Tire pressure adjustments for outside temps.

[Firn]

From Ford. I believe this from an older truck, maybe 2008, but the current trucks should be the same.

Sponsored

 

[Hammick]

I don't understand the garage temp of 70 degrees. How do I use this chart if my garage temperature if 50 degrees or lower?

 

[rraustad]

I don't understand the garage temp of 70 degrees. How do I use this chart if my garage temperature if 50 degrees or lower?

My interpretation. Using a garage temp of 70 F and a placard pressure of 35 psi, if outdoor temp is 50 F and you fill the tires to 37 psi then when you move the truck outdoors the tire pressure will be 35 psi. At a garage temp of 50 F you would expect the tire pressure in the garage to be 35 psi and if 30 F outside then you would fill the tires to 37 psi (2 psi difference between 50 and 30 outdoor temp) so when the truck is outdoors the tire pressure would be 35 psi.

 

[jetfixr1]

Meh. Too complicated. 41 cold, 45 hot. Give or take 1 PSI.

 

[RickLightning]

My garage is within 10 degrees of outside when it is cold. I simply fill tires to proper PSI once a month. It is not sitting at 20 degrees when you are driving. On most trips, 42 cold is 49 or 50 driving.

 

[SSNutz]

Does anyone run the psi on the higher side for better range and wear?

 

[P-38]

Really adding 10psi does not change range/efficiency? I noticed the difference on my ICE vehicles... Maybe it's the brick like aero of a truck vs. mid size that makes the tires not as critical.

Are you normally running 70mph? My thinking is tire pressure might matter more if most miles are below 55-60 where air resistance is not as large of a component of the losses.

I love the data on setting psi in garage vs outdoor temp.

 

[Ricks Lightning]

This reminds me of a Seinfeld episode

https://images.app.goo.gl/JSRbz8cURTWg8XBAA
Rick

 

[xwing]

Does anyone run the psi on the higher side for better range and wear?

Yes, I run 44-45lbs cold year round.

 

[RickLightning]

When purposely running mine 4psi low, so 32 psi on a recomended 36, it only gained 3psi over an hour long drive at 20f. The rise in temp was less when starting psi was higher.

.

For those interested, what this is saying is that for any given load capacity you need to raise tire pressure for cold outside temps.

For the starting temp I believe you can convert this into delta temps instead of absolute. Don't think of it as starting at 70 and then going to 20f. Think of it as 50 degree difference..
If you were setting pressure at 50f, and driving at 10f, that is a 30 degree diff, then use the chart like it is 70f to 40f, a 30 degree difference.

50 - 10 is a 40 degree difference.

 

[Runaway Tractor]

Wow how did I ever manage that tire pressure in all my vehicles the last 25yrs without this!?!?

Seriously? Do people really need a cross reference table to put air in their tires??

 

[1Jetpilot]

Why don't someone just tell us how to use the chart if the placarded tire PSI is 38 and your garage temp is 20? I get 40 PSI

 

[Runaway Tractor]

I have an amazing idea that might be simpler than referring to a chart and doing math. Ready for it?
.
.
.
.
Put air in the tire if it's low.

 

[inchman254]

I use 1 PSI per 10F difference between garage and outside. The actual temp of your garage doesn't matter... Only the difference.

"Cold" tire pressure means in the driving environment.

 

[RickLightning]

Unless you heat or cool your garage, this is totally unnecessary. Let's say that I check my tires at 8AM. Garage is 30 degrees. Outside is 20 degrees. I do the math, and fill my tires.

Now, I go for a drive at 2PM. Temp has risen to 50 degrees! Crap, I pull back in the garage and lower my tire pressure....

I do my tires on the first Saturday of each month. In the garage, without the sun hitting them. The only adjustment I make is going a pound or two higher as winter enters, and a pound or so lower as Spring comes.

With the inaccuracy of tire gauges, the reality is that you are plus or minus 2 to 4 pounds anyway.

Sponsored