Stan Moneymaker needs 13 gallons of gasoline to top off his automobile's gas tank. If he drives an extra eight miles (round trip) to a gas station on the outskirts of town, Stan can save ?$0.06 per gallon on the price of gasoline. Suppose gasoline costs $3.30 per gallon and Stan's car gets 24 mpg for in-town driving. Each mile that Stan drives creates one pound of carbon dioxide. Each pound of CO2 has a cost impact of $0.03 on the environment. What are Stan's savings per mile for the eight mile extra trip, including the effect of environmental costs?