pinky said:
This can be a technically deep subject with many what if's...
or...
You can break it down to it's basics...
Regarding the OEM recommended tire pressure sticker...
it applies to the OEM tires ONLY as stated in the 1st paragraph of the quote
from the owner manual...
A vehicle-specific Tire and
Loading Information label is
attached to the vehicle. This
label shows the vehicle's original
equipment tires and the correct
inflation pressures for the tires
when they are cold.
The
recommended cold tire inflation
pressure, shown on the label, is
the minimum amount of air
pressure needed to support the
vehicle's maximum load carrying
capacity.
For additional information
regarding how much weight
the vehicle can carry, and an
example of the Tire and Loading
Information label, see Vehicle
Load Limits.
How you load the vehicle affects
vehicle handling and ride
comfort. Never load the vehicle
with more weight than it was
designed to carry[/color]
Once you change brand and/or size of tires the recommendations of the Tire Manufacturer take precedence.
You should check the website of the Tire Manufacturer for specifics
The tires sidewall contains a "Maximum PSI for Maximum Load" rating.
This information is usefull when you plan to load the vehicle to it's maximum weight.
The tires PSI should be set accordingly.
One can also benefit from this information as far as gas milage is concerned.
Overinflation (even when PSI is lower than the tires maximum PSI) is not a good idea because it may cause the tire to wear more quickly in the center tread area.
But generally higher PSI will improve milage.
The following example may not apply to you since you have changed brands.
But with the OEM Michelin tires on OUR Equinox...the "door sticker" says 35.
For better MPG (lower rolling resistance) I run them at 40 which is still below the maximum PSI noted on the tire.
Assuming you bought the 255/60/17 Bridgestone Dueler H/L Alenza's
The Tire Rack website shows a maximum PSI of 44 PSI for Max Load conditions.
I would use that number as a starting point for where to run PSI to:
A. Maximize comfort while driving (the higher the PSI the firmer the ride) lower is better
b. Maximize MPG (the lower the PSI the more rolling resistance) higher is better
I would not run less than 35 all the way around
I would not run more than 40 all the way around (except in Max Load conditions)
IMHO...that 5 PSI is your "playground"