Ford F550 and the 7.3

Porkchopexpress

Well-known member
That seems odd to me, too. If anything, I’d have thought it’d be the other way around.
Most people who buy the F450 pickup truck use it for towing. I think the diesel is far superior to the 7.3 gas towing heavy loads. Chassis cabs are usually fitted with heavy tool boxes or other industrial equipment so heavy loads without towing are more likely.
 

skrypj

Well-known member
I agree that it will probably be derated, but that’s nothing that a tune can’t fix. The 7.3 is easily tuneable. As for mileage, yeah we are all just speculating at this point. The 7.3 is pretty efficient for a big block v8 but how bad could it be? Like 7 or 8 mpg?


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It is not actually derated. The difference is in how they test and rate the truck with certain GVWR. The F450/550 are rated by a different standard than the 250/350

I read an article in the differences and wish I could remember where it was.

Edit: now that i am thinking about it, it was actually ford that explained the difference and why they have different ratings. They basically said the tuning wasn’t different, its the testing method that was different.

I feel like it was an article on TFLTruck. They were test driving a ford RV chassis(without the body) with the 7.3L
 

skrypj

Well-known member
It is not actually derated. The difference is in how they test and rate the truck with certain GVWR. The F450/550 are rated by a different standard than the 250/350

I read an article in the differences and wish I could remember where it was.

Edit: now that i am thinking about it, it was actually ford that explained the difference and why they have different ratings. They basically said the tuning wasn’t different, its the testing method that was different.

I feel like it was an article on TFLTruck. They were test driving a ford RV chassis(without the body) with the 7.3L

Found it:

14ac891ae6401d5e71722bde3ab3961f.jpg


Ignore what I said above.
 
Last edited:

cobro92

Active member
Most people who buy the F450 pickup truck use it for towing. I think the diesel is far superior to the 7.3 gas towing heavy loads. Chassis cabs are usually fitted with heavy tool boxes or other industrial equipment so heavy loads without towing are more likely.

Yeah I would assume the 7.3 would have plenty of power for a large payload. Towing is a different animal.


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1000arms

Well-known member
Yeah I would assume the 7.3 would have plenty of power for a large payload. Towing is a different animal.
2021 F-350 4x4 DRW RCLB pickup with 7.3L gas engine and 4.30 gears, maximum conventional towing (bumper) is 20,000 pounds. 28,000 GCWR.

2021 F-450 4x4 RC chassis truck with 7.3L gas engine and 4.88 gears, maximum conventional towing (bumper) is 17,500 pounds. 28,000 GCWR.

2021 F-550 4x4 RC chassis truck with 7.3L gas engine and 4.88 gears, maximum conventional towing (bumper) is 18,500 pounds. 28,000 GCWR.

The towing capacity for the 7.3L gas engine is pretty good, but, for heavy payload combined with heavy towing, the 6.7L diesel engine would be a good choice with the much greater GCWR.

The chassis trucks listed above have the same maximum conventional towing (bumper) with the 6.7L diesel engine. To tow more with the diesel, one would need to go to 5th-wheel/gooseneck.
 

Porkchopexpress

Well-known member
2021 F-350 4x4 DRW RCLB pickup with 7.3L gas engine and 4.30 gears, maximum conventional towing (bumper) is 20,000 pounds. 28,000 GCWR.

2021 F-450 4x4 RC chassis truck with 7.3L gas engine and 4.88 gears, maximum conventional towing (bumper) is 17,500 pounds. 28,000 GCWR.

2021 F-550 4x4 RC chassis truck with 7.3L gas engine and 4.88 gears, maximum conventional towing (bumper) is 18,500 pounds. 28,000 GCWR.

The towing capacity for the 7.3L gas engine is pretty good, but, for heavy payload combined with heavy towing, the 6.7L diesel engine would be a good choice with the much greater GCWR.

The chassis trucks listed above have the same maximum conventional towing (bumper) with the 6.7L diesel engine. To tow more with the diesel, one would need to go to 5th-wheel/gooseneck.
If you watch YouTube videos of TFL Truck testing on Ike Gauntlet, the gas vs diesel performance towing up hill is night and day difference. I'm buying the 7.3 because it will satisfy my requirements, (slide in camper and occasional towing), but I would have sprung for diesel if I planned on towing heavy loads regularly.
 

nickw

Adventurer
Not too long ago guys were driving around those medium duty Ford dump trucks with V8's gas motors and were doing fine with ~200 hp....I have no worries the 7.3 will work in the smaller platform without issue and have good performance after driving a F250 with the 7.3. I think we've all grown accustomed to big HP and Torque and have a level of expectation that is rarely met....but getting from point A to B, keeping up with traffic with a good service schedule....the basic stuff, the 7.3 is going to do great.

My old Tacoma had 190 HP, my new Ranger is closer to 300, I can't imagine how the hell I did it....but I did just fine....
 

1000arms

Well-known member
2021 F-350 4x4 DRW RCLB pickup with 7.3L gas engine and 4.30 gears, maximum conventional towing (bumper) is 20,000 pounds. 28,000 GCWR.

2021 F-450 4x4 RC chassis truck with 7.3L gas engine and 4.88 gears, maximum conventional towing (bumper) is 17,500 pounds. 28,000 GCWR.

2021 F-550 4x4 RC chassis truck with 7.3L gas engine and 4.88 gears, maximum conventional towing (bumper) is 18,500 pounds. 28,000 GCWR.

The towing capacity for the 7.3L gas engine is pretty good, but, for heavy payload combined with heavy towing, the 6.7L diesel engine would be a good choice with the much greater GCWR.

The chassis trucks listed above have the same maximum conventional towing (bumper) with the 6.7L diesel engine. To tow more with the diesel, one would need to go to 5th-wheel/gooseneck.
If you watch YouTube videos of TFL Truck testing on Ike Gauntlet, the gas vs diesel performance towing up hill is night and day difference. I'm buying the 7.3 because it will satisfy my requirements, (slide in camper and occasional towing), but I would have sprung for diesel if I planned on towing heavy loads regularly.
I don't need to watch the videos you referenced to know there is a big difference between the 7.3L gas engine and the 6.7L diesel engine. :)

I posted the 2021 F-350/F-450/F-550 information because I think some people might find the 7.3L gas engine meets their requirements. :cool:
 

Trixxx

Well-known member
Yes I agree that the mileage will be absolutely garbage on an F550 with the gas motor. But how much better would the diesel be? Maybe 5mpg?


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8 vs 13 mpg is a pretty big difference on a long trip.
I have the 6.7. Couldn’t be more pleased. A 7.3 would work fine for me but I wanted the power and range when towing.

The 7.3 seems to be a good motor from the many 2020 super duty groups I’m in. Rarely are owners not pleased as long as they curb their expectations in regards to mileage and torque.
 
Just an anecdote. 2021 350 Tremor 7.3 with 1800lbs camper on the back. Averaging 13mpg in mountaineous up and down terrain at 65pmh. Averaging 16mpg when I take the camper off. Not horrible, but definitely burning through that puny 30 gallon tank rather quickly...

That said, while the tranny has to downshift more than on my previous 3L Duramax Diesel with the same camper, I never lack for power or torque when I need to pass uphill even at 10'000ft elevation.
 

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