Filled up in Roanoke and drove 152 miles to exit 291 (in the rain). Put in 4.1 gallons of gas, for a mileage of 37 mpg in the rain, with defroster on (and occasional breaking/slow driving due to rain, plus about 7 miles on I-11 to avoid an accident). But then "filled up" again at exit 40, and put in 1.5 gallons (for 50 miles), for a mileage of about 33 mpg. Average for those legs was 202/5.6 = 36 mpg. Maybe next time I'll just do the 202 miles straight and see what the mileage is.