed on the side of the tire!!!!

My tires can take 50 psi. My 1/4 ton vehicle calls for 28 psi in them!

If I owned a 1 or 2 ton truck with a full load on it, then I 'could' put
the pressure up to 50 psi 'Maximun' to hold the load.

Tires fit more than one particular vehicle, eh.

Tires don't 'call for' any specific psi! They just can 'take' that many
if needed for the load rating of the vehicle involved.

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

Juan wrote:
>
> Help !!
>
> I own a 1994 Ford Probe GT. It came with 225/50/16 tires set for 44
> psi.
> I recently purchased 2 tires to replace the worn rear tires. These new
> tires were Z-rated and called for 51 psi (I did not notice the
> difference until later).
>
> The question is : is such a difference between the front and rear tire
> pressure harmful or dangerous ?
>
> I have read that, for performance enhancements, some drivers will play
> with the tire pressure and put more on the rear tires than on the
> front. Supposedly, this helps them get the most of the car for their
> peculiar circumstances.
>
> But, how does that help the rest of us ? Should I exchange the rear
> tires for similar tires as those in the front (i.e. similar tire
> presssure)?
>
> Any help is greatly appreciated.
>
> Juan

In your case, the rear tires should contain LESS air than the front.
Front wheel drive cars have the engine & drive train in the front &
practically no weight in the rear. I've always gone for tier WEAR &
experimented with pressure to that effect. Had an 86 Cutlass where I
found 32 in the front/ 24 in the rear was where they wore nice, 93
Cutlass supreme, 35 front/25 rear. Depends on the balance of your
particular vehicle. 97 Chevy PU 4x4, with C rated tires works well at
45 front/40 rear & I pump the rears to 50 when I'm using the bed. Good
luck.

(PA-ter) wrote in message . com>...
> In your case, the rear tires should contain LESS air than the front.
> Front wheel drive cars have the engine & drive train in the front &
> practically no weight in the rear. I've always gone for tier WEAR &
> experimented with pressure to that effect. Had an 86 Cutlass where I
> found 32 in the front/ 24 in the rear was where they wore nice, 93
> Cutlass supreme, 35 front/25 rear. Depends on the balance of your
> particular vehicle. 97 Chevy PU 4x4, with C rated tires works well at
> 45 front/40 rear & I pump the rears to 50 when I'm using the bed. Good
> luck.

Thanks.
The car handles really well with these 2 new rear tires. I am just
afraid that it may change the balance of the car and, at higher
speeds, may cause an accident.
I have read that the tire pressure suggested by the manufacturer is a
compromise reached to obtain the best handling and economy package for
the specific suspension of the car. Well, what is you change the tire
pressure so much that you affect that balance built into the car ? I
was just worried I had made a terrible mistake.

Juan

Juan wrote:
>
> (PA-ter) wrote in message . com>...
> > In your case, the rear tires should contain LESS air than the front.
> > Front wheel drive cars have the engine & drive train in the front &
> > practically no weight in the rear. I've always gone for tier WEAR &
> > experimented with pressure to that effect. Had an 86 Cutlass where I
> > found 32 in the front/ 24 in the rear was where they wore nice, 93
> > Cutlass supreme, 35 front/25 rear. Depends on the balance of your
> > particular vehicle. 97 Chevy PU 4x4, with C rated tires works well at
> > 45 front/40 rear & I pump the rears to 50 when I'm using the bed. Good
> > luck.
>
> Thanks.
> The car handles really well with these 2 new rear tires. I am just
> afraid that it may change the balance of the car and, at higher
> speeds, may cause an accident.

If you are running with the maximum allowed for the tire according to
the sidewall, you very well might cause an accident.

> I have read that the tire pressure suggested by the manufacturer is a
> compromise reached to obtain the best handling and economy package for
> the specific suspension of the car.

What manufacturer are you talking about? You need to go with the 'car'
manufacturers tire pressure, not the tire makers!

Well, what is you change the tire
> pressure so much that you affect that balance built into the car ? I
> was just worried I had made a terrible mistake.

Changing air pressure does radically affect the balance of the vehicle's
handling.

Even a 5 psi difference can make the difference of good safe driving and
being a road hazard.

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

>I have read that the tire pressure suggested by the manufacturer is a
> compromise reached to obtain the best handling and economy package for
> the specific suspension of the car. Well, what is you change the tire
> pressure so much that you affect that balance built into the car ? I
> was just worried I had made a terrible mistake.
>
> Juan

You bought a tire made by a manufacturer in your size, not made
explicitly for your car. The pressure indicated on the sidewall is the
MAXIMUM pressure this particular unit will tolerate safely. Whatever
size it is, it fits a myriad of vehicles with different drivetrain,
weight balance, brake bias & overall suspension differences, so your
not comprimising saftey in any way by suttle changes in tire pressure.
If you run extremely high or low pressure, yes this will cause a
problem. I'm thinking if you put that 51psi in the rear of a probe,
breaking the rear end loose under hard cornering will more likely
occur than if you ran, say, about 30 or 35. I'm not telling you to go
out & crash the thing trying to figure it all out, merely giving you
info to school you a little on pressure. Years ago the max pressure
ratings were increased on a particular brand we were selling from 35
to 41. The tire didn't change a lick, but the manufacturer had to
comply with new regulations handed down by Big Brother (who else) to
increase fuel mileage by creating less rolling resistance with the
higher pressure. Your tire may reflect the same, 51psi may be what the
government told them to put on there, not necessarily what it's
optimum pressure will be on your car.Good luck.

Mike Romain > wrote in message >...

> If you are running with the maximum allowed for the tire according to
> the sidewall, you very well might cause an accident.

Well, this is quite embarassing.
I just looked at the door panel sticker :
The front tires are set to 32 psi and the rear at 26 psi.
I am almost twice as high as it should be !!

> What manufacturer are you talking about? You need to go with the 'car'
> manufacturers tire pressure, not the tire makers!

Well, the tires, front and rear, were installed, by the shop, at the
setting on the tire itself. I just kept doing it myself at the same
setting. Once I bought these rear tires, I noticed the 7 psi
difference and that is what got me thinking.

Thanks for the advice.

Juan

Juan wrote:
>
> Mike Romain > wrote in message >...
>
> > If you are running with the maximum allowed for the tire according to
> > the sidewall, you very well might cause an accident.
>
> Well, this is quite embarassing.
> I just looked at the door panel sticker :
> The front tires are set to 32 psi and the rear at 26 psi.
> I am almost twice as high as it should be !!
>
> > What manufacturer are you talking about? You need to go with the 'car'
> > manufacturers tire pressure, not the tire makers!
>
> Well, the tires, front and rear, were installed, by the shop, at the
> setting on the tire itself. I just kept doing it myself at the same
> setting. Once I bought these rear tires, I noticed the 7 psi
> difference and that is what got me thinking.
>
> Thanks for the advice.
>

You are welcome.

It is really too bad that the tire shops are too freaking lazy to
properly set the tires.

They blow them up to the max allowed to seat the beads nice and tight,
then they are 'supposed' to drop them down to what the vehicle calls
for!

I will bet that the same shop just used an impact gun and drove the
wheel lugs on at full power too!

When they do this it causes warped rotors. The new composite rotors on
most vehicles require that the wheel lug nuts get hand torqued on or you
will end up with a pulsing brake pedal.

And maybe a wheel that you can't get the lugs off by hand if you have a
flat because they are on too tight...

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