7.3 twin turbo Godzilla

Bionic Man wrote:

ShinerBock wrote:
I had a work truck 5.0L and later a work truck Ecoboost and they both got the same crappy fuel mileage towing the same exact same trailer. My personal F150 got no different fuel economy than a good friend mine 5.7L Hemi towing roughly the same load (Jeep and gear) down the same roads from Texas to Utah. The only difference was that his engine was huffing and puffing a little more the higher we went while I hardly felt any difference in power.

In my experience, turbocharged gassers get the same horrible fuel mileage when towing as a larger displacement engine with comparable power. More air equals more fuel and a turbocharger increases the amount of air being pushed through the engine just like increasing an engine's displacement does. The only difference is that you can go back to a smaller displacement when you don't need all that air(boost) in a turbocharged vehicle, but can't with a N/A engine of a larger displacment unless it has cylinder dectivatiuon.

I’ll just tell you point blank that hasn’t been my experience. While towing my wake boat, my EcoBoost Expedition gets at least 20% worse MPG than the Yukon 6.2 it replaced. It’s considerably worse when you compare it towing my 17’ fishing boat. Just about everyone on the boating forums I frequent say the same thing.

I’ll also say that the towing experience as well as speed over the passes is better in the EcoBoost than the 6.2. It holds speeds up the passes that the 6.2 simply couldn’t do.

I’m pretty comfortable saying a EcoBoost type engine gets slightly better MPG when solo and quite a bit worse MPG when towing. Which overall is a win in a vehicle that doesn’t tow frequently. But that isn’t what a 7.3 is designed for. It’s designed to be a work truck and if Ford added turbos it would suck fuel like a drunken sailor. The loaded MPG in a vehicle that is designed to spend a lot of time loaded would just make it highly impractical.

And FWIW, for my use in a full size SUV, I’d choose the EcoBoost over a 5.7 or 6.2. Just no way I’d consider it (or especially a super sized version of it) for a full time towing vehicle.

When Pickuptucks.com tested the Ecoboost versus the GM 6.2L, 5.7L Hemi, and Nissan 5.6L back in 2018, the Ecoboost got the best towing mileage and unloaded mileage. However, the 6.2L did get better fuel economy than the other two 5.xL engines when towing. I have read multiple reviews ad MPG loops the 6.2L even got better fuel economy than the smaller 5.3L when towing as well. I am not sure if it is the premium fuel requirement, but many tests I have seen showed the 3.5L Ecoboost and GM 6.2L neck and neck with each other on fuel economy when towing and both are generally better than the rest of the engines.


2018 Best Half-Ton Truck Challenge

I get the same mpg as Wing Zealot. I frequently get 21-22 on the highway doing 70 mpg (speed limit in WI) and 10.5 to 12 when towing my 3500 pound TT at 65 mph. If I slow to 55 mph, I can get 12 to 13.
I love the EcoBoost in the mountains where I don't have to worry about being at 9,000 to 11,000 ft. SAt those elevations, still have all of my horses and torque. I can go over the Beartooth or up the west side of the Bighorns on 14A and not worry about overheating or running out of guts. To keep my heat down I do downshift to let the tranny take a break. When I do that I am still under 3000 rpm's.

ShinerBock wrote:
I had a work truck 5.0L and later a work truck Ecoboost and they both got the same crappy fuel mileage towing the same exact same trailer. My personal F150 got no different fuel economy than a good friend mine 5.7L Hemi towing roughly the same load (Jeep and gear) down the same roads from Texas to Utah. The only difference was that his engine was huffing and puffing a little more the higher we went while I hardly felt any difference in power.

In my experience, turbocharged gassers get the same horrible fuel mileage when towing as a larger displacement engine with comparable power. More air equals more fuel and a turbocharger increases the amount of air being pushed through the engine just like increasing an engine's displacement does. The only difference is that you can go back to a smaller displacement when you don't need all that air(boost) in a turbocharged vehicle, but can't with a N/A engine of a larger displacment unless it has cylinder dectivatiuon.

I’ll just tell you point blank that hasn’t been my experience. While towing my wake boat, my EcoBoost Expedition gets at least 20% worse MPG than the Yukon 6.2 it replaced. It’s considerably worse when you compare it towing my 17’ fishing boat. Just about everyone on the boating forums I frequent say the same thing.

I’ll also say that the towing experience as well as speed over the passes is better in the EcoBoost than the 6.2. It holds speeds up the passes that the 6.2 simply couldn’t do.

I’m pretty comfortable saying a EcoBoost type engine gets slightly better MPG when solo and quite a bit worse MPG when towing. Which overall is a win in a vehicle that doesn’t tow frequently. But that isn’t what a 7.3 is designed for. It’s designed to be a work truck and if Ford added turbos it would suck fuel like a drunken sailor. The loaded MPG in a vehicle that is designed to spend a lot of time loaded would just make it highly impractical.

And FWIW, for my use in a full size SUV, I’d choose the EcoBoost over a 5.7 or 6.2. Just no way I’d consider it (or especially a super sized version of it) for a full time towing vehicle.

I had a work truck 5.0L and later a work truck Ecoboost and they both got the same crappy fuel mileage towing the same exact same trailer. My personal F150 got no different fuel economy than a good friend mine 5.7L Hemi towing roughly the same load (Jeep and gear) down the same roads from Texas to Utah. The only difference was that his engine was huffing and puffing a little more the higher we went while I hardly felt any difference in power.

In my experience, turbocharged gassers get the same horrible fuel mileage when towing as a larger displacement engine with comparable power. More air equals more fuel and a turbocharger increases the amount of air being pushed through the engine just like increasing an engine's displacement does. The only difference is that you can go back to a smaller displacement when you don't need all that air(boost) in a turbocharged vehicle, but can't with a N/A engine of a larger displacment unless it has cylinder dectivatiuon.

valhalla360 wrote:

Devo the dog wrote:
I'd put on a supercharger instead. Even though there is a parasitic loss, I'd prefer it over a turbo.

Superchargers are great for drag racing as they can negate turbo lag and get you off the line a hair quicker.

In a towing situation where time to spool up the turbo isn't an issue, it makes no sense to accept the parasitic loss...particularly for a manufacturer looking at govt fuel economy rules.

That's just your opinion. Furthermore,I said nothing about government, manufacture or fuel economy rules.

I stated that I would install a supercharger instead of a turbo. Let me put it another way: if I was going to pay money to modify my car or truck and was choosing between a turbo and a supercharger, I'd choose a supercharger.. It's my preference. It's less complicated.

BTW, turbos are used in drag racing and road racing.

GDS-3950BH wrote:

wing_zealot wrote:

The 20+ MPG Highway?
The 15 MPG City?
The 10.5 MPG Towing?
Do any of you have an Ecoboost?

I've put over 350K miles on 2 different F-150s since @ 2014/15. Both were 3.5 Ecoboost 4 door, short bed, 4x4. I call BS on those MPG numbers, not even close.

17.6 highway
13.4 city
Average everyday @ 15
Towing 14' utility trailer in VA/WV/NC/PA @ 7-8.

I have found that gas mileage with powerful engines depends a lot on how heavy your right foot is. You can drive an Ecoboost easy and get good fuel economy or you can drive it hard, turn a lot of fuel into heat and get lousy fuel economy. Always remember that speed requires exponentially more fuel and the Ecoboost makes speed easy.

On the other hand, my 3.5 Ecoboost gets about 20% better fuel economy than the V10 that it replaced and that is probably going faster than I did with the V10. Going fast with the Ecoboost is too easy for great fuel economy.

Devo the dog wrote:
I'd put on a supercharger instead. Even though there is a parasitic loss, I'd prefer it over a turbo.

Superchargers are great for drag racing as they can negate turbo lag and get you off the line a hair quicker.

In a towing situation where time to spool up the turbo isn't an issue, it makes no sense to accept the parasitic loss...particularly for a manufacturer looking at govt fuel economy rules.

wing_zealot wrote:

The 20+ MPG Highway?
The 15 MPG City?
The 10.5 MPG Towing?
Do any of you have an Ecoboost?

I've put over 350K miles on 2 different F-150s since @ 2014/15. Both were 3.5 Ecoboost 4 door, short bed, 4x4. I call BS on those MPG numbers, not even close.

17.6 highway
13.4 city
Average everyday @ 15
Towing 14' utility trailer in VA/WV/NC/PA @ 7-8.

noteven wrote:

4x4ord wrote:

Grit dog wrote:

ShinerBock wrote:
A large displacement turbocharged gas engine would need a HUGE cooling system to keep it cool in a towing application. Especially one that has a closed deck block like the 7.3L. The radiator would probably need to be the size of a medium-duty Peterbilt.

I'm sure 4x will be by shortly to refute it with some home-made bsfc to kilojoules of heat loss chart....LOL

I agree with 12V it’s gotta be a deezul if it’s going to tow. Maybe we gotta shrink the cooling system. 60% of our fuel’s energy is lost to heat either out the exhaust or into the cooling system. What if we could run some sort of super hot highly pressurized coolant through a nozzle that would spin a turbine coupled to a generator that could recapture that energy and feed it to electric motors at the wheels?

Cummins had an engine running on a dyno in their skunk works 30+ years ago testing some different materials concepts. It was complete with no "radiator waste" cooling system. Ceramic pistons, 2 or 3 staged turbochargers....I believe it had a condensing steam turbine system geared to the crankshaft.

I guess fuel is still too cheap to warrant messing around trying to get more power out of the same fuel. Just throw a couple turbos on and feed er a little more coal.

wing_zealot wrote:

Bionic Man wrote:

GDS-3950BH wrote:

rhagfo wrote:

Bionic Man wrote:
Speaking from first hand experience, with as poor of MPG as the EcoBoost gets towing, I can't imagine how bad this engine would suck fuel under load.

I would agree, likely can watch the fuel gauge move.

Was not much of an issue until the full out, no holds barred assault on the oil and gas industry. Bend over and grab em. We can't have folks wasting all this energy pulling around these RVs or anything else, it's the Green new deal. Just move to some inner city condo and shut up, we'll hand you everything you need, enjoy it.

When you can barely make 200 miles with a 30 gallon tank, MPG is an issue regardless of the price per gallon.

Which "poor" MPG are you referring to?
The 20+ MPG Highway?
The 15 MPG City?
The 10.5 MPG Towing?
Do any of you have an Ecoboost?

In 20,000 miles, the best MPG I’ve seen is 20.63 MPG. That was ONE time. Usually highway is 18 MPG. I have several tanks towing at 7-8 MPG with my 7000 pound boat. Towing my 17’ fishing boat yields that 10.5ish you’re referencing, and that is maybe 3200 pounds and not much air resistance.

Hardly stellar MPG numbers. Power is good. Non towing MPG is ok. Towing MPG is simply bad.