How common is improper tire inflation?

A study conducted in early 2003, 2005 and still in 2007 found that more than two thirds of cars in Canada have at least one tire that is either under or over-inflated. One third of all vehicles had three or four tires that were improperly inflated. This represents a safety risk to Canadian motorists, as well as significant expenses in fuel and tire replacement costs. The resulting increase in fuel consumption means that more greenhouse gases, which contribute to climate change, and other harmful emissions are unnecessarily released into the environment. ... more