19.3 MPG on 2023 Max Limited, Will Additives Help?

[Phil1919]

19.3 seems about the best I can get, even after traveling down 75 miles of interstate.

Will Seafoam, Marvel Mystery Oil, or Lucas added to gas help? What the best/safest to use, and can it be used often?

I suspect the oil was not changed as often as I would do it, as it was a Hertz vehicle.

Already did the fuel system treatment at a Ford dealer but that did nothing to help.

 

[DieselMonk]

Sounds about right for winter driving at if I compare it to mine non Max SPP with a 3.73 rear end.
I get about 11.8L per 100km, comparing to your 12.2L per 100km. But I am at sea level. Regular or Supreme didn’t matter on mine during winter driving.
I doubt seafoam or any additive will do anything to that engine, since it has port injection and direct injection (2 injectors per cylinder).
Only thing you can try is to fill up with supreme and the drive it like you stole it for a tank full, then do the test again.
Forgot: wind and driving above 65mph affects fuel mileage a lot!

 

[2018ExpyPlatinum]

Not to be a jerk, but you know it's a 6000 pound brick, right? You don't buy an Expedition for gas mileage. Mostly around town I'm 16-17. On the highway, I'm about 21-22. Best I ever got was when we moved out west. I was driving the rental truck and my wife followed me in the Expy. Top speed of the rental was 65 and she was getting about 24-25.

High speed will kill the gas mileage, as will getting into the turbo. Premium might help, but it's really hard to say, although it will run better.

 

[JD34]

So these is my results..( yours may vary) 22 Ex.Max.limited, 43500 Miles, 21.5-22.9 mpg Highway, try for 10-mph over speed limit, usually travel pa/philly area to fl-keys.. 1350 mi one way.. I have found premium fuel gives me another 1.5 avg mpg over reg. fuel, tire pressure 5# over pressure stated on tire/or door sticker.
(remember sometimes different manufacturers have different ratings than OE tires) I also recently added a K&N cold air intake #30-2617. I am happy with the results,knowing the size of the vehicle and my speeds, I'm usually over 70 mph most of the time..
Have played with Reg. & Sport modes.. Reg. mode usually a little better, depends on the terrain & traffic.. Sport mode downshifts a lot, but if it's flat Sport does well.
And I always use a Top Quality pure synthetic oil with one qt Lucas Synthetic Oil Stabilizer..

 

[Paddler]

Guessing my long term average at 21-22MPG over 81K miles. On a trip to California I averaged 24.2MPG at 68MPH plus some city driving.

I don't use additives of any kind because they don't work and so are a waste of money, ie, they're snake oil.

 

[LokiWolf]

Additives regularly are somewhat a waste. Everynow and then for the cleaning factor, maybe. Ethanol in modern fuel does a pretty good job maintaining the cleaning aspect.

You missed a few details. One important one. How many miles?

Also, change the plugs.

 

[duneslider]

You also didn't mention speed. If I am cruising at 85 the mpg is not super great compared to cruising at 70.

 

[GixxerJasen]

4WD? Heavy Tow Package? What wheels and tires? What's your normal driving like? Need details, because you might be right on target, if not a little high. So many variables.

When i changed tires, the diameter only went up a tiny bit, got skinnier and the overall tire/wheel weight went down, so theoretically I should be getting better mileage, but that aggressive A/T tread means it went down a little bit.

Big difference also between when I lived in Cleveland with a lot of low speed roads with a ton of stop lights and stop signs, vs living in Dallas where you take a freeway to get anywhere.

 

[GlennSullivan]

I have a 2017 Gen 3 and just made the NY to Jupiter FL trip (1300mi). Truck is standard length, 4WD, HD Tow, 3:31 Axle.

In recent years I've run this route with this truck in October and May and gotten 20-21 mpg running at 70-75 mph and 19-20 at 75-85 mph.

This year we were delayed and just ran the route last week. The only difference was the ambient temperatures. I found with the colder temps which included remote starting the truck for a warm up, that our 70-75 mpg dropped to 19.5 and 75-85 18.5. I would have thought that the AC running less for 3/4 of the trip would have offset the remote start warmup, but not so. Colder temps = less fuel economy.

 

[Paddler]

I have a 2017 Gen 3 and just made the NY to Jupiter FL trip (1300mi). Truck is standard length, 4WD, HD Tow, 3:31 Axle.

In recent years I've run this route with this truck in October and May and gotten 20-21 mpg running at 70-75 mph and 19-20 at 75-85 mph.

This year we were delayed and just ran the route last week. The only difference was the ambient temperatures. I found with the colder temps which included remote starting the truck for a warm up, that our 70-75 mpg dropped to 19.5 and 75-85 18.5. I would have thought that the AC running less for 3/4 of the trip would have offset the remote start warmup, but not so. Colder temps = less fuel economy.

My Gen 3 got much worse mileage than yours. I very much doubt 19-20 MPG at 75-85MPG, which would be an average 0f 80MPH. I'd have to see that to believe it. The Ecoboost with the 10-speed is much more fuel efficient than the old 5.4 with the 6-speed IME.

Drag, and thus energy required to push a car, is related to the velocity squared. Increasing your speed from an average of 72.5MPH, at which you say you get 20-21MPG, to and average of 80MPH, is a 10% increase, which would require 21% more energy, which should decrease your mileage by 21%. Best case, which would be 20.5 MPG at 72.5MPG, which I never saw, BTW, you should get 16.2MPG at 80MPG.

 

[LokiWolf]

My Gen 3 got much worse mileage than yours. I very much doubt 19-20 MPG at 75-85MPG, which would be an average 0f 80MPH. I'd have to see that to believe it. The Ecoboost is much more fuel efficient than the old 5.4 IME.

His 2017 is an EcoBoost. 15-17 in Gen3 were EcoBoost.

 

[Calidad]

I wouldn’t put any additives into a complex and expensive fuel system. Not to mention it won’t do anything.

19mpg sounds about right but conditions, temperatures, speed, idling time all play a role. Of which you haven’t really given any info on those factors.

 

[Deadman]

Slow down. Mine will make 25mpg at 58mph. At 85 it makes 17-18mpg.

 

[SyndicateZ]

I get about 19 on the highway at 65mph.

 

[Paddler]

I get about 19 on the highway at 65mph.

That sounds low. I get 23-24+ on CC at 63MPH in Normal mode. Probably would get a bit more in ECO mode. Coming back from northern California to SLC with a tailwind I got 28MPG at 68MPH, calculated.

Running Michelin Defender LTX m/s at 42PSI.

 

[GlennSullivan]

My Gen 3 got much worse mileage than yours. I very much doubt 19-20 MPG at 75-85MPG, which would be an average 0f 80MPH. I'd have to see that to believe it. The Ecoboost with the 10-speed is much more fuel efficient than the old 5.4 with the 6-speed IME.

Drag, and thus energy required to push a car, is related to the velocity squared. Increasing your speed from an average of 72.5MPH, at which you say you get 20-21MPG, to and average of 80MPH, is a 10% increase, which would require 21% more energy, which should decrease your mileage by 21%. Best case, which would be 20.5 MPG at 72.5MPG, which I never saw, BTW, you should get 16.2MPG at 80MPG.

The 2017 is 3.5 TT EcoBoost and those are the mpg Ive been getting on road trips for years. My 2011 with the 5.4 3 valve is more in line with your estimates above.

 

[SyndicateZ]

That sounds low. I get 23-24+ on CC at 63MPH in Normal mode. Probably would get a bit more in ECO mode. Coming back from northern California to SLC with a tailwind I got 28MPG at 68MPH, calculated.

Running Michelin Defender LTX m/s at 42PSI.

Indeed

 

[Paddler]

2017 is 3 5 TT ecoboost and those are the mpg Ive been getting on road trips for years. My 2011 with the 5 4 3 valve is more in line with your estimates above.

Sorry, Glenn, my mistake. I thought the Triton 5.4 was in all Gen 3s. I had a Gen 1 (1998), a Gen 3 (2008, bought used in 2010). I drove my Gen 3 for 100K miles. I read about the Gen 4 in 2018, and happened to stop by a dealer to check it out shortly thereafter. Ended up ordering one that day despite having no intention to do so because of the aluminum body, 10-speed trans and Ecoboost Gen 2.

 

[GixxerJasen]

His 2017 is an EcoBoost. 15-17 in Gen3 were EcoBoost.

Is that why we get a lot of Gen3 guys cross posting into the Gen4 section? Always wondered that.

 

[GlennSullivan]

Is that why we get a lot of Gen3 guys cross posting into the Gen4 section? Always wondered that.

Something like that. I have a 2011 and a 2017 which I refer to as a Gen3A (2010-2014) and Gen3B (2015-2017) because they are such different vehicles. The Gen 3B has some of the features (and issues) as Gen 4.