I'm curious if anyone is experiencing steadily decreasing highway MPG's as they put more mileage on their trucks. Just got back from a 550 mile round trip on mostly highway, and averaged a dismal 16.8mpg at around 75mph. I've got a Platinum FX4, leveled with 305/55/20 tires so almost stock size diameter. Just flipped 14K miles. City driving I'm still able to get over 20 on average, but I hit the highway and it drops like a ROCK. Overall I drive like a grandma but cruise between 75-78...
Highway MPG getting progressively worse
Highway MPG getting progressively worse