Hey everyone, I am thinking hard about making the leap to an '06 Mega cab with the Cummins engine and was just wondering what I could expect for fuel mileage while driving empty and while towing a 8000lb 5th wheel. Any info would be greatly appreciated.

 

Although my truck is not quite equivalent, I have been pleased with my fuel mileage. I drive easy, and on the highway rarely exceed 2000 rpm. My last fill , 660 miles on 33 gallons of fuel hand calculated. Overhead was off only .2. I was 80% highway. I have 12K miles on it and have yet to do any serious towing. I am still not sure if the engine is completely broken in. It seems to continually get better.

 

You will be majorly dissapointed initially with the millage. When I put mine on the road if Feb of this year had a hard time getting 14 MPG. Pulling my 5er got around 9-11 average. Now getting 19-21 highway empty. Remember to keep RPM around 2000 for best millage. Much over and it decreases rapidly. Haven't pulled the fiver much espically distance pulling so can't give you any numbers there, but expecting 12-14 when we go to Florida from Michigan shortly. I do use the Power Service and Marvel Mystery Oil mixture and did add a Quad towing box and air intake but think that mainly break in made the biggest difference. Quad box added 1-2 mpg and the mmo & ps mis maybe 1-1.5 mpg by themselves. I didn't begain to see much better millage till after 10K and another jump after 17K or so. Now at 28K and think it's finally broken in.

 

I don't know about towing with a fifth, but I am getting 14.5 empty on the hwy as well as in town. Truck only has 2000 on it so far. This is worse mileage than my 01HO and '05 had starting out. I know that the Mega-cab is a 1000lbs heavier, but still not impressed will mpg. I wish they still had 3.54 gears.