F350 SRW Enough Truck

[bjkb1f]

Hi all. I currently tow a 7k lb TT with an F150 and we’re thinking about upgrading to a fifth wheel. Looking at the Sabre 37FLL - link with specs below.

This is totally new to me and I don’t want a dually or a diesel. So, my question is would a 2021 F350 gas/SRW be enough to tow this camper for 8-10 trips a year mostly within 3 hours of home? It would be extremely rare that we would be in any mountains.

Our TT is currently about 1,000 lbs more than dry weight, so assume we add a bit more than that to the new 5’er. I don’t think we’d get anywhere near the 2900 lb CCC. I’d assume pin weight would be 3k at the most.

Sabre 37FLL

[Grit_dog]

^Chrysler probably got a deal, financed by Bosch since GM dumped the CP4. They were “on sale” so to speak.
At least it only took Ram 2 years to realize the blue light special cp4 was not the bargain it appeared to be.

[Cummins12V98]

ognend wrote:

Cummins12V98 wrote:

ognend wrote:

Cummins12V98 wrote:
I was referring to my 15 RAM/CUMMINS. My coolant interval is 150k same with valve adjust.

I also understand being able to easily work on my engine compared to others.

Sorry, when I say "newer" diesels I mean the CP4 diesels, don't know much about Cummins. The official coolant interval per Ford manual is 105K miles I think but people are doing it at 30-50K all in the hope that the engines will last what the old 7.3Ls did. It's become stupid at this point, over maintenance and all but apparently the consensus is that either they work all day every day or if you are a casual pavement princess or low-milage tower, then excess maintenance is in order.... what do I know....

For some unknown reason Cummins went from the CP3 to the CP4 in 2019 & 2020 and back to CP3 2021.

It's not an unknown reason - the reason is the excessive amount of CP4 failures.

NO, my point was why did they go to the CP4 in the first place.

I did attend the TDR May Madness in 2018 when a Chrysler Rep said the reason they were going to the 4 was because they couldn't get enough pressure out of the three with the power upgrades for 2019. That was obviously a "Barbra mStreisand" statement.

[ognend]

Cummins12V98 wrote:

ognend wrote:

Cummins12V98 wrote:
I was referring to my 15 RAM/CUMMINS. My coolant interval is 150k same with valve adjust.

I also understand being able to easily work on my engine compared to others.

Sorry, when I say "newer" diesels I mean the CP4 diesels, don't know much about Cummins. The official coolant interval per Ford manual is 105K miles I think but people are doing it at 30-50K all in the hope that the engines will last what the old 7.3Ls did. It's become stupid at this point, over maintenance and all but apparently the consensus is that either they work all day every day or if you are a casual pavement princess or low-milage tower, then excess maintenance is in order.... what do I know....

For some unknown reason Cummins went from the CP3 to the CP4 in 2019 & 2020 and back to CP3 2021.

It's not an unknown reason - the reason is the excessive amount of CP4 failures.

[Cummins12V98]

ognend wrote:

Cummins12V98 wrote:
I was referring to my 15 RAM/CUMMINS. My coolant interval is 150k same with valve adjust.

I also understand being able to easily work on my engine compared to others.

Sorry, when I say "newer" diesels I mean the CP4 diesels, don't know much about Cummins. The official coolant interval per Ford manual is 105K miles I think but people are doing it at 30-50K all in the hope that the engines will last what the old 7.3Ls did. It's become stupid at this point, over maintenance and all but apparently the consensus is that either they work all day every day or if you are a casual pavement princess or low-milage tower, then excess maintenance is in order.... what do I know....

For some unknown reason Cummins went from the CP3 to the CP4 in 2019 & 2020 and back to CP3 2021.

[ognend]

Cummins12V98 wrote:
I was referring to my 15 RAM/CUMMINS. My coolant interval is 150k same with valve adjust.

I also understand being able to easily work on my engine compared to others.

Sorry, when I say "newer" diesels I mean the CP4 diesels, don't know much about Cummins. The official coolant interval per Ford manual is 105K miles I think but people are doing it at 30-50K all in the hope that the engines will last what the old 7.3Ls did. It's become stupid at this point, over maintenance and all but apparently the consensus is that either they work all day every day or if you are a casual pavement princess or low-milage tower, then excess maintenance is in order.... what do I know....

[Cummins12V98]

I was referring to my 15 RAM/CUMMINS. My coolant interval is 150k same with valve adjust.

I also understand being able to easily work on my engine compared to others.

[ognend]

Cummins12V98 wrote:
"The new diesels are complex beasts that require crazy maintenance and are prone to pump, turbo, emissions etc."

Not sure what you mean by "crazy maintenance" ???

I change my oil and two fuel filters @ 15k. Air filter schedule is 20k, I just do mine at 15k also. Not sure that should be considered "crazy maintenance".

If you go onto any Facebook Powerstroke 6.7 group or to any powerstroke forum or look up many "reputable" powerstroke service people's videos - they all recommend oil changes every 5K miles and then all fuel filters every 10K miles. If you are not doing this yourself, it will cost you roughly $150 per oil change and $350 per both oil/fuel filters service. Then there is the recommendation to use a lubricating additive to keep the CP4 from exploding (with every full tank). Many people also drain/refill their coollant every 30-50K miles for good measure. It has become nuts out there on these recommendations. A lot of people are installing CP4 disaster prevention kits like the S&S or the SPE even when there is no proof they actually work. So on and so on.

Every time someone comes on to complain about something regarding any of these new diesels, they are always waved off as "improper maintenance". Should have done this more, should have done that more frequently. Don't use Rotella, use Amsoil, use hot-shot additive, the list goes on and on.

There are plenty of "testimonies" online of Ford denying warranties on the CP4 pumps, blaming contaminated fuel. Apparently Americans can't make a good high pressure fuel pump and they are using the German made Bosch - which is made for clean European diesel. Apparently here in the States we cannot guarantee that the ULSD will be clean, always.

Overall, the new diesels operate within very tight tolerances and are super touchy and sensitive with many more parts that fail, some of which fail spectacularly (like the CP4 pump which destroys the whole fuel system and can cost up to $12K to fix). I believe there are lawsuits out there right now concerning Ford and the pump (https://www.prnewswire.com/news-releases/hilliard-martinez-gonzales-llp-federal-judge-rejects-ford-m...). If you think you are safe for not owning a Ford, the same pump is in every other new diesel, I think.
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Or you could just get a gasser 😉 - if you are towing infrequently or weights that are not excessive. None of the emission or HPFP drama, none of the turbo failing stuff, no super expensive oil/fuel filter changes, engine is simple, you can see the ground through the engine bay. I seriously feel pity for the mechanics who work on the 6.7Ls - how do you even get access to a lot of the stuff....?

[Grit_dog]

Yeah now that I have a “15,000mile” interval Ram and stepped up from Dino juice to syn on the new truck, I will be doing roughly only 40% of the number of oil changes that I do on all the gassers.
Will see if I can let myself go 15k though, lol. I just changed at 10k last weekend, but idk what was in it or oil from the previous owner. It had fresh oil change and fuel filters when I bought it.
One observation, front filter at 10k miles was cleaner than expected. I wouldn’t hesitate to go 15k on fuel filter. Front one at least. Didn’t cut open the back one.

[Grit_dog]

^Old wives tale from the Ford HPOP days.
Those injection pumps hated old oil and loved fresh oil.

[Cummins12V98]

"The new diesels are complex beasts that require crazy maintenance and are prone to pump, turbo, emissions etc."

Not sure what you mean by "crazy maintenance" ???

I change my oil and two fuel filters @ 15k. Air filter schedule is 20k, I just do mine at 15k also. Not sure that should be considered "crazy maintenance".

[frankwp]

4x4ord wrote:

Cummins12V98 wrote:
" I'm "getting by" with a GM 8.1 pulling a 12,000+ fifth wheel & see no need for anything more. I tow from Calgary to Radium, BC through the Rockies at least twice a year. there are sections with 8% grade & I can maintain the speed limit even on those steep grades."

NOT calling you a liar but over 20,000# up 8% grade at the speed limit I would assume around 60mph is honestly hard to believe.

Maybe 4x4ord can chime in on this.

You’re right Ron, a 20k lbs truck and rv doesn’t go up an 8% slope at 60 mph powered by a 340 hp engine. There is quite a climb coming out of Radium (this is probably the 8% grade being mentioned) but I think the speed limit might only be 90 km/hr. Even so, it takes roughly 100 hp to overcome the drag and rolling resistance of even a small 5ver at 90 km/hr. The rear wheel hp required for an 8k truck to overcome gravity while pulling a 12k trailer up an 8% grade is exactly 234.66 hp. So 335 hp is very close to the required power at the rear wheels. The 8.1 litre GM made as much as 340 peak crankshaft hp at 4200 rpm at sea level. So, maybe 260 hp rear wheel hp at 3000 ft elevation. So if the 8.1 litre had a gear to utilize 100% of hp it could pull that hill at about 42 mph.

Oops, busted! Thanks for the reality check guys. That stretch out of Radium has lots of curves, which are 60 K/hr & the rest is 80 K/hr. Going up that stretch I generally don't have a problem keeping with the speed limit, I just was forgetting the the limit was that low. BTW, the combined weight of truck & fifth wheel is just a bit over 19,000 lbs

My main point was that something like the 7.3 Ford gasser should be quite capable.

[ognend]

The new 6.6L chevy gasser or the 7.3L ford gasser are both potent towers. I would say anything up to 16,000 lbs and 3500-4000 hitch weight is OK to tow with these trucks. The new diesels are complex beasts that require crazy maintenance and are prone to pump, turbo, emissions etc. failures where you will either have to maintain an expensive warranty (extended) or eat up the cost - a CP4 failure on the new powerstrokes can easily cost you up to 12K to repair and ford has frequently denied these claims blaming bad fuel for the issues (it is the Bosch CP4 pump that has a problem so....).

An F-350 SRW gasser or a 3500 Chevy SRW gasser should have payloads in the 3700-4000 lbs and plenty of towing capacity.

At current gas and diesel prices assuming you tow about a 1,000 miles per month, you are looking at 80,000 miles to make up the $10K premium you pay for a diesel engine. Add to that the fact that most powerstroke people tell you to do oil changes every 5K miles ($150 at the dealer) and oil+fuel filters every 10K miles ($350 at the dealer), you are looking at extra $4,000 in maintenance over the course of the above-mentioned 80,000 miles. Did I mention lubrication additives with each diesel fuel-up? Boy, you think you are pampering a machine made out of gold! Anyway, this realistically means you will take 100,000 miles or 10 years to make up the diesel engine premium! And there are no risks of CP4, turbo, emissions etc. failures, no mystery coolant leaks...

IMHO, only people towing > 16,000 lbs and people who work out of a truck (tow things daily like tractors, heavy equipment etc. to work sites) need a diesel. The whole myth of the "reliable and runs forever diesel" was built on the pre-2004 7.3L powerstroke and pre 2004 12/24v 5.9L Cummins engines - they were easy and cheap to maintain (but then they had the same torque output as the new 7.3L ford and 6.6L chevy gassers so you weren't getting anywhere in a hurry). Today's diesel engines put out 450+ HP and 1000 ft/lbs torque and are SUPER complicated. Just open the 6.7L engine bay and then open the 7.3L gasser engine bay. You could drop a screw driver in the former and never find it again...

[4x4ord]

Grit dog wrote:

mkirsch wrote:


What's the difference? Don't know. Ford won't tell anyone.

All we know is that it is rated for 7230lbs and the others are not.

What makes the AXLE unsuitable? Probably nothing. Most of these axles from their respective component manufacturers are rated to 10,000lbs gross.

However, as you well know, there is more than just an axle at play here. Springs. Frame. Tires. There may or may not be differences there. Don't know. Ford still isn't talking. All we know is that they're willing to extend the warranty for 7230 if you buy the 7230 axle.

Yes, I get your "Just shove a chunk of well casing between the axle and frame, and load 'er down, it's all good!" attitude. I'd agree with you if the OP was looking at anything besides a brand new truck. When you can get the truck from the factory built for the job, why would you buy a lesser truck and immediately start putting aftermarket load assistance devices on it?

You can figure out the difference. You just have to spend a little time figuring it out. You're correct though, it is not in the axle.
But they still offer srw trucks with 17" wheels and we all know you can't buy a normal 17" tire with more than a 3200lb load rating.

My attitude is exactly opposite of what you said though (although, I'll admit to doing similar things, maybe, more than once, lol).
It is one of education and my attempt to dispell the plethora of Rvnet myths and misnomers and old "I remember when" logic.
Cheers bud!

According to Ford: “Gross Axle Weight Rating is determined by the rated capacity of the minimum component of the axle system (axle, computer-selected springs, wheels, tires) of a specific vehicle. Front and rear GAWRs will, in all cases, sum to a number equal to or greater than the GVWR for the particular vehicle. Maximum loaded vehicle (including passengers, equipment and payload) cannot exceed the GVW rating or GAWR (front or rear).”

In reality I don’t think the rated capacity of the axle is ever the minimum component of the axle system. Additionally there are times when the minimum component is simply the door sticker.

[Grit_dog]

mkirsch wrote:


What's the difference? Don't know. Ford won't tell anyone.

All we know is that it is rated for 7230lbs and the others are not.

What makes the AXLE unsuitable? Probably nothing. Most of these axles from their respective component manufacturers are rated to 10,000lbs gross.

However, as you well know, there is more than just an axle at play here. Springs. Frame. Tires. There may or may not be differences there. Don't know. Ford still isn't talking. All we know is that they're willing to extend the warranty for 7230 if you buy the 7230 axle.

Yes, I get your "Just shove a chunk of well casing between the axle and frame, and load 'er down, it's all good!" attitude. I'd agree with you if the OP was looking at anything besides a brand new truck. When you can get the truck from the factory built for the job, why would you buy a lesser truck and immediately start putting aftermarket load assistance devices on it?

You can figure out the difference. You just have to spend a little time figuring it out. You're correct though, it is not in the axle.
But they still offer srw trucks with 17" wheels and we all know you can't buy a normal 17" tire with more than a 3200lb load rating.

My attitude is exactly opposite of what you said though (although, I'll admit to doing similar things, maybe, more than once, lol).
It is one of education and my attempt to dispell the plethora of Rvnet myths and misnomers and old "I remember when" logic.
Cheers bud!