Using "Manual" vs. "Locking Out Gears"

[rpold150]

I've been locking out 9 and 10 lately trying to keep it from getting into boost. I'm in West Houston where it's flat other than a very slight hill over a cross road. I'm trying to see if there's any significant mpg difference.

My EB with 3.31 gears will get into boost with the slightest increase in gas pedal if I leave it in 9 or 10th gear. If it's in 8th, I can get over an overpass without boost.

I've got 275/65/20 instead of the factory 275/60/20, so 34 instead of 33". I really wish I had gone with 3.55 gears now. The 3.31 just seems too low RPMs in 10th gear at 65-70 and on demand it will get into boost way before it thinks about downshifting.

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[DT444T]

i use lock out mode if stuck in 60 mph or less zones so the truck does not do the downshift up shift dance...

The highest speed limit near me is 55 so I'm in 10th at 60 all the time. It feel like you're wasting gears and fuel here.

 

[powerboatr]

The highest speed limit near me is 55 so I'm in 10th at 60 all the time. It feel like you're wasting gears and fuel here.

oh yes it will get to 10, but a small hill it down shifts. so i usually select to lock out top 2 gears to stop the up shift, down shift, up shift

 

[DT444T]

oh yes it will get to 10, but a small hill it down shifts. so i usually select to lock out top 2 gears to stop the up shift, down shift, up shift

Weird, I have the max tow package with the taller 3.55 gears but I do not have that same issue. Mine settles into 10th at 60 and will pull up a fair grade without needing boost.

Do you have a lift or larger tires or anything?

 

[HammaMan]

Weird, I have the max tow package with the taller 3.55 gears but I do not have that same issue. Mine settles into 10th at 60 and will pull up a fair grade without needing boost.

Do you have a lift or larger tires or anything?

Grades may be relative to the operator. I have 3.73s in the PB and have found it prudent to lock out 9/10 and possibly even 8 to stay out of boost. Doing such on my last trip through the hills improved mileage around 6%

 

[powerboatr]

3.31 gears, normal suspension
i find the truck will downshift VICE hold a gear and build boost to overcome the hill
the only way i get it to hold gears is in eco mode. eco mode for some reason will allow it to stay in 10th longer and builds boost up. weird it is
its the lack of tq at lows speeds of 60mph in 10th. i think eng is around 1100 rpm or less.
i think its fords programming, as my 6.7 3.31 gears would do same thing at 50 to 60 in 10th
it would downshift and ramp up rpm vice letting boost come up
i am talking modest over pass incline to clear a 2 lane road under.. not a steep climb
or a modest hill rise from flat ground .


then this afternoon, on a 2 lane passing a hay truck that was doing almost 60 in a 70, i had it in eco
changed lanes to pass and used about 3/4 throttle, truck first acted like pedal was dead, then down shifted to 7th and we were at 102 before i knew it as we merged back into the correct lane
my wife said...hmmmmm 100..

 

[Calson]

Using manual mode will also disable cruise control and hill decent control. I would only do this on flat dirt or gravel road surfaces to minimize upshifts when I let up on the accelerator.

 

[rpold150]

3.31 gears, normal suspension
i find the truck will downshift VICE hold a gear and build boost to overcome the hill
the only way i get it to hold gears is in eco mode. eco mode for some reason will allow it to stay in 10th longer and builds boost up. weird it is
its the lack of tq at lows speeds of 60mph in 10th. i think eng is around 1100 rpm or less.
i think its fords programming, as my 6.7 3.31 gears would do same thing at 50 to 60 in 10th
it would downshift and ramp up rpm vice letting boost come up
i am talking modest over pass incline to clear a 2 lane road under.. not a steep climb
or a modest hill rise from flat ground .


then this afternoon, on a 2 lane passing a hay truck that was doing almost 60 in a 70, i had it in eco
changed lanes to pass and used about 3/4 throttle, truck first acted like pedal was dead, then down shifted to 7th and we were at 102 before i knew it as we merged back into the correct lane
my wife said...hmmmmm 100..

I'm actually looking for just the opposite. If it stays in 10th, then the boost gauge will show boost with even the slightest additional press of the gas pedal. And it will increase boost way before it thinks about downshifting. To downshift, I need to go deeper into the gas pedal, but by then it's way into the boost.

But, if I lock out 9 and 10, with the RPMs a bit higher, I can climb a small hill without any boost.

From what people say, 10th low rpms with boost will drink a lot more gas than 8th with 500 more rpm and no boost.

 

[powerboatr]

I'm actually looking for just the opposite. If it stays in 10th, then the boost gauge will show boost with even the slightest additional press of the gas pedal. And it will increase boost way before it thinks about downshifting. To downshift, I need to go deeper into the gas pedal, but by then it's way into the boost.

But, if I lock out 9 and 10, with the RPMs a bit higher, I can climb a small hill without any boost.

From what people say, 10th low rpms with boost will drink a lot more gas than 8th with 500 more rpm and no boost.

mine in 10th at 60 will not even lugg , it will downshift unless i select ECO mode then it will hold 10th a bit longer and in some case long enough to clear the hill.
and boost will climb up to about 1/4 gauge display.
not sure why they program it to downshift with such a lite load.
it has tons of tq ...but the truck does not take advantage of it in normal mode

 

[diambo4life]

Mine is tuned. I call Manual and Sport the "Oh Shit" switch.

 

[DT444T]

Using manual mode will also disable cruise control...

Um, no? At least mine doesn't.

 

[powerboatr]

Mine is tuned. I call Manual and Sport the "Oh Shit" switch.

sport mode is a whole different animal
it stays in 8th at 60 to 65 and runs like a scalded cat
makes driving fun on winding roads

 

[Atlee]

Grades may be relative to the operator. I have 3.73s in the PB and have found it prudent to lock out 9/10 and possibly even 8 to stay out of boost. Doing such on my last trip through the hills improved mileage around 6%

Same here, except, will also lock 8th gear when pulling my TT. In the foothills of Virginia, this takes care of the majority of down shifts and s[pinning up the turbos.

 

[Atlee]

I'm actually looking for just the opposite. If it stays in 10th, then the boost gauge will show boost with even the slightest additional press of the gas pedal. And it will increase boost way before it thinks about downshifting. To downshift, I need to go deeper into the gas pedal, but by then it's way into the boost.

But, if I lock out 9 and 10, with the RPMs a bit higher, I can climb a small hill without any boost.

From what people say, 10th low rpms with boost will drink a lot more gas than 8th with 500 more rpm and no boost.

Same here, except I normally lock out 8th also. When I;m towing I lock out all overdrive gears.

 

[JExpedition07]

In Manual mode I dislike how long the transmission takes to react from the input to actual shift. It feels like an eternal delay.

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