MPG with and Without tonneau cover on 2022 tundra

Averaged 20.2 to 20 mpg without cover. Installed trifold cover and checked mileage and was pleasantly surprised. Traveled 226 miles on 10.48 gallons and averaged 21.56 mpg. That is 1.2 mpg better than without. Did not change my driving. I like to hear the turbos if you know what I mean. Just thought you may want the info. Have almost 3000 miles on it. Seems to be getting better and better. That is every day driving. Mix of 25 35 45 and 55 mph. I usually drive 5 over limit.