My dealer says to keep my truck on 4A (4X4 Auto) full time in normal conditions. The manual says 2H (4X2) is best for fuel economy. Which one do you use?

 

2H, your dealer is less than smart. 4A is for when the road conditions may become less than ideal while you are driving. My Expedition is 4x4 and I told my wife, if you have any doubts about snow,ice, sleet etc, put it in 4A and you will be fine.

 

Dont have 4A Just Part time 4x4. In the summer, 2H all the time.

 

2H until it gets sketchy in the snow/ice then 4A until I get stuck and then 4L with locker when I need to unstuck lol

 

If the vehicle is designed to operate in full time 4X4 you won't hurt a thing leaving it there. You might see a very slight loss of fuel economy compared to 4X2. As long as the vehicle is designed for it you'll see better cornering performance even on dry pavement. It is basically operating like an AWD system used in Subaru's etc. I'd run a tank of gas through it both ways and see how much of a difference it makes. Unless the difference is significant I'd leave it in full time 4X4.

Back in the 70's full time 4X4 was common and popular. You couldn't buy a Chevy, Dodge, or Jeep truck for several years without it. Ford offered both options at the time.

Now if it is not designed to operate on pavement don't do so. You'll eventually break something and it since it isn't designed to be used on pavement you'll actually get worse traction.

 

I just run 4LO everywhere I go.
Nah, 2H. I only lock'em if I need'em

 

I use the 4A during heavy rainfalls to help avoid loss of traction on roads that puddle up water easily.

 

run a tank of gas both ways, like previously said.

4A will only engage the transfercase to apply power to the front wheels if the computer senses and slip or loss of traction.

I would just leave it in 4A. One less thing to worry about when the weather starts to get bad. Heavy rain, sleet, snow, ice, etc.

 

Also, very confused by the poll options, unless you can vote twice, how can you choose a "part-time" option and not another "part-time" option??????

 

How does the 4A system work on the F-150?

I'm assuming that in this mode, the front hubs lock in and stay locked in. Then, the transfer case has a viscous fluid coupling or differential that allows some slippage so that you can drive on pavement without damaging components. That's how the Jeep systems I'm familiar with work (except they use permanently connected hubs...no vacuum junk to fail).

Is F-150 different?