nvrenuf

Yes, another mpg thread....

I have an 06 2500 Mega Cab 4wd, 6 spd with 185k miles, it is bone stock (no power mods, nothing) with the exception of an SB single disc clutch and 12.50x35 all terrain Toyo's.

I've owned the truck since new and it's always consistently averaged 14-ish mpg in town and 16-ish on the interstate (unloaded, cruise on 70).

My issue - last weekend I towed a truck about 500 miles (2800 lbs trailer + 5500 lbs truck), cruise on 68-70, the route is mostly flat except maybe 100 miles of hilly interstate around Birmingham Al. and the truck averaged 7.5 mpg's (hand calc, 2 tanks). Does this sound normal? I thought it was low and the truck otherwise drives / feels normal as always.

Typically, I never haul big loads and only occasionally pull a small 2 horse trailer with 1 horse (4k lbs) and that usually gets around 11-12 mpg. I knew pulling the heavier load would certainly effect mpg but was surprised to see it at half the usual average.

Danavilla

Speed, speed, speed! I rarely get less than 10MPG pulling my 11K fifth wheel but have learned, after many K miles that MPG drops dramatically over 55. As much as 1 or 2 MPG for every 5 MPH over that speed. Your larger than stock tires make the truck work even harder.

nvrenuf

Thanks for your input! I've played the big tire game on my none daily drivers for years so I do understand their adverse effects. In fact, this haul has me considering going back to a 33" next time. Your experience answered my question, I expected the mpg's to fall some with a much heavier load than I typically pull but man was I surprised.

If pulling at 55 mph could get me back to 10 mpg's I'd seriously consider it but, man, I bet you'd get the stink eye on the road. LOL

Mikeske

I learned this lesson 20 odd years ago about speed. I was using at the time a 1996 Dodge Ram 2500 V10 gasser and it averaged 11 MPG unloaded and towing our 10,000 pound 28 foot fifth wheel it averaged 7 MPG if I did 65-70 MPH. Once I took the speed down to 55-60 MPH I was getting 9-9.5 MPG. Today with my 2004 Dodge Ram 2500 Cummins I average 15-17 MPG at 70 and if I average 9-11 MPG when I tow with the same fifth wheel that I have used for the 20 plus years. Dropping the speed down to 55-60 with the Cummins and fifth wheel I average around 14-15 MPG and 18-19 unloaded. In my home state of Washington the limit for vehicles towing a trailer is 60 MPH on the freeway and that is what I do kept to the speed limit and saving fuel. I am now retired and my wife and we travel a lot so anyway I can a bit on fuel I do it as we have all the time in the world. Just think of the wear and tear on the brake system and transmission pulling and stopping all that weight from higher speeds.

Sure I get the evil eye but I just keep my butt planted in the right lane and let the speed racers go by us in the left lane. It also much easier to control that trailer if you are lower speeds. Living in a state that is mountainous you learn that mileage here will be lower until you get to the flatter parts of the country. Just remember to slow down and enjoy the scenery.