Currently in the Yellowstone NP area. The speed limit in the park is generally 45 mph with some areas at only 25-35 mph. On this last tank of gas, I knew it was going to be good when cumulative readout said 43.7. Traveled 389.1 miles, filled the tank with 9.444 gallons and average speed was 35 mph (per the readout). That came to 41.2MPG! One thing to note is that due to the altitude (8500ft), I've been using 91 premium. Please click on my Fuelly sig below to see my stats.