What kills mpg: Boost vs downshifting?

[BroncoPQ]

Outerbank NON sas + 33 tires on 2.7: doing 15l/100km or 15 mpg


Wonder what would be worse beside downshifting the 10 speeds automatic vs increase in boost for mpg?

On highway, The eco mode should have zero boost....

what do you think?

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[Drex]

depends completely on the fueling Ford uses while under positive pressure (and at what pressure) vs load and RPM. More boost generally means more fuel to keep things cool (not efficient, but safer. Keeps NOx lower as well, but increases hydrocarbon output. It is a balancing act that it decided in real time. There is no right or wrong answer to your question, the answer is; it depends

 

[ZackDanger]

EcoBoost.

Pick one. You can’t have both.

 

[zombie]

Outerbank NON sas + 33 tires on 2.7: doing 15l/100km or 15 mpg


Wonder what would be worse beside downshifting the 10 speeds automatic vs increase in boost for mpg?

On highway, The eco mode should have zero boost....

what do you think?

Just lean into the fact that the Bronco has the aerodynamics of a brick sat on top of a slightly larger brick and weighs just shy of 5,000lbs, it is never going to deliver good fuel economy.

 

[ProdigyJKU]

I usually keep my 2.3/Manual in 5th on the highway. Fuel economy appears to be the same in either 5th/6th gear, since it usually runs constant boost to maintain 80mph in 6th. Where in 5th, it can normally maintain 80mph without needing the turbo. Plus the extra bit of rpm's and gearing keep it more responsive when passing.

It seems that the 2.7 can maintain fuel economy easier then the 2.3 when larger tires and lift kits are introduced. After modifications the 2.3 is no longer able to cruise at 80 in top gear without using boost. Where with the larger displacement of the 2.7, you can better chance of not needing boost in the highest gear, taking less of a hit to fuel economy.

 

[Chuck_Ruck]

Like I told Tyronne in Tuktoyatuk, "You have the wrong tool for the job" not a bad tool, just the wrong tool. It CAN work, just not as effectively for your intended purposes or needs. Tyronne needs a hard top for those brutal winters, you need an economy vehicle for MPGs.
@ZackDanger repeated my other sentiment, Eco or Boost, pick one.

 

[BigFootie]

Like I told Tyronne in Tuktoyatuk, "You have the wrong tool for the job" not a bad tool, just the wrong tool. It CAN work, just not as effectively for your intended purposes or needs. Tyronne needs a hard top for those brutal winters, you need an economy vehicle for MPGs.
@ZackDanger repeated my other sentiment, Eco or Boost, pick one.

Exactly! You can use a screwdriver as a crowbar, but a crowbar makes a crappy screwdriver. Just as a Prius makes a crappy off roader, but you can use a Bronco on the road!

 

[BroncoPQ]

Like I told Tyronne in Tuktoyatuk, "You have the wrong tool for the job" not a bad tool, just the wrong tool. It CAN work, just not as effectively for your intended purposes or needs. Tyronne needs a hard top for those brutal winters, you need an economy vehicle for MPGs.
@ZackDanger repeated my other sentiment, Eco or Boost, pick one.

Exactly! You can use a screwdriver as a crowbar, but a crowbar makes a crappy screwdriver. Just as a Prius makes a crappy off roader, but you can use a Bronco on the road!

I am aware that the bronco is not a prius.... but just questioning techno!

Boost vs downshifting!

 

[wrbix]

I’ll be the first here to say:
- boost vs downshift?…..don’t know.

…and HOPEFULLY the LAST here to say:
- our Broncos are not fuel efficient vehicles.

 

[BigFootie]

I am aware that the bronco is not a prius.... but just questioning techno!

Boost vs downshifting!

Sorry OP, wasn’t meaning to crap on you at all. Was just commenting on the right tool for the job and being my normal smart ass self. No disrespect meant to you.

 

[Wanted33]

As the old saying goes, "You can have boost, or you can have mpgs. You can't have both". IIRC most all new vehicle cut the gas off when the vehicle is coasting, so downshifting shouldn't be a problem. If I'm wrong here someone will come along, and correct me I'm sure.

 

[Flourman]

Experience from my F150 with the 3.5EB, downshifting usually gets better MPG. I found when towing in that F150, I could get better mileage when letting the motor rev out to 4K or so than letting the boost develop the HP (also helped to keep the motor cool when towing 9k lbs).

Usually the sweet spot for MPG (from personal experience) and needed HP is right where the motor starts the flat spot of the torque curve. Where the torque starts to build is where the turbo is spooling up and dumping a lot of air (and fuel) in. When the torque flattens, boost is less and relying the on the motor by itself to develop the torque.

From my experience, in eco mode with an auto, the vehicle short shifts (low rpm shifts) and gets to the highest gear as quickly as it can to keep the RPM’s low. When the motor feels load, it does hold that high gear but starts putting boost to it.

The earlier post about the motors using more fuel to keep cool is absolutely true. Under low RPM, high boost, the computer is dumping a LOT of fuel to keep the cylinder head temps down.

 

[BroncoPQ]

As the old saying goes, "You can have boost, or you can have mpgs. You can't have both". IIRC most all new vehicle cut the gas off when the vehicle is coasting, so downshifting shouldn't be a problem. If I'm wrong here someone will come along, and correct me I'm sure.

I would have a eco mode with zero boost on the highway

 

[Techun]

Downshifting and running higher rpm and no boost is *probably* more efficient in most scenarios. Will run cooler too, if you're talking sustained towing uphill.

 

[Exomodo]

My 2000 Ford Ranger 4.0 automatic 4x4 gets, at best, around 17 mpg with 160 hp. I have zero sympathy for your inquiry.
Motors are air pumps, most motors are most efficient at their torque peak and below. When you're making boost, you're using more fuel. If you don't want to use more fuel, keep out of the boost.
Turbo motors hate being lugged and never spun, choose your own adventure.

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