Tire pressure should be 3-5 psi higher during winter time

[bubbleguy]

I recently have my 2011 Pilot checked and the technician suggested 3-5 psi higher for tire pressure during winter time (I live in North Dakota). I'm not using winter tires; the tires were original ones with a recommended pressure of 32 psi. The pressure now is 35 PSI.

Does this make sense?

[humanoid]

Yes, air condenses when the air is cold and expands when air is hot. Raising your PSI won't make your Pilot explode, relax, it's fine.

[xGS]

Originally Posted by bubbleguy

I recently have my 2011 Pilot checked and the technician suggested 3-5 psi higher for tire pressure during winter time (I live in North Dakota). I'm not using winter tires; the tires were original ones with a recommended pressure of 32 psi. The pressure now is 35 PSI.

Does this make sense?

It makes some sense depending upon where the car is parked overnight.

If you park in an attached and/or heated garage, the tires won't get as cold (and thus have a higher "cold" pressure) than they would if you checked them after parking outside. The 3-5psi boost in pressure during the winter is intended to compensate for this effect.

Read more about it here: Winter Tech - Higher Tire Pressures for Winter Driving

[rocky]

I always start winter with 2-4 psi more than normal to account t for the Loss of tire pressure caused by lower temps.

[refotsirk]

I do recall hearing that for every 10 degrees temperature drop, you will lose 1 (one) p.s.i. in pressure.
So, over two weeks of fluctuating winter temps, it isn't unusual to have a substantial loss. I have seen this happen.
On the flip side....I have noticed in a quick spring season warm up, I check my tire pressures and it is as though I have over inflated my tires with the ambient air temp expanding my p.s.i pressures. (having filled my tire to 35 psi on a 21 degree day, and a few days later it is 74 degrees) Big climb of about 4-5 psi or more.
I have always been curious on how filling nitrogen into the tire will work or not work over the course of a winter. Airplanes use this gas in the tires.
Good to be vigil on the tires.

[rocky]

75% of the sir we breath is Nitrogen.

[refotsirk]

Good point,(as Air is 78 percent nitrogen, just under 21 percent oxygen and some odd co2), but I was just mentioning the use of 100% nitrogen as it is harder to "slow leak" compared to regular air and perhaps no water being injected into the tire.
With nitrogen, your tire pressures will remain more constant, saving you a small amount in fuel and tire-maintenance costs. There will be less moisture inside your tires, meaning less corrosion on your wheels. You will not be able to feel any difference in the ride or handling or braking, unless your tire pressures were seriously out of spec and changing to nitrogen brought them back to the proper numbers.
Just wish it weren't so expensive per tire, or I would make use of it.
A bigger molecule I guess too for the small leaks.

[mmm666]

During winter, I set my tires to 35 PSI cold. I always monitor the PSI.

[bubbleguy]

I did a check with the physics I learned and still remember. For the air inside the tire to occupy the same volume (i.e., the tire has the same roundness) between summer (86 F) and winter (32 F), the tire pressure in winter should be about 10% higher. If the pressure in summer is 32 psi, then in winter it should be about 35 psi.

[carguy07]

The pressure in the summer and winter should be the same. Just check your tires outside when cold and you are good to go.

[N_Jay]

Yes, the pressure should be the same, but you have to add air as the temp goes down.

Nitrogen and "air" expand and contract at the same rate.

Nitrogen has less water and no oxygen, this reduces the "loss" of air, much of which is due to the water and oxygen reacting with the metal of the wheel and the oxygen reacting with the rubber of the tire.

The escape rate is about the same.

[refotsirk]

Interesting site to inform about the nitrogen and tire saving theory thereof.....moisture really seems to be the "badguy" in the tire/rim relationship...and fluctuating pressures. And reducing false alarms on the tire monitoring device...hmmmm.....

http://tirenitrogen.typepad.com/lite...oneReprint.pdf

[carguy07]

Honda's opinion:

Nitrogen Inflation: What’s Our Position?
Surf any automobile tire-related website these
days, and you’ll likely see something mentioned
about nitrogen inflation. It’s becoming a hot topic.
We’ve gotten a number of inquiries lately
concerning American Honda’s position on this
practice.
When it comes to inflating automobile tires, it’s
our position that ordinary, dry compressed
air—which is about 80 percent nitrogen
already—is the best choice. That’s because it’s
more readily available, and the benefits of using
nitrogen simply don’t appear to outweigh those of
using compressed air.
The practice of inflating tires with nitrogen really
isn’t anything new; it’s been around a long time.
It’s been commonly used on aerospace vehicles,
commercial and military aircraft, military vehicles,
race cars, and even heavy off-road construction
equipment. Here’s why:
• To meet rigid safety and performance specs,
the required tire inflation pressures are often
very high, especially in the aerospace industry.
The tire inflation pressure for NASA’s space
shuttle, for instance, is a whopping 315 psi!
• Nitrogen is an inert gas; it doesn’t combust or
oxidize.
• The process used to compress nitrogen
excludes water vapor. Water vapor can expand
if the temperature climbs above 212°F.
• Tires inflated with nitrogen leak slower over
time than those inflated with compressed air.
Automobile tires, on the other hand, are subjected
to an entirely different set of conditions. Here’s
why inflating tires with nitrogen offers no real
advantages:
• Although tires inflated with nitrogen leak
slower over time than those inflated with
compressed air, they still leak and need to be
reinflated to maintain proper pressure. If you
can’t find a place that offers nitrogen
inflation—and there aren’t yet all that many
places that do—your only option left is to
reinflate with compressed air. Doing that
drops the nitrogen purity.
• Nitrogen offers no better protection against
road hazards such as cuts and punctures. So
no matter what you inflate the tire with, you
still need to check the condition and pressure
of the tires at least once a month as
recommended in the O/M.
• Tires that are inflated with compressed air and
properly maintained offer the same fuel
economy, tread wear, and ride comfort as
those inflated with nitrogen.
• Nitrogen for automobile tires is produced by
nitrogen generators, which typically get about
95 percent purity. But to actually get that
level of purity into an automobile tire, you
would have to deflate and inflate that tire with
nitrogen several times. If you’re not careful
doing this repeated deflation and inflation
process, the purity level winds up being closer
to 90 percent (compared to the approximate
80 percent nitrogen already in compressed
air). Because of this, those claims of less
pressure loss with nitrogen aren’t valid.
So here’s the bottom line: Nitrogen is an ideal gas
for inflating tires in aircraft, military vehicles, race
cars, and heavy off-road equipment, but when it
comes to automobile tires, it offers no apparent
advantages over ordinary, dry compressed air.
Our advice to you: Just stick with the air you
breathe.

[whizmo]

Forgetting the nitrogen waylay for the moment, I'm in agreement with a carguy07 that while you do need to add air in the winter, you do it not to have a higher psi, you do it so you'll have the same psi in colder temps. IOW, you don't want more pressure, you add air to have the same pressure in colder temps.

Nothing wrong with running 35 psi, winter or summer. Slightly firmer ride, slightly better handling, slightly better tire and gas mileage.

And BTW, if you're talking about winter traction on snow and ice, lower tire pressure offers better traction. If you're worried about getting stuck, 20 psi will sometimes get you through when 30 won't. But since most of us are not on challenging snow/ice very long and need to continue to drive on bare pavement at high speed, its really not practical to run very low pressures except in emergencies.

- Mark