Does filling my tires with nitrogen really improve gas mileage?

Possibly. The important thing is to make sure your tires are properly inflated, which does improve gas mileage. If you already check your tire pressure regularly, you probably don’t need nitrogen in your tires. The added benefit of nitrogen is that it contains no moisture, which is present with a standard air fill. The absence of moisture provides a more stable pressure resulting in tires that are properly inflated longer. So, if you’re not in the habit of monitoring your tire pressure once a month and you are driving around with under-inflated tires, then yes, nitrogen may help improve your gas mileage. Remember, whatever type of tire fill you choose, be it air or nitrogen, tire pressures should be checked every month as outlined in your scheduled maintenance booklet. The proper tire pressure for your vehicle is listed on the tire pressure label located on the driver’s door pillar.