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.

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

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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.

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