What is the average you guys getting on 05 3500. Last trip I got 15.5 cruise set on 300 mile trip. I get about 10 towing.

 

There are many variables to your question. The truck in my sig has gotten 19-20 mpg on the highway if I stay at 65. At 75 it drops to 17 mpg and at 80 it is only about 15 mpg. When towing 12,000 lbs. on a flat bed with little wind profile I stayed above 14 mpg but towing an enclosed trailer of the same weight dropped to 12 mpg.
Hope this helps

 

What tires (& pressure) you running? I would think you should be at least in the 18 mpg range with your set-up empty hwy.

 

I generally run 18-20. My best mileage was 24 going into New England on 50-55 mph back roads. The trip home was 21.

The worst I've gotten was 11 in two different trips once in West Texas and once in Wyoming. Both times I was going 80 mph, A/C on at 100 degrees outside, four passengers, and towing a 7,000 lb travel trailer. Each time the fast speed was for only a day. Traveling to Alaska and back, with four passengers and same trailer, with some side trips, I averaged 14.9 over 12000miles.

 

My 2005 2500 2wd 4 door short bed gets 22.5mpg at 65mph. 75mph on the interstate gets 20mpg. At 70mph it will hover around 21mpg. 55mph gets about 20mpg. These numbers are empty/family/luggage type of travel and no heavy loads or pulling. Truck is bone stock factory.




47

 

Stock general tires 65 frt 55 in duals empty. That was with draggy wheel bearing replaced fresh alignment air filter cleaned valves recently adjusted quad race box on level 3 usually stays there and two stroke oil in fuel. I have never got better than 11 mpg towing but I'm at 22,600# and I can't resist passing every furd I can find. My exhaust sounds best bouncing off the side of a furd.

 

I have my smarty set to 90hp with timing and 35" tires. I just did a trip through the mountains and averaged about 18mpg... I was driving 120-140kmh the whole time. Lots of 6-8% grades.... the two big ones each way were about 20km's of 8%
Driving around town and highway I get 18-20mpg.
Tire size was adjusted in computer.... but it is the lie-o-meter so I'm probably a little lower

On my 06 I had a standard and 37" tires... a lot more power. Basically everything but twins. The lie-o-meter was between 22-24mpg usually.

It's weird yours is so low

 

You need to hand calculate. My overhead say I get 23 when it's really 15.

 

When I was stock... and just a smarty otherwise... I joined the 700 mile club. I could get up to 24mpg at 65mph with stock tires under ideal conditions.

Man I wish those days were here again... along with $2.00 fuel... (who'd ever though we'd WISH for $2.00 fuel???)

 

These fuel mileage threads are lame....

Overhead fuel mileage readouts vs. hand calculated.
US gallons versus Canadian gallons.
700miles on 1 tank. How big of a tank??!!
Even some metric thrown in.

24MPG US, 35" tires, 4x4 dually, running 75mph with cruise control on.... For surrrrreeee!!

 

If you run them at max pressure, you'll pick up 1-2 mpgs (but the centers might wear faster). Also forgot to ask about if you're air filter is clean, makes a difference too.

 

I have a banks cold air intake. It is an oiled filter but they should know what they are doing.

 

I had an oiled S&B on my '03. Returned great power and mpgs for about the first tank after I cleaned it, then not so much. Eventually put the stock one back on with a deeper filter profile. But that's just personal preference.

 

Not sure on HWY mileage yet (haven't been on a trip not towing yet). But hand calcd with 4.10's in the truck in my sig I avg 15.5-16 in town. I got just under 12 towing my Comanche from Florida to Kentucky and back...about 8K total trailer weight with jeep, trailer, and 4 wheeler in bed of Comanche. (plus front bumper of Comanche when on trailer is = to roof height on dodge...so AIR BRAKE) plus my family of 5 and a 4 wheeler in the bed of the dodge as well. Probably 16-17K total gross. Avg speed of 70 MPH..sometimes 75 sometimes 35 (rubber neckers looking at other rubber neckers)

My '04 when I had it new in '04 with the 6 spd and 3.73's got 18 city and 22 hwy empty. BUt that was before this crappy fuel and again with 3.73's (nearly identical in every other way to my current truck).

My overhead on my '04 used to be quite accurate...but this one lies. It tells me I'm getting 18.5...this is reset with a full tank...and when I hand calc it's more like 15.7!!