It was a joke, poking fun at people who don't read manuals.

Note the manual link in my signature.

 

Does anyone have a whine and increase in engine load when in 4A? I just got my 2016 Screw KR and when 4A is selected the drivetrain whines as speed increases and you can hear the engine working much harder. Trying to remember back, but I seem to remember putting the Platinum I test drove into 4A and it drove identical to 2H.

 

I don't have a whine or have the engine seem like it's working harder, but I do hear more drivetrain noise. Figure this is normal, although I don't remember hearing anymore drivetrain noise on my 2007 Silverado when it was in 4A (although that was 8 years ago, maybe I have forgotten!)

 

Finally making use of 4A in my Lariat - works very smoothly and seamlessly... I turned on the power distribution meter on my gauge just to see when it would actually send power to the front wheels... Didn't feel anything, and didn't hear anything, but with wet/snowy roads, there's a lot of "road" noise, so hard to say if there's more driveline noise. But as it stands, I don't hear anything. Loving it (partly why I chose to upgrade to Lariat).

 

I leave mine in 4A all the time

 

I love 4A in my KR, but I agree there is an increased load feeling with it engaged. Honestly, I don't know there couldn't be, since the transfer case is engaged the whole time. I too use the power gauge when using 4A, and it does a great job of reducing front wheel bias when it doesn't detect slippage, or when turning sharply. It is very seamless in terms of not feeling when it goes in and out of 4WD, but yes - I do know what you're talking about regarding an extra load feeling.

 

My GM mechanic neighbor's opinion was to leave it in 2H as much as possible, at least with my prior Silverado. His reasoning was that the clutch packs in the transfer case engage/disengage a lot more often in 4A causing them to wear out faster and a transfer case was a fairly spendy replace/rebuild. He said that if you needed 4WD, use 4H instead of 4A.

Not sure if this holds true for the F150, anybody know? Based on this I tend to keep it in 2H unless road conditions are bad.

 

I had driveline noise and now it has gone away. at 7500 miles now.

 

I use 4A quite a lot. No increased road noise or engine load that I can tell. MPGs are pretty much the same too.

 

Took it to the dealer today for this and to document the gas pedal vibration in another thread. They called back and said the 4A whine, etc is all normal.

Just took a friends Platinum '15 around in 4A, no noise at all...