The engine in the Chrysler is the 2.7 and I rarely run the speed limit. Half the trip is in Missouri where the speed limit is 70 for the most part and I had the cruise set on 75. The route I took in Kansas the speed limit varies from 55 to 65 and I had the cruise set to 5 mph over. The gas is 87 octane with up to 10% ethanol and I used 17.4 gallons round trip. Take out the ethanol and it would have been higher.