17" wheels tire pressure?

[z6cyl]

My dealer failed to adjust the tire pressure on delivery of my new Mustang. The door sill states 32psi recommended for my tires/wheels, so I adjusted the tires down from 45psi to 32psi.

After a bit of settling it seems like they are now at 31psi on 3 corners and 32psi on the last corner. Should I try to get them back up to the 32psi on the 3 corners or call it good?

Also what will happen to the tire pressure in the winter? Right now its summer in CO, and I adjusted the tires while they were "cold" probably room temperature or slightly warmer in the garage. In the winter it will be below freezing. Will I need to add some air to the tires as it gets colder (but before winter tires) or will the psi change not be that great?

These are epic noob questions but I've never cared about a car this much so I want to make sure its done right.

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[DickR]

Yes you should increase the cold tire pressures to 32 psi. Assuming the tires won't be cold when you add air simply add a couple of pounds over whatever the pressure is when you add air. Then lower to 32 the next morning before the sun heats the tires or you drive the car.

The owner manual describes the affects of temperature on tire pressure. Page 258.

Basically add or remove air to cold tires to adjust for seasonal ambient temperature changes.

How Temperature Affects Your Tire
Pressure
The tire pressure monitoring system
monitors tire pressure in each pneumatic
tire. While driving in a normal manner, a
typical passenger tire inflation pressure
may increase about 2 to 4 psi (14 to 28
kPa) from a cold start situation. If the
vehicle is stationary overnight with the
outside temperature significantly lower
than the daytime temperature, the tire
pressure may decrease about 3 psi (21
kPa) for a drop of 30°F (17°C) in ambient
temperature. This lower pressure value
may be detected by the tire pressure
monitoring system as being significantly
lower than the recommended inflation
pressure and activate the system warning
light for low tire pressure. If the low tire
pressure warning light is on, visually check
each tire to verify that no tire is flat. If one
or more tires are flat, repair as necessary.
Check the air pressure in the road tires. If
any tire is under-inflated, carefully drive
the vehicle to the nearest location where
air can be added to the tires. Inflate all the
tires to the recommended inflation
pressure.

 

[hiccup]

My dealer failed to adjust the tire pressure on delivery of my new Mustang. The door sill states 32psi recommended for my tires/wheels, so I adjusted the tires down from 45psi to 32psi.

After a bit of settling it seems like they are now at 31psi on 3 corners and 32psi on the last corner. Should I try to get them back up to the 32psi on the 3 corners or call it good?

Also what will happen to the tire pressure in the winter? Right now its summer in CO, and I adjusted the tires while they were "cold" probably room temperature or slightly warmer in the garage. In the winter it will be below freezing. Will I need to add some air to the tires as it gets colder (but before winter tires) or will the psi change not be that great?

These are epic noob questions but I've never cared about a car this much so I want to make sure its done right.

After a month of ownership I just thought of checking mine:doh: ..so I had 46-47 lbs. in each tire ..I lowered it 5 lbs in each tire. Must be some assembly line reason for that:shrug: I bet I let good pure nitrogen out to atmosphere too

 

[DickR]

After a month of ownership I just thought of checking mine:doh: ..so I had 46-47 lbs. in each tire ..I lowered it 5 lbs in each tire. Must be some assembly line reason for that:shrug: I bet I let good pure nitrogen out to atmosphere too

Did you ever check the pressures using gauge mode on the instrument panel display? It can serve as a verification that your gauge is relatively accurate since the values should be within 1 or 2 lbs of each other (gauge versus instrument panel reading)

Any particular reason why you didn't lower the pressures to the specs?

 

[hiccup]

Did you ever check the pressures using gauge mode on the instrument panel display? It can serve as a verification that your gauge is relatively accurate since the values should be within 1 or 2 lbs of each other (gauge versus instrument panel reading)

Any particular reason why you didn't lower the pressures to the specs?

I didnt trust my gauge totally.. Huh, didn't know about gauge mode..I will be rereading my manual now:headbonk:

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