Safeway is changing its gas rewards program. Tuesday, it will launch "Power Pump Rewards" that allows consumers to earn 10-cents off a gallon when a shopping trip adds up to $100. In addition, they can save another 10-cents per gallon for every additional $100 spent. Bottom line, the rewards add up and could mean free gas. Additional details about Power Pump will be released Tuesday morning and certain restrictions apply, but the major differences from Safeway's old program appear to be in the fact that the rewards are cumulative, they can be earned when selected gift cards are purchased and certain prescription purchases will also apply. With the price of gas up more than 30 percent in the past year and now above $4 a gallon nationally, businesses are turning to gas card promotions like this to get consumers' attention and increase sales.