Bad99Pony

I read the manual on this...

(4A (4X4 AUTO)
Provides electronic control four-wheel
drive with power delivered to the front and
rear wheels, as required, for increased
traction. This is appropriate for all on-road
driving conditions, including dry road
surfaces, but is especially useful on wet
pavement, snow, dirt, or gravel.)

Does running in this hurt MPG and does anyone run in this mode all the time? Just curious...

kerry2

I tried 4A for a few kilometers on dry pavement and found that there seemed to be some mild vibration and driveline noise....it wasn't bad but it was noticeable....i think I would only use it if the conditions required it.

Livoniabob

Same here. Used it once or twice this winter.

kerry2

It is handy for the stoplight launch if you need to jump ahead and change lanes....no wheel spin, especially if it's wet out.

nra4ever

I found that it does hurt your mpg. I use it in slick conditions

130428

Some people run it in 4A all winter regardless of conditions. I only use it when it's just a little too sketchy to be in 2wd on the highway.
I dont like how 4A always seems to take a second or 2 to kick in when you need it.

zx12-iowa

I see 1-2 mpg drop in 4a. Works well tho.

2WheelDave

In 4A, I believe your hubs are locked, so the front wheels are "pushing" all the rotating members in the front differential right back to the transfer case. This is going to take a small amount of horsepower, especially when accelerating from a stop. That's bound use a little extra fuel. I was playing with mine a bit a couple weeks ago, with the "power distribution" display up on the dash. I could see that some power was being delivered to the front wheels almost all the time. Punching it on a gravelly road predictably resulted in the power distribution being about 50/50. I was surprised to see that the gauge said that there was some power going to the front wheels even on a clean, dry, paved road.

It is nice to have. My '13 made all kinds of unhappy noises and steered really strange if I engaged 4WD on anything with traction. I have to pull my travel trailer up a steep gravel drive to a paved road when I take it out of storage, I always do this in 4WD so I don't dig things up and the last bit where the truck was on pavement always made me cringe a little.

2015F150Platinum4x4

I've had mine in 4A for thousands of miles. It works very well. I thought I had a little more gear noise or vibration at first, but I either got used to it or it went away.

As far as gas mileage, I'm not sure. Most of my driving is around town so mileage sucks snywsy.

srg963

I've ran 4A for 25k miles. I notice no difference between 2 and 4A on the highway. You can monitor your display, to see when the front wheels get power.