Fifth Wheel/Diesel mpg

[Stewart123]

My husband and I are looking into a fifth wheel for our retirement camper. We hope to have our minds made up by January 2018. He wants to get a 2500 series diesel truck. Fifth wheel would be in the 8500 to 9000 lbs range. For yucks, I'd like to know what people are getting, mileage wise, pulling a fifth wheel as opposed to a travel trailer in the 6,500 lbs range? Any insight would be helpful. Thank you.

[portablevcb]

We full time and our truck is our only transportation. I did not want a dually for that reason. So, we just kept our 2500 and I added overloads (Timbren in this case but airbags would work too).

The trailer GVWR is 11,000lb and we are over 10,000lb ready to travel. We do not want a bigger trailer (this is our third RV).

Diesel vs gas. If you are using the truck as a daily driver and towing less then I'd recommend a gasser. We almost traded the diesel for a gasser this summer. If you tow a lot of miles you will like the diesel.

Mileage. Interesting topic. When towing our old 24ft fiver we got around 12mpg. When we got the new fiver we were getting about 11mpg (Western states, higher altitudes). So, had to have a turbo replacement and in doing so upgraded it and deleted emissions stuff. Now we get about 13mpg at higher alt and 14mpg nearer to sea level.

As a kind of comparison, when we towed the little fiver with a 2nd gen Toyota Tundra we only got about 8mpg (at altitude).

My recommendation if you get a gasser is to make sure you have a bigger gas tank, eg 35gal or more. Why? Gas stops are a PITA in a lot of places.

Last, maintenance for a diesel is higher than a gasser. They hold a LOT of oil 🙂

I'd not worry about mileage and buy the truck you want after test driving them.

charlie

[Stewart123]

jalichty wrote:
Just got back from a trip up to Grand Teton towing our 30' FW and a 19' boat up into and back out of the mountains. Small amount of sightseeing, probably 50 mile or so. Total trip about 450 miles and console tells me we got 12 MPG overall towing this set-up. Took a long trip, 3,800 miles a couple of years ago with about 3,500 towing the FW, no boat, and hand-calculated we got 12.6 MPG for the entire trip. Never once had frazzled nerves towing our FW, even with our GMC 2500HD rather than a 3500 one ton.

That's great! Good stuff

[Stewart123]

JAC1982 wrote:
We just got roughly 9mpg on a trip from home (near Denver) to the Wyoming side of Flaming Gorge, driving on I-80 with some wind. We were probably at least 15,000lbs loaded up.

And yes, get the 1 ton if you can, it's not much more than the 3/4 and will open you up to pretty much anything other than the very largest triple axle 5th wheels.

Thanks! We do plan to stay on the smaller fifth wheel size, under 9 lbs dry. We know that'll be plenty of room for us. We have 15' TT now for the past 6 years since we aren't retired quite yet. From what I'm reading from everyone, I'm going to just plan on an even 10mpg as a standard figure. If we get more, great! lol

[jalichty]

Just got back from a trip up to Grand Teton towing our 30' FW and a 19' boat up into and back out of the mountains. Small amount of sightseeing, probably 50 mile or so. Total trip about 450 miles and console tells me we got 12 MPG overall towing this set-up. Took a long trip, 3,800 miles a couple of years ago with about 3,500 towing the FW, no boat, and hand-calculated we got 12.6 MPG for the entire trip. Never once had frazzled nerves towing our FW, even with our GMC 2500HD rather than a 3500 one ton.

[Spearson]

Vacation last month from South Texas to Colorado. Over 2500 miles.
Me w a 17 3500 GMC Dually and a over 40' and 15k 5er got 10.6 mpg

Friend w same rv and a 2500 GMC got 11.1

I was good at the end of each day, friends nerves were shot.

Peace of mind cost .5 mpg

[Stewart123]

Stewart123 wrote:

Etstorm wrote:

troubledwaters wrote:

rhagfo wrote:

troubledwaters wrote:
The difference in mpg due to weight is negligible. It's the size of the front that makes a difference.

I'm going the opposite direction next time I get a new truck. I'll be ditching the F250 and getting a properly equipped F150 Ecoboost. Best of both worlds. No problem hauling my 8,000 lbs trailer and great gas mileage as a daily driver.

Going to Politely disagree with you on this.
Many on this and other forums have posted that when going from a lighter TT to a heavier 5er, with the same TV have found the 5er got better fuel mileage. This is likely due to the 5er being closer to the cab and less wind resistance.

Etstorm wrote:
I had a 28' TT and pulled with a F150 ecoboost. Got 7-9 mpg

I thank you for your input and information!

Now pulling a 38' FW with a Ford Diesel and get 9-10 mpg

JAC1982 wrote:
Yup we had similar numbers when pulling our old toyhauler with an F150 Ecoboost. Plus you really feel the weight pushing you around because the truck is light.

Combined town and highway I get 17
Highway only not dogging it 22-23
Not bad for a large truck 4x4

Ya'll failed Reading Comprehension 101
"...great gas mileage as a daily driver."

Thanks all; good to know!

[Stewart123]

phillyg wrote:
Given a choice, and not knowing what 5th wheel you're getting, a one ton truck would be your best choice. Fuel usage will drop below 12mpg when you're towing. A 9000lb will be fairly small so be prepared to live in such small quarters.

I think we'll be fine in the 9000 lb. Tent camped for 30 yrs; owned a pop up a short while and now a 15' tiny hardside for the past 5 years. We will feel really large when we move to a 5th wheel in the 8,000 lb range. lol We tend to go small; home is only 1100 sq ft and we have more room than we need. Appreciate your comments and everyone has give such great advice!

[Stewart123]

pinesman wrote:
In my opinion, I would rather drive a dually any day, even if it means parking at the end of the parking lot. One thing I don't think anyone has mentioned is the speed you plan to tow. I get better mileage towing on rural two lane roads than interstates because I go slower. The bigger the frontal area of the trailer, the more speed seems to make a difference. We went on a 7500 mile trip out west last summer with a '07 3500 Duramax-Allison combo pulling a 12,000 lb. fiver and averaged 11 mpg while we were gone. A couple thousand of those miles were sightseeing without the trailer.

That's good to know! I agree! I like off the road better than highway miles; it's scenic and you see the real area.

[pinesman]

In my opinion, I would rather drive a dually any day, even if it means parking at the end of the parking lot. One thing I don't think anyone has mentioned is the speed you plan to tow. I get better mileage towing on rural two lane roads than interstates because I go slower. The bigger the frontal area of the trailer, the more speed seems to make a difference. We went on a 7500 mile trip out west last summer with a '07 3500 Duramax-Allison combo pulling a 12,000 lb. fiver and averaged 11 mpg while we were gone. A couple thousand of those miles were sightseeing without the trailer.

[RollandB]

I get my best mileage when towing my rig. The reason why it's the best is I'd rather be towing it somewhere than running empty on the freeway. For the setup in m signature the cio,outer tells me I average about 11-12 towing, 20 running empty .

I completely agree with bypassing a 2500 in favor of a 3500. No matter if new or used they aren't that different in price

[JAC1982]

I dunno, we only got around 17-19 with our old 2013 EcoBoost... 21 on one road trip when we had a strong tailwind 🙂 So, not that great, and it wasn't very good at hauling our old toyhauler (not the current one we have now). To me, the trade off to have a truck that was better at hauling was worth the gas mileage trade off. We get 14-15 in our DRW now when not pulling the trailer.

Now, my daily driver is a 2016 Explorer Sport with the Ecoboost and I'm lucky to get 22 combined city/highway. I got it up to 24 when doing a road trip with long stretches of highway. So not exactly a gas hog, but not what I'd consider "great" gas mileage either.

[Etstorm]

troubledwaters wrote:
Combined town and highway I get 17
Highway only not dogging it 22-23
Not bad for a large truck 4x4

Ya'll failed Reading Comprehension 101
"...great gas mileage as a daily driver."

[Toolguy5]

ScottG wrote:
I agree with DTR, skip the 2500 and go 3500.
The ride isn't really any different and you would be shocked how fast you can eat up the GVWR of a 2500.

I agree skip the 250/2500 and get a 3500/350

[JRMunn]

I have more experience with ag trailers, and am now pulling a 5th wheel with a 2008 Dodge 2500 that has a 6.7L diesel engine and 6 speed automatic with both tow-haul and exhaust brake options. I don't know what conditions you will be facing, but it sounds like a lot of travelling so you will be seeing a lot of different situations. Trailer weight makes a difference going uphill where mileage will be much worse. And you won't make it all up going back down, where more weight will mean you need better brakes. And brakes are important along with gears to help hold you back in both automatic and standard transmissions. Diesel engines by themselves don't provide much braking, so some sort of exhaust brake would be very helpful in the mountains. On flat ground, as others have said, air resistance (mostly from the front profile of the trailer) has a bigger effect on mileage than weight. But you still need to stop. And keep in mind that speed makes a big difference in mileage - mine really starts to drop off, whether pulling or not, above 60 mph. I haven't driven enough with the travel trailer to say much about curves, but I expect this is where you will see the biggest benefit from a larger truck along with better brakes and handling in general. From reading in this forum, it sounds like there are also differences in handling between trailers of similar size.

If you are worried about mileage, cost must be a factor. Depreciation has been mentioned, and the difference in cost between new and used for both trailers (especially) and trucks is large. And, again from reading in this forum, new isn't always better, which adds something else to think about in an already complicated decision. Now getting back to your question, I get about 17 mpg in mixed daily driving and averaged about 13 pulling 4 horses and a large stock trailer on my longest trip from California to Wyoming and back. Most of this was on I80, and the load was probably lighter than many 5th wheel trailers. From what I see above, I should be happy about mileage. Whatever you get, enjoying your travels is most important.