The Environmental Protection Agency (EPA) is considering a proposal to adjust its greenhouse gas emissions test procedures to account for the switch from Tier 2 to Tier 3 fuel at commercial gas stations across the country. Consumer Reports joined consumer, science, and environmental advocacy organizations in sending a letter of support for the EPA to move forward with the adjustment, and push back on auto industry requests to forgo adjustment. Failing to adjust its test procedures would weaken federal greenhouse gas emissions standards, potentially costing American drivers up to $30 billion in added fuel costs.