Currently we have an F250 4wd supercab 7.5L gas engine with a 2008 Northern Lite 10-2 camper with Rancho XL9000 and fast guns. Our truck has no problems with weight of camper as it rides perfectly level, but we have to pack light, minimal water, and basically carry about 5 gallons of gas in rear tank to stay within tire ratings. We thought about doing upgrades to tires but gross weight of truck is still rated at 8800 pounds and of course are over that so are wanting to purchase a 2015 F350 dually. The dilemma is whether to go the gas engine or diesel as we will want to flat tow a jeep in the future as well. We know the diesel is the powerhouse. What we want to know from all of you is realistic mileage that you are getting with your setup. Please post mpg, speed that you are traveling to achieve this, truck brand, size, engine, etc and what camper. We appreciate your input to this and fully understand about weight ratings and pulling lots of weight as we have had large travel trailers for many years.

The biggest issue is where and how far are you going to tow. A diesel is going to get better mpg under a large load IE: headwinds, steep hills, heavy towing. If you are on mainly rolling hills, light load, short trips either engine will be fine although gas engines are probably better at short trips. If you think that at anytime in the ownership life of the truck you are going to go to a heavy camper and tow heavy the Diesel in the right choice hands down. My older diesel gets pretty much the same mileage towing heavy or no trailer 13.5 on the highway at the speed limit and 12 in the mountains. I scale with just the truck and camper between 12,000 and 13,000 depending on how many toys are loaded on board. my horse trailer scales between 6-8000 depending on how many horses and hay is on board

Mainly long trips = Diesel. For shorter trips and a daily driver the gas makes more sense. The diesel will get better mpg but it takes a lot of miles to make up for the initial cost and the maintenance costs. I have both a new 6.2 Ford gas and a old school 7.3 powerstroke and the powerstroke does about 1/3 better on fuel than the 6.2. I only do about 12k a year so another diesel wouldn't make sense for me. Now for my question. Why a dually? Why not a F350 SRW with the heavy payload package. I think mine is rated around #10,800 which is plenty for most campers. Dually is good if all you do is haul but they are very un-handy when it comes to everyday use.

10,800 might be enough for most campers (I disagree with that, but let's assume you're right), it's still not enough for any decent amount of tongue weight. I guess when flat towing, that really isn't a huge issue, but a dually allows for a bigger camper and possibly more cushion for tongue weight.

Going to a single axle verses a dually would force us to literally Not to load much in the camper and in fact according to the charts, the single axle highest payload will not accommodate the camper I have when loaded. Our weigh ticket with two adults, 2 full tanks of gas, about 25 gallons of water, and gear ( no AC, awnings, or generator) puts us about 3600 pounds. We will be adding roof AC this spring and possibly a generator. Certainly not enough carrying capacity on new truck even with gas engine and certainly wouldn't have an option to ever upgrade to a larger camper and so dually it is. The dilemma is gas verses diesel and mpg based on your truck/engine and speed so we can decide which way we want to go. We appreciate all of your responses.

The rig in my sig line gets 18-20 mpg highway empty and around 14 towing a 4,500 lb. jeep. Mountains drop that number to around 11-12, but as said before, if mainly towing on flat terrain short distances, gas might be the ticket. I'm very happy with the performance of our diesel dually for carrying a nearly 5,000 lb camper while towing.

Buying a new truck | Good Sam Community

bighatnohorse
Explorer II
Mar 04, 2015
joe123 wrote:
Buy the dully carries a heavy load much better with little to no side to side, get the diesel the power is always nice to have if its needed, I cant talk about the ford as I have a dodge I ton dully diesel with a full load and flat towing my tracker I get just over 14 miles per gallon if I keep my speed under 55 miles per hour, I have a friend with the ford he told me his was around 13 depending on his foot.

That sounds about right. . . a recent test with my new Ford dually diesel resulted in 13.4 at 65mph dropping to 10.3 at 70 mph! (with camper loaded 15K pounds on the ground).
joe123
Explorer
Mar 04, 2015
Buy the dully carries a heavy load much better with little to no side to side, get the diesel the power is always nice to have if its needed, I cant talk about the ford as I have a dodge I ton dully diesel with a full load and flat towing my tracker I get just over 14 miles per gallon if I keep my speed under 55 miles per hour, I have a friend with the ford he told me his was around 13 depending on his foot.
arto_wa
Explorer
Mar 04, 2015
On a highway we get 15 mpg unloaded and 12.4 mpg with the camper on, under good driving conditions & not speeding - checking manually.

AT and 4:10 rear axle.
Reality_Check
Nomad II
Mar 04, 2015
8.... Usually pushing it hard; 70 max.

At 18k, I get about 8.

At 30k, I get a bit less...like 7.6

I saw 14+ once... an empty truck on a long stretch of 5 states.

Wife and I decided to spend it instead of dying with it...
deltabravo
Nomad
Mar 04, 2015
Grit dog wrote:
Don't even waste your time with a gasser in a dually with the loads and trailers you pull, especially at altitude. Especially if you plan on selling it, because very few will want a HD dually with an anemic engine. Resale will be terrible.
Seems like you'll keep the truck a long time as you're rockin a 25 year old truck currently. Another reason to get the right truck the first time.

That pretty much sums up my thoughts on the gas vs diesel too.

To me, it does not matter one bit of difference that the diesel truck costs more in maintenance. The ease of towing far outweighs that difference.... so much so, that I own two diesel trucks.

If you tow with a camper on the truck forget, about a gasser.

One of the things I do with the 2006 truck is transport RVs. All the transport companies are just short of demanding that their drivers have a diesel truck - that shows how important and better a diesel truck is for hauling a load.
slickrock_steve
Explorer
Mar 03, 2015
Once you go diesel, you won't go back!
And as to the exhaust brake? GET IT! You will be so much more relaxed in mountains, and probably can stop quicker than with out one on the flat!
I have a 2005 Ram, with auto, 3500, quad cab. It gets a reliably accurate 19MPG empty at 65-70, and 12-15 MPG with my 4000 lb camper. When the camper is off, and I have my 11,000 lb 4 horse, with living quarters gooseneck on, I can still hold 65, and still get at least 12 MPG. with NO DPF!!
The maintenance on a diesel is not more than a gasser, as you don't have to change the oil as often. I use "Oil Analysis", and "Blackstone" says my oil can go an easy 15,000 miles. I do change the fuel filters more often, but I have two filters, and want to save the injectors.
805gregg
Explorer
Mar 03, 2015
12.5 MPG 2003 Dodge 3500, with a Lance 1071 4000 lb camper, figured by hand, everyone knows the onboard computer is inaccurate, get an older used truck and avoid initial depreciation and DEF (diesel exhaust fluid injection)
trailgranny50
Explorer
Mar 03, 2015
We've been crazy blessed with our 2004 Duramax dually over the years. It consistently gets 15.1 mpg highway empty and no tailwind down to 15 loaded with camper mountains or flat not towing. Haven't towed anything with camper on but will this spring. However is only a one horse tandem axle and boat is just a small 10x5' John boat. Still pretty good mileage. We have, over the years, done some front end work, injectors, and a VSS module replacement but that's it. Very fortunate. It had always been a work truck till this past June, when we picked up the camper, hauling Masonry tools, scaffolding, tractor, bricks, blocks and cement. Not exactly a sheltered life. Like I said we've been blessed with a really good truck. Hopefully it will last well past it's now current 170,000 miles. We get it serviced more frequently than recommended and if it squeaks, or leaks it gets fixed Pronto.
PRodacy
Explorer
Mar 03, 2015
We get about 12 mpg with the camper and towing our Wrangler if we stay at about 70 mph. At 75 it drops to around 10 mpg. The truck (2012 GMC dually) has 3.73 gearing, 6.6 l diesel, Allison transmission. Without the Jeep or camper we get about 18 at 75 mph. I've driven gasses with comparable loads and while they are OK on flat land, they're not very good in the mountains, and the diesel is way better even on the flats. Like others have said, consider the resale value of a diesel compared to a gas engine. Some threads say that diesels are way more expensive to maintain, but I haven't found the difference to be significant especially when you look at the money you have invested in the truck, camper, jeep, etc. I'm fully sold on a diesel for use you're considering.
Wind_Surfer
Explorer
Mar 03, 2015
A lot of good replies and information provided. Glad to see you are knowledgable on weight ratings. I also think a dually will drive sooooo much better with a load, especially in wind or mountains.

My truck; 2011 Dodge 3500 dually quad cab 4X4 diesel (6.7), automatic. Mileage 10-12mpg. Now those numbers are pulling a 14.5k fiver, I get around 13mpg with the TC (2500 gross). I tow at about 60 to 65 max mph (again, read the tire side wall on trailer tires). Camper, usually drive the speed limit unless it is insanely high like out west or Texas.

For me, the hardest choice about the truck was what gearing for the rear end. Dodge offered a 3.50, 3.73 and a 4.10 gear ratios if I recall. I finally decided on the 3.73 and it has worked very well with the automatic transmission gearing.

BTW, make sure the truck has an exhaust brake. It is unbelievable, you won't believe you towed without one!

Cheers