This Earth Day, Volkswagen Canada wants people to know that a little air in their tires can make a big impact on the environment. Volkswagen will be presenting a 30-second television ad, featuring a slowly inflating globe. It culminates with the message that “By checking our tire pressure regularly, we could save 24 million litres of gasoline a day.”The ad is just one part of the Volkswagen’s Worldwide “Think Blue” program, which is based on the notion that environmental protection and automotive progress should go hand-in-hand.