With approximately 8,000 miles on vehicle, it began to buck and decrease speed once hitting the set cruise control speed. Later in the road trip, with 30 miles left until empty the vehicle shut off on the highway. Vehicle would not start and headlights would not illuminate. Roadside assistance provided gas can. Put approximately 5 gallons of gas in vehicle and range increased to 31 miles to empty. Vehicle then started and was able to be driven home.