Freezing is not even necessary.  Any water present wil contribute its
 vapor pressure to the pressure in the tire.  The vapor pressure of water
increases with temperature more rapidly than the pressure of a dry gas
changes with temperature.

On Tue, Oct 20, 2015 at 1:16 PM, Jon VO <jondvo@gmail.com> wrote:

> The reason Nitrogen is used is because it eliminates water vapor issues
> with freezing. Nitrogen is free of water vapor and "dry" air is as
> expensive to generate.
>
>
> On 10/20/2015 9:55 AM, Angus Gordon wrote:
>
>> PV = nRT ( T in Kelvin)
>>> It's all you need to know Angus. For tires, balloons, business meetings
>>> :)
>>>
>>> I knew I'd been missing something. It's all about hot air, says
>> Alistair...
>>
>> Angus
>>
>>
>>
>>> On Oct 19, 2015, at 3:53 PM, Angus Gordon <birdworks@GMAIL.COM> wrote:
>>>>
>>>> Thanks David, I've been using a rule of thumb of 1% per 5F for a long
>>>> time but I don't know where it came from. Michelin perhaps. Normally I only
>>>> use it to overinflate when headed to a cold destination. Kept me out of the
>>>> weeds so far...
>>>>
>>>> Angus
>>>>
>>>>
>>>> On Oct 19, 2015, at 3:46 PM, David Beierl <dbeierl@attglobal.net>
>>>>> wrote:
>>>>>
>>>>> At 11:19 PM 10/17/2015, Angus Gordon wrote:
>>>>>
>>>>>> I have experience with nitrogen filled tires on aircraft and can tell
>>>>>> you that it certainly doesn't negate pressure changes with temperature.
>>>>>> That's still something we deal with. I don't see any real value in using
>>>>>> nitrogen in car tires.
>>>>>>
>>>>> I believe pressure change as a percentage per degree will be
>>>>> essentially the same no matter what gas or combination of gases is used to
>>>>> fill a tire.  It amounts to roughly one psi per ten degrees Fahrenheit for
>>>>> tires at ordinary pressures and temperatures.
>>>>>
>>>>> Yrs,
>>>>> d
>>>>>
>>>>