Can nitrogen tires be filled with air?

The benefit isn’t as great as nitrogen-filled tires, but there is still benefit with a mix. The reason is that a mix still has less water vapor and oxygen than tires that are entirely filled with air, so the some of the downside of that type of tire is removed. The benefit of the mix would apply to all types of tires: motorcycle, bicycle, managed fleets etc. The only way to retain that benefit, however, is to fill your tires with nitrogen from that point forward. read more

Yes, you can put regular air in tires that have nitrogen! Topping off with air doesn't fully negate the benefits of nitrogen tire inflation. read more

Some may be filled with 100% nitrogen. Most are filled with air, which is 78% nitrogen. Unless you are racing on a track where even a .0001% advantage might lead to a win, or are filling a tire on some aircraft, you should simply use regular air in your tires. read more