If every car in America had properly inflated tires, we’d cut back on 3-4 percent of our oil consumption. Unsure of how to check your air levels? Umbra never tires of helping out.

[youtube http://www.youtube.com/watch?v=mQe2pXNf-XI%5D

Note: Grist’s Screw Earth Day campaign may be long over, but we stand behind the sentiment.

This year marks the 10th anniversary of our Ask Umbra advice column, and to celebrate, we’re pulling a favorite gem of eco-advice out of the archives each week.