The first real cold snap of the fall turns on a lot of tire pressure lights in Fargo and Moorhead. Nitrogen won't stop that, but it does help your tires hold their pressure better the rest of the winter. Here's what it does, and what it doesn't.
What a nitrogen fill is
The air in your tires is already about 78% nitrogen. The rest is mostly oxygen, plus a little water vapor. A nitrogen fill replaces most of that oxygen and moisture with more nitrogen.
Why it helps tires hold pressure
Every tire slowly loses pressure through the rubber, and oxygen works its way out faster than nitrogen does. In a year-long test by Consumer Reports, tires filled with nitrogen lost about a third less pressure than tires filled with air.
Nitrogen is also dry. Air from a compressor carries some moisture, and that water stays inside the tire. A dry fill means less moisture to rust steel wheels or corrode valve stems over time, and less oxygen working on the rubber from the inside.
What it means in a North Dakota and Minnesota winter
Cold lowers tire pressure by about 1 psi for every 10 degrees the temperature drops. That's true for nitrogen and air alike. A tire set to 35 psi in a 70-degree shop will read close to 26 psi on a 20-below morning.
Nitrogen helps with the part you can control. Your tires start the winter at the right pressure and lose less on top of what the cold takes, so they spend fewer days running low. Low tires wear faster on the edges, use more fuel and don't grip as well on snow and ice.
A few habits matter more than what's in the tire:
- Check your pressure once a month and after a big temperature drop.
- Check it cold, before you drive, and use the numbers on the sticker in the driver's door jamb, not the number on the tire.
- If the pressure light comes on during the first cold morning, it's usually the cold, not a leak. Fill the tires to the door-sticker pressure. If the light keeps coming back, stop in and we'll check for a leak.
- Topping off with regular air is fine. It just dilutes the nitrogen a little.
Who gets the most from nitrogen
- Pickups, trailers and equipment that sit for weeks between uses.
- Farm and commercial tires that carry heavy loads, where steady pressure helps them wear evenly.
- Anyone who doesn't check their pressure often. Nitrogen gives you more room for error.
If you check your pressure every month, the difference is smaller. Nitrogen isn't magic, but in a place where winter already pulls pressure down, keeping the rest of the loss low is worth it.
Nitrogen at Fargo Tire Service
We fill tires with nitrogen at the shop at 2020 Main Ave in Fargo. No appointment needed for tire work. Ask about it when you buy tires, or read more about nitrogen inflation.