Hi All. It's cold up here in the Northeast section of the United Since, and it figures that on the first day of winter I am getting low tire pressure warnings--see image below. I know tire pressures will drop when the ambient temperature is cold, but does anyone have any recommendations on what tire pressures to keep them at when it's cold outside? Should I keep the the PSI 2 or 3 levels below the recommended pressures--knowing that when the temperatures / tires warm up, the pressure can increase by up to 4-6 PSI? And it is best to add air before the vehicle is driven (before tires have a chance to heat up)? I appreciate any recommendations, and not sure if this topic has been covered before. Thanks for the advice.
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Current:
2020 Discovery HSE Luxury Si6 Fuji White
Former:
2015 RRS Autobiography Fuji White
2011 RRS Supercharged Fuji White
2008 LR2 Fuji White

 

Lookup light load pressure setting. If you carry 4 passengers or so you can use that setting.

I have never changed the pressure setting based on ambient temps, as the tires will still be colder when you drive compared to a hot 100F day.

 

Agree with andries...I always use the light load settings found in your menu on the gauges panel. I leave 34 in all of them. Rides nice and still handles great.

 

I prefer 36-38 front and 38-40 rear with the light load setting. I only bump it up to normal load pressures when we carry 6/7 or load it up with 4 and lots of luggage/dog, etc. I found the ride much nicer with the lighter load pressures on a daily basis, as it normally has 1-4 people in it.

 

Tyres are supposed to be filled when cold. That’s what the ratings refer to. They have already taken into account that their pressure will increase slightly when driven.
I agree with the previous commenters, use the light load warning setting and put a few PSU over that. Typically I add 4psi.
Too much and the ride gets harsher (as the rude absorbs a lot of bumps) and you may het higher wear in the center of the tyre although you would get slightly improved fuel economy. On a cost and comfort basis I prefer the lower pressure.
Interestingly the wife’s new Kia threw the warning due to reporting 26psi in each tyre when the temps dropped below freezing, having bought the car in a hot 40degC July with 40psi in the tyres at the time. We bought the Land Rover the same week which came with Good Year tyres filled with Nitrogen and it reports is still has 36 front and 40 rear so only the front has dropped slightly. They were both supposedly filled with nitrogen and both have 1800 miles now. I wonder if the Kia dropping more is because they didn’t actually fill it with Nitrogen, it has a cheap brand of tyre, or that they are simply smaller tyres...

 

Since it is Boyle's Law working: what is the tire pressure once you have driven ten miles or so. If it warms up to normal, might want to leave it alone for ride quality issues noted above.

On my current car, I try to run 35 front, 36 rear once warmed up giving -- to my feel -- best ride and handling balance for the Michelins. Book calls for 33 all around. In the cold, 30* or so, it drops to 31, in the summer, maybe 36* when 'cold.' So I add some air at first frost, and dump some first day over 80*

 

Light load and also get nitrogen put in tires. Nitrogen stays constant regardless of temp.

 

Sorry but that's a myth.
Nitrogen is supposed to be slower at leaking through the pores of the rubber so it might be less likely to lose pressure over time, but that's negligible.
It still expands and contracts with temperature. PV=nRT. Can't change the laws of physics. As T (temperature) decreases, either P (pressure) or V(volume) must decrease regardless of the gas involved. Since Volume is constant, then Pressure must decrease.
Also, what you get when you pay for nitrogen is a little bit of nitrogen: Air is already 78 percent nitrogen so maybe you'd get 22 percent. But that's only if you removed all the air from the tire before filling with nitrogen and I doubt tire stores are doing that. And, if you ever top up your tires in the future, you have to do it with nitrogen otherwise you end up with less and less proportion of nitrogen.

You'd be better off to spend your money on a tire gauge and maybe a small compressor and check or top off your tires monthly. Especially in the fall as temperatures drop. In the spring and summer you might be able to just let a little air out each month.

 

Thanks, shocking the folks who missed seventh grade science.

 

Just a note, the D5 actually changes the recommended tire pressure as you drive and increase it by a few PSI. Not sure if it has a temp sensor in the tires or just does a swag based on how far/fast you have driven and ambient temps.

I have not noticed it changing the recommended temps when the ambient temps change. I have always used the same cold pressure setting irrespective of ambient temp, my reasoning being that if ambient temps drop significantly the tire operating temperature also drop similarly.

What I have observed is a nice change in pressure if you have a significant change in elevation from say sea level to 10k ft. I always keep that in mind if I air down/up in the mountains.