4A or 2H? Which is the best?

[BigGreenPony]

We have “less than ideal” roads up here in Alaska and I’ve noticed that 2H wanders less than 4A on dry pavement

Really? I think that 2H wanders more. kinda why I started this thread. Haha

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[Techun]

Doubt it all you want... I know math, for math is my ally, and a powerful ally it is.

My mileage is better in sport mode (probably due to my driving style), getting 23.5 mpg at 70+ mph in the Texas hill country is all the proof I need.

...ok I literally said unless it's mostly highway where it doesn't matter.

 

[mpeugeot]

...ok I literally said unless it's mostly highway where it doesn't matter.

You know that I drive around town and off-road too... Occasionally mall crawling.

The reason why I get better mileage in sport mode is because I spend less time in boost and more time in the peak efficiency range of the motor (as it holds the gears longer). I am sure that for some people (who have a different driving style) eco will net them better gas mileage. I simply am not one of those people.

 

[MistaGavin]

Really? I think that 2H wanders more. kinda why I started this thread. Haha

Yup, steering definitely feels heavier for me in anything other than 2H

 

[HotLap]

I put mine in sport, then immediately put it back in 2h. I would only put it in 4A if the weather is bad. Otherwise no need for 4x unless going offroad. If I were to hit trails that were just off camber without any technical sections, I would just put it in 4A and let it eat until it needs help.

This is my thinking as well, I can definitely feel it when 4A is engaged, can feel the FWD torque steer. My 2018 Raptor was the same could feel it as well, not necessarily a “bad” feel, but definitely heavier steering…

 

[Techun]

You know that I drive around town and off-road too... Occasionally mall crawling.

The reason why I get better mileage in sport mode is because I spend less time in boost and more time in the peak efficiency range of the motor (as it holds the gears longer). I am sure that for some people (who have a different driving style) eco will net them better gas mileage. I simply am not one of those people.

That peak efficiency range is under WOT. If you're just cruising at 30 mph then it's more efficient to be at 1300 than 2800 rpm.

You're right that sometimes more revs may be more efficient than more boost...but you're misunderstanding that "peak efficiency range" idea.

 

[Jkoren12345]

I came across this issue by accident. I usually switch my truck to 4A for adverse conditions, such as rain, snow, or sleet. This morning I did not turn it off after a big rain and I noticed that the front end felt a lot tighter and the truck handled reasonable better (Not that the handling was terrible before). So, I now have the question, will running my truck permanently in 4A reduce my fuel economy due to all the extra drive train? Has anyone on this forum tested this?

I'm currently get 18-19 MPG combined on a 2.3 Badlands Sasquatch manual truck.

I'm in 4A Sport Mode all the time. It tightens up the steering and everything just feels tighter + the dash looks better to me too...

 

[BigGreenPony]

That peak efficiency range is under WOT. If you're just cruising at 30 mph then it's more efficient to be at 1300 than 2800 rpm.

You're right that sometimes more revs may be more efficient than more boost...but you're misunderstanding that "peak efficiency range" idea.

That's not how efficiency is calculated. It's fuel flow versus peak power in relation to engine speed and torque. Automotive engineers, such as my self, refer to this as BSFC. Having less revs is actual worse for your fuel economy, hence why the 10R60 attempts to keep your engine around 2600 rpm to maintain the peak efficiency range. This range is about 2000-4000 for the 2.3 ecoboost.

Read this if you don't trust me:
https://x-engineer.org/brake-specific-fuel-consumption-bsfc/

 

[BadmansSAS]

That's not how efficiency is calculated. It's fuel flow versus peak power in relation to engine speed and torque. Automotive engineers, such as my self, refer to this as BSFC. Having less revs is actual worse for your fuel economy, hence why the 10R60 attempts to keep your engine around 2600 rpm to maintain the peak efficiency range. This range is about 2000-4000 for the 2.3 ecoboost.

Read this if you don't trust me:
https://x-engineer.org/brake-specific-fuel-consumption-bsfc/

Dont forget about variable cam timing. These have TI-VCT and depending on airload/RPM, you might be in an optimum power VCT mode or a best fuel economy mode or best stability mode...who knows. You'd have to log it at crusing to see what VCT mode you are in and what the intake/exhaust cams are being asked to do. Ford tuning is so variable that any of your comments could be correct, depending on a laundry list of factors. General automotive engineering knowledge goes out the window when dealing with Ford calibrations. Trust me.

 

[BigGreenPony]

Dont forget about variable cam timing. These have TI-VCT and depending on airload/RPM, you might be in an optimum power VCT mode or a best fuel economy mode or best stability mode...who knows. You'd have to log it at crusing to see what VCT mode you are in and what the intake/exhaust cams are being asked to do. Ford tuning is so variable that any of your comments could be correct, depending on a laundry list of factors. General automotive engineering knowledge goes out the window when dealing with Ford calibrations. Trust me.

Yeah, I can believe it! I used to work for Freightliner/Detroit Diesel and we did all kinds of trickery with the cals

 

[Techun]

That's not how efficiency is calculated. It's fuel flow versus peak power in relation to engine speed and torque. Automotive engineers, such as my self, refer to this as BSFC. Having less revs is actual worse for your fuel economy, hence why the 10R60 attempts to keep your engine around 2600 rpm to maintain the peak efficiency range. This range is about 2000-4000 for the 2.3 ecoboost.

Read this if you don't trust me:
https://x-engineer.org/brake-specific-fuel-consumption-bsfc/

"The 10r60 attempts to keep your engine around 2600 rpm"

No it doesn't. Do you mean under higher loads? Because then yeah, sure. But I'm talking specifically about under LOW LOADS (aka most of the time).

Your own link says that quite clearly, for a given low load (anywhere in the bottom of that example graph) lower rpm is better.

 

[BroncocnorB]

Maybe I shouldn’t coast up to red traffic lights anymore. Lol. As someone said earlier, 4A causes no harm to your drivetrain. Set it and forget it.

 

[Brian_B]

That peak efficiency range is under WOT. If you're just cruising at 30 mph then it's more efficient to be at 1300 than 2800 rpm.

You're right that sometimes more revs may be more efficient than more boost...but you're misunderstanding that "peak efficiency range" idea.

Gotta look at Boost, can’t just consider RPM by itself. The two are related but don’t directly correlate

 

[BigGreenPony]

Gotta look at Boost, can’t just consider RPM by itself. The two are related but don’t directly correlate

it shouldn’t matter. Mass flow rate is mass flow rate. Turbo or no turbo.

 

[Brian_B]

it shouldn’t matter. Mass flow rate is mass flow rate. Turbo or no turbo.

Mass Flow rate and turbo boost are directly linked.

RPM and Mass Flow rate are not.

Just go rev your engine sitting in Neutral.

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