I have the same truck as Executor485 and am seeing the same. I have been doing mostly local driving recently and the little computer says 13.5 avg

 

Just finished a 1500 mile road trip. 90% highway with cruise set at 80 mph. Averaged 13.6 in a 6.2 Raptor. Not good but now as bad as I thought it would be.

 

I have a 2011 HD with 2" level and 33's and i get around 11mpg around town and 16.2mpg on the highway with the cruise set on 70.It was a little better before I put the chrome 22's and the terra grapplers but its not a prius so I dont really care if it sucks gas.I love the 6.2L!!

 

What? I forget where I saw it, but people are already marketing exhausts for the EBs and a few people are saying they picked up 30 rwtq with them.

You CAN remove the resonators and no they wont overspeed the turbos. I don't see how any change in exhaust is going to cause overspeeding of the turbos, they're only pushing 13 pounds max, it really isnt much compared to some cars pushing 28-35 pounds

 

Thats not too bad considering you were probably hovering around 2400 RPM's or so and it's a meaty truck with monster tires. One of my in-laws was complaining about his lifted Chevy truck getting less than 10mpg on the highway on our trip to Colorado. I'd take a Raptor any day over a lifted Chevy or Dodge.

Gotta love people who dont understand turbo'd cars. Obviously changing the exhaust will cause the turbo's to overspool, the steering wheel to vibrate, and will allow you to travel back in time when you reach 88mph.

 

I must be doing something wrong. I have a stock 2011 HD and I'm only getting 14.6 MPG setting the cruise control at 70. At 75 I was only getting 13.8 so I slowed it down. Every day I have a 30 minute highway commute each way, all at highway speeds. This is in Texas where everything is flat except for the women.

 

I'm in TX as well. Have you reset your trip computer while doing the commutes? If I sit at all my mpg reading is much lower.
Also, how many miles you have on it? Sometimes it takes some breaking in.

 

I wouldn't consider the computer to be reliable. Paper style math is the only way to go for real calculations. That way you can just add one more step to adjust for larger tires. The computer can't do that unless you tune it.