How many miles/minutes of driving are needed before a tire is no longer considered to be at "cold" temperature. I feel like this is never actually discussed when you buy a new set of tires with respect to longevity. Also if you are just idling down the road, does a tire ever really reach a "normal operating" pressure? How about ambient temperature? Seems like the tire industry deliberately leave this undefined to further their own interests....
"Cold" tire pressure.
- Thread starter Jarpin
- Start date
This is why you are instructed to take the pressures cold, hours after driving. The longer you wait the more likely the pressure has settled out. I would assume if you've driven at all right before taking the pressure it's no longer a "cold reading".
Well never pass up the opportunity to ascribe some truly random variable to a conspiracy theory, but one of my owner’s manuals says the pressure should be checked before the vehicle is driven one mile.
Too many factors to consider. When you can point an infrared thermometer at the tire and it is no longer the same temperature as when you started, its no longer cold.
What is the tire itself, high performance sticky or highway tire? The vehicle weight? Cargo? Asphalt or concrete? Additional cargo? Ambient temperature? Day or night?
What is the tire itself, high performance sticky or highway tire? The vehicle weight? Cargo? Asphalt or concrete? Additional cargo? Ambient temperature? Day or night?
I've had that happen, especially here in FL.
Good point...
Well, it's about a balmy 48 degrees here...I've got Nitrogen filled all season touring tires. I idled down the road (100% no throttle) at about 15-20 mph and around the corner all the way to the next street over, then drove about 35 mph for about 1,000 feet straight into the Costco where I topped it off with nitrogen to 33psi, (Just one psi above "cold") before driving to the Big O tires for the first rotate and balance. Total distance to the Costco from my house was 0.8 miles. Sound about right?
a mile
I just use my portable pump in my driveway on a weekend morning, before I drive anywhere. That pump uses the ambient air around me, so it's 78% nitrogen. And it's free. 
Nitrogen LOL. Just fill it up with air at home.
@CapriRacer will know the answer
Also speed is a factor 1 mile at a crawl or 1 mile at 60 will give different result.
Here I'm going on memory, they recommend to check it in the morning before driving.
Operating temp is reached after driving for 15 or so mile at 60.
Having a TPMS that gives a read out for each tire really opened my eyes to how much the pressure changes from cold to hot. Just driving a mile to the filling station in the morning with the sun shinning on one side will raise the pressure of those tires a couple of degrees.
You can turn this around and say if the pressure rises from cold to hot by much more than 10% then the cold pressure was too low. For my car running 32 psi cold that means a 3.2 psi rise which equates to approx 18 Deg C rise in temperature.
I often watch my tire pressures while driving. On a warm day my pressures can rise by as much as 3 psi in 10 miles of driving from friction alone. I have also observed up to plus 3 psi change due to air temperature alone without driving. The effects are cumulative, so a pressure at 50°F in the morning without driving can rise by as much as 6 psi after 10 miles of driving at 80°F in the afternoon. There are many variables at play, including tire design, tire pressure, air temperature, road temperature, road condition, sunshine, etc., but mine do not exceed +3 psi from friction alone on a hot sunny day on blacktop roads. YMMV
Sorry, what's the correlation ?