7.3 gas engine vs Powerboost

[Rabbit Hash]

I’m going to be his twin, except the engine ha! From my understanding the 3.5 would be perfect but being an old hot rodder, I just can’t help myself on the V8. Even if it doesn’t make sense! Ha!!

He helped me so much on the Escape RV forums with the setup, hitch, and other things. A lot of gratitude!! ?

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[Snakebitten]

That Coyote is going to sing just fine pulling that unicorn 5th.

I'm a long time RV'r, as well as a full timer. I'm typing this from an RV on the Texas Gulf Coast beach, in fact. I've never understood why there are so few lightweight 5vers built. A halfton truck would pull like a dream with smaller lighter 5ths. I suspect the geometry makes it tough to keep the pinweight low enough for the 1500# Payload of the platform?

 

[Rabbit Hash]

Thank you SnakeBitten! I think you hit the nail on the head on pin weight. These campers are 650# pin because they are molded fiberglass shells and not stick built so the weight is down. I think 99% of folks including everyone I know prefer more room and a slide out. So like you said, this is a unicorn. The wife seems to be on board so hopefully we don’t upsize. Enjoy your travels! I’m jealous but we are almost there (retirement)!

 

[Suns_PSD]

I recently was helping a friend look for a new 3/4-ton truck to tow with. Both my Ford and RAM salesman recommended going with gas engines and avoiding the diesel. They said that the EPA has constrained diesel engines so much you would be in the regen cycle too often unless you would be towing a heavy load the majority of time that the truck was being driven. I have no experience with this but was surprised that both dealers made this recommendation.

I sell semi-trucks and specialize in vocational trucks, things like dump trucks.

Most of my dump trucks I build to be lightweight to maximize the legal payload, and they use an 8.9-liter Cummins engine with about 360 hp/ 1150tq and when loaded the trucks weigh 62,500#s. Commercial engines are always tuned down for longevity and have redlines at only 2100 rpm. They pull the load quite well, like surprisingly well. But then most truckers understand the liability that comes with going fast and therefore are okay with moderate speeds. These motors last > 550K miles, in mostly inner city, stop and go duty cycle. I see few emissions issues. Maybe each truck might average one single emissions system repair in its lifetime, an EGR valve or a bad def injector or the like. When you understand the amount of fuel going through these engines, it's not a big deal.

However, I have some clients that are less concerned with payload or cost and get a 15 liter 565 hp Cummins instead. They always see more emissions system issues and the motors really don't last any longer. They do a lot more regens where the engine has to inject diesel fuel to burn off accumulated soot in the DPF. The small motors have to work; therefore they generate heat, and they keep the emissions system much cleaner ime.

Now scale that to a HO Powerstroke pickup truck that has 500hp/ 1250 tq yet spends 95% of its miles picking up groceries and the kids from school. That emissions system really struggles to get hot and clear out.

I get that lots of people have lots of money and just want the baddest thing out there, but if you aren't towing > 50% of your miles, these modern diesels just are a bad idea.

 

[Suns_PSD]

I love my PB as a daily, but it gets horrible mileage towing. I just towed a U-Haul Car hauler trailer with a super light Polaris Rzr on it...Orange County to Santa Barbara (relatively flat) and got 12.5mpg. If I was towing regularly I'd be in a diesel hands down. My old 7.3 Excursion would barely flinch when a trailer was hooked up. Diesel diesel diesel (if towing regularly)

I borrowed a tandem axle MiniLite RV that has a listed weight as 5K (probably 6K as loaded) this past weekend to give it a try. I drove very moderately (63-65 mph) on the way up with the top 2 gears locked out and averaged 9.6 mpg. I -35 is slightly rolling in this area.

On the way back, the WDH was doing its thing and the trailer pulled just lovely, and I averaged closer to 65-68 mph and I averaged 7.2 mpg.

Whoof! This was a short trip of 100 miles each way, but I don't want to head out long distances getting 7 mpg. That's just not acceptable. Heck, just the extra fuel used pays for a hotel room instead!

It was a good experiment, and it solidified what I want in an RV. It must be collapsible to better align with my camper shell for aero, as small as I can live with and very capable of being off-grid. And the black tanks are disgusting; I'd only own a cassette toilet.

 

[v8440]

You're supposed to stay out of the tanks; just saying.

 

[Samson16]

Thank you SnakeBitten! I think you hit the nail on the head on pin weight. These campers are 650# pin because they are molded fiberglass shells and not stick built so the weight is down. I think 99% of folks including everyone I know prefer more room and a slide out. So like you said, this is a unicorn. The wife seems to be on board so hopefully we don’t upsize. Enjoy your travels! I’m jealous but we are almost there (retirement)!

Oh he isn’t retired. He’s just on the beach ?

 

[Saturnfire]

By next year this could be a very attractive option depending on how much of the tailpipe emission equipment is deleted by the new EPA actions. But you need a hybrid to get 7.2 kW of PPoB, something I consider to be required when pulling an RV trailer these days.

I was getting excited about possibility of a SuperDuty hybrid coming out next year until I just learned the plant that was tooled to make that truck is in Canada. Not going to happen now.

I would be in an F350 6.7 HO w/o Commie envirocrap stuff all over it, if it was made legal.

 

[Snakebitten]

Oh he isn’t retired. He’s just on the beach ?

You know me way too well.
Ain't retired indeed.
I fear it's getting close, but if they'll put up with my shenanigans, I will keep collecting the discretionary income and frivolously fund my grandchildrens adventures!

Cuz once the corporate tap gets turned off, Pawpaw is going to have to downshift considerably. ???
In fact, staying at Best Western IS in fact less expensive than FREE camping on the beach with an RV. But it's nowhere near as appealing.

 

[amschind]

I think that I misunderstood the question: Let me answer again.

1) For towing BIG/HEAVY stuff, the 7.3 SD is the correct answer. I'd buy a 3.5 PB mated to a 10R140 in a heartbeat, but Ford in its great wisdom has not yet seen fit to grace us with such a beast.

2) For a wife pleaser, get a late 1970s Airstream 25' trailer with the worst interior you can find, then pay too much to have it completely redone (make sure that you get Coosaboard subfloor replacement, but don't be afraid of "Subfloor separation" on the trailer you buy to get a deal since you're replacing the plywood anyway). Miller Garage in East DFW does an awesome job, though I think that he and his wife are moving around on continuing to do AS restorations. A PB will pull that like it's not there.

I hope that's more useful.

 

[JExpedition07]

I think a lot of people are confused on the PowerBoosts capabilities. The 7.3 up a 7% grade is 430 HP indefinitely. The PowerBoost drops out to 400 HP in the matter of a minute under that constant load, and then will further drop in power the more the turbochargers heat soak and it pulls back ignition timing. 10 minutes into a climb in 85-90 degree ambient it will look more like

7.3: 430 HP
3.5 PB: 380 HP

Now the big ass 6.7 PS I ordered shouldn’t have such heat soak problems as it’s cast iron with huge bores and gigantic radiator to shed the heat. The 3.5 EB just does not have the raw size to be 3/4 ton worthy. It can’t soak up that heat/shed it or really brake well. No real reason to ever throw a 10R140 behind it, the 7.3 does just about everything better than the 3.5.

My only gripe with the 7.3 was the empty feel was lacking a bit compared to the diesel and half ton offerings. But I’m sure it’s a beast that doesn’t give in when working it.

 

[JCsTruck]

I think a lot of people are confused on the PowerBoosts capabilities. The 7.3 up a 7% grade is 430 HP indefinitely. The PowerBoost drops out to 400 HP in the matter of a minute under that constant load, and then will further drop in power the more the turbochargers heat soak and it pulls back ignition timing. 10 minutes into a climb in 85-90 degree ambient it will look more like

7.3: 430 HP
3.5 PB: 380 HP

Now the big ass 6.7 PS I ordered shouldn’t have such heat soak problems as it’s cast iron with huge bores and gigantic radiator to shed the heat. The 3.5 EB just does not have the raw size to be 3/4 ton worthy. It can’t soak up that heat/shed it or really brake well. No real reason to ever throw a 10R140 behind it, the 7.3 does just about everything better than the 3.5.

My only gripe with the 7.3 was the empty feel was lacking a bit compared to the diesel and half ton offerings. But I’m sure it’s a beast that doesn’t give in when working it.

Best explanation I have heard yet! ?

 

[Chris GTO TT]

I think you're over estimating heat soak losses on the power boost and drastically underestimating the elevation losses on an NA engine. If your 7% grade starts at 5000ft and climbs to 7000ft or more the 7.3 is only making at most 365hp. This is assuming we use the 3% loss per 1000ft elevation rule. In most cases the 3.5 EB or PB will pull harder than the 7.3. The numbers say so.

The 7.3 should however be more durable over the long run pulling the same weights, and the SD will do a far superior job of controlling the weight, sway, and cross winds. The main reason I want a 7.3 SD is for the cross wind control because I swear the only times we tow the travel trailer is when there are 20+mph winds with gusts over 30 lol

 

[Aonarch]

I'd own a 7.3l Tremor if they had a shorter wheelbase.

The 7.3l is underrated power wise from the factory. They make low to mid 500s hp/tq.

Ford is all in on making the 7.3l a swap engine, and the aftermarket has a ton of performance goodies for them.

I'd way rather do a Whippled 7.3l than a DEF Powerstroke. Obviously fuel economy will be lower, but I'd reckon, TCO would be less after maintenance, DEF, fuel, etc.

 

[JExpedition07]

Oh Ford could absolutely give the 7.3 a slight compression bump and semi-serious intake valves and it would be a nightmare for the competition. The performance crate version of the 7.3 Ford sells all ready makes 670 lb ft of torque naturally aspirated. The heads on the stock units are very restrictive to keep it out of diesel market share territory methinks.

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