This may seem like a silly question.... but how does the 4A (4x4 auto) system work?

It's supposed to have the truck in 2 wheel drive, then engage the front wheels if the rear wheels slip, however I can't tell any difference between 4 High and 4 Auto.

While in 4 auto, it sounds the same as 4 high, and under power distribution/off road settings, it shows that power is going to the front wheels, even though I'm on dry pavement.

Should 4 auto not have the truck in 2 wheel drive until 4 wheel drive is needed? ( rear wheels slip )

Thanks!

 

I actually have the same question, same thought process, and same results. I thought 4A would only kick in 4x4 if wheels were slipping, but that doesn't seem to be the case. This is my first vehicle with 4A.

 

Previous vehicles in my family have had a 4x4auto setting, and it worked just as it should... 2 wheel drive until 4 wheel drive is needed.

The salesmen for this truck told me about the 4A setting, and described it the same way, however every indication tells me that 4 wheel drive is engaged while in 4A, despite being on dry pavement

 

Been talked about here many times. It is a torque on demand transfer case. Yes all four wheels 'engaged' but little torque sent to front unless it is needed. there is a borg warner video a couple posts down in this thread about it.

https://www.f150forum.com/f118/how-d...d-work-343204/

I use it in snow and slippery rain so I don't spin tires and get moving.

 

that explains it then... thank you!

 

I recently used 4A on a trip through a snowstorm so I have plenty of experience watching the power distribution during the drive.

It it will always use 4 wheels accelerating from a stop and will not disengage unless you remove your foot off the gas.

When crusing on light throttle, it will stay in 2wd but on heavy or moderate throttle it will engage 4wd

I was able to force myself into a slow slip under light throttle on a turn at moderate speed to see how system would act. Even with the car slipping it maintained 2wd until I gave it hard gas.

My my basic understanding is that so far 4A is heavily reliant on your throttle input more than anything. Hard to compare it to other AWD systems unless they show power distribution but I like the 4A still

 

 

Much is dependent on the programming of the computer and how it interprets the information from the sensors.
The RAM's have the same borg warner transfer case and those guys are complaining that the trucks don't use the front wheels enough. Meanwhile here we are thinking it's using all 4 to often.

 

So hypothetically, it should save some gas over running in 4 Hi, but not a whole lot. 4 Hi does the power split as well, it just never disengages! That said, I'd probably use them exactly the same way... only when weather conditions warrant it on-road or if going off road.

 

FYI I don't think we're supposed to use 4H on pavement unless there's a lot of snow.