Am I figuring this right? I've looked at the spec charts way too long trying to decide what will handle our fifth wheel in a single rear wheel version. I recently weighed our truck solo and hooked up to our fifth wheel fully loaded for a trip including the wife and a fat Boston terrier. It added 280 to the front and 3020 to the rear = 3300 lbs total. The total fifth wheel weight was 16,660 which includes the pin weight.

The 2 2020's I'm considering are the 7.3 gas F350 ccsb 4.30 rear end with an 11,300 GVRW and the 6.7 diesel cclb with a 12,400 GVRW. The gas has a max 4420 payload and the diesel is 4580. I subtracted 575 lbs from the max payloads to account for options (my KR lost 533 from max so I'm being conservative).

7.3: 4420 - 575 = 3845 - 3050 loaded = 795 lb cushion. (I lose 250 lbs because I would not have my 25 gallon diesel transfer tank on board.)

6.7: 4580 - 575 = 4005 - 3300 loaded = 705 lb cushion.

It appears either truck will work. I think the diesel long bed would be the best option but the cheaper cost of the gas is tempting if it performs well.

I am a little concerned that the best I could come up with for GVRW for the 7.3 sb was 11,300. That seems a little light.

 

Well, to start with, your range between stops will still be much better with the diesel, and the 25 extra gallons in the transfer tank. It seems you are omitting the range extending tank from the gas option to keep the payload viable.

 

Or perhaps because the availability aftermarket gasoline certified transfer tanks is nearly non existent?

Something about the volatility of gas, and liability for the tank manufacturer, as well as state and federal laws requiring carbon purge canisters to control the evaporative emissions comes to mind?

 

Right, I can only use the transfer tank with diesel. Both trucks will have the 48 gallon tank though but with the diesel I can have up to 73 with my auxiliary tank. I rarely use the auxiliary as we generally don't travel more than the 48 gallons will take us.

 

Shucks, that ain't math, that's arithmetic

Don't ask your wife to get weighed in, or there's gonna be trouble right here in River City!!

 

You notice I only said the Boston was overweight. Actually, after 48 years of marriage she's still beautiful.

My dilemma is I know the long bed diesel will probably be more efficient and give a better ride towing. The short bed 7.3 will probably not ride as smooth towing and I would bet the mileage would be 2 or 3 mpg less towing. The upside for the gas would be less cost initially, less cost for fuel and a better daily driver. This is my second dually and I'm really wanting something a little easier to maneuver in my advancing age but I want us to be comfortable and safe on the road also. A dually is way more than I need weight wise so changing to single is not an issue for me. Our fifth wheel is actually designed for a short bed but I am leaning toward a loaded Lariat 6.7 long bed or a Platinum.

 

I may be missing something.

Your 5er going down the road is 16,600 lbs.

You weighed everything -- wife, dog, you, 25 gal aux tank, hitch, and pin weight and it came out to 3,300 lbs. Get rid of the tank and it's down to 3,050 lbs. I'll figure that you, wife, and dog weigh in at 350 lbs. I'll figure your 5er hitch is at least 100 lbs.

That means that a 16,600 lb 5er only has a 2,600 lb pin weight? I think that's borderline unsafe load distribution as you're getting close to sub-15% on the pin. I think 18-22% is a more common goal.

I'd expect at least 3,000 lbs on the pin, 100-150 for the 5er hitch, at least 350 for me/wife/dog, and I usually have firewood and other gear in the truck for another 100 lbs or so. That's 3,500+, not 3,050.

But, either truck still works just fine. That's the fun part of going big. We could nit-pick several hundred pounds here and there ... and it's still in the noise level of that truck's capability/capacity.

Have fun.

 

The CCSB won't have a 48 gallon tank. It will have a 34 gallon tank.

 

Curious, why not compare both long beds or short beds?

 

^^^^^ I am with above. Why not compare longbeds. You could get a cclb srw gas just as easy as the diesel and have the 48gal tank then. Unless the srw long bed cant handle the weight of your trailer then it's a dually again anyways. The gas truck will have a better payload in any config.

 

I think there is more pin wt than stated. But still fine.

Long bed is the way to go. I would go diesel with the amount of 5th wheel.

I can see the attraction to the 7.3 but I am not so sure I would be the first to beta test it for Ford.

 

I'm a little embarrassed but thanks for pointing this out.

We were on our way to eat dinner with our daughter when it hit me. My math is wrong. I forgot I add my wife, the 25 gallon transfer tank, my hitch, a BakFlip bed cover, the Boston and a few other small things that will be transferred to the new truck. I need to add that stuff to the 3300. Now I'm up to 3800 pounds leaving out the transfer tank which I rarely use. That should make my hitch weight about 3050. The only truck that will work would be the long bed diesel with it's 12,400 GVWR. Now I've got to step back and rethink this. I could get an Anderson hitch which would cut off about 125 or so pounds. I would be under by several hundred pounds but I need to think about it. I may just keep the dually. Disappointing but it is what it is.

 

Yeah diesel would be better. Maybe he could test drive with 7.3 and let us know. Lol. I wish dealers would have trucks setup for tow tests.

 

I wish I could test drive and test tow a 7.3. It may be January before we hear much about it.

 

I know the 7.3l is a brand new engine, but aren't those who order the 2020 6.7 also beta testing? Brand new piston material and design, fuel system changes, new turbo controller, several other changes.

I'd say the only people not beta testing are those who buy the 6.2