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weather question (Doc need not reply ;) )

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JPSmit

JPSmit

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A question for my fellow northern winter dwellers. It has been a little on the chilly side the last few days ( currently -14C/ 7 F ). when I get in the car my tire pressure monitor says I have low tire pressure. This of course because the cold contracts the air in the tires lowering the air pressure. After things warm up for a while it returns to normal. So, do I just leave it knowing that the pressure really isn't low and that it will get warmer - or do I top up the tires to cancel the warning knowing that as the weather warms up the tires will be a little overinflated.

thoughts?
 
Put warm air in the tires. Sheesh :rolleyes:
 
Take a look at this chart on page 3:


You can figure what the proper psi should be at a given temp. As psi will increase while driving, I'd assume (always dangerous!) that a psi five to 10 pounds over the recommended psi won't cause a problem.

"Your mileage may vary!"

(And yes, I do "overinflate" when winter really hits. Today's high will be around 10F.)
 
When you say “warm up after a while” I assume you mean while driving on the same day that the monitor registered low pressure when sitting idle. Recommended tire pressures assume that you are filling the tires with ambient air and that pressure will increase during driving (typically a couple psi). Personally I adjust the tire pressure to be the recommended pressure at ambient temperature all season long. That’s for optimum balance of handling, comfort and tire wear...if one drives very little in the winter though, I wouldn’t worry about it too much except for extremes (like the last time you filled it was 95 deg in August and now it’s 5 deg in January and the delta is 5 psi (including a little leakage) for TR3 front tires that are normally 24 psi).
 
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leave them softer in the winter,
under pressure gives more grip, over pressure gives better fuel economy.
 
Supposed to check pressures cold and inflate to proper pressure. When it weather warms up, check again.
 
JPSmit said:
A question for my fellow northern winter dwellers. It has been a little on the chilly side the last few days ( currently -14C/ 7 F ). when I get in the car my tire pressure monitor says I have low tire pressure. This of course because the cold contracts the air in the tires lowering the air pressure. After things warm up for a while it returns to normal. So, do I just leave it knowing that the pressure really isn't low and that it will get warmer - or do I top up the tires to cancel the warning knowing that as the weather warms up the tires will be a little overinflated.

thoughts?
Click to expand...
Good question. My current car has very "precise" tire pressure sensors, and report exact PSI (I have checked they are accurate) and tire temperature. It "complains" when the temperature goes down a bit - but usually in the afternoon when it is a bit warmer, everything is back at the correct pressure. - I would ignore that tiny pressure shift. Up in the great white north it is cold in the morning, cold in the afternoon and cold at night (I don't miss that cold!). I would inflate to the correct pressure in the morning when winter begins and if it is really cold for a few days add more air as needed.
 
During winter I check pressures weekly. Up and down cold and warm spells require a little more maintenance. I have 42 tires, but only check the 13 on our main drivers.
 
If the tires in the cold are showing below the minimum pressure, I would add just enough below a mean pressure, staying below the maximum range. That way, you should be fine when the tires warm and when they’re still cold.
 
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