If I remember correctly for the last few years the Harley Davidson edition of the F-150 was available in either 2WD or AWD, well this year it appears on the website that it is available in 2WD or 4WD.

Is it a misprint and the truck is available in AWD or did Ford change the option of an AWD Harley Davidson Edition to a 4WD edition?

Thanks

 

They are AWD with a 4-HI setting on the 4x4 switch.

 

4wd is not the same as AWD and as far as I know AWD has never been available in an F series Ford truck.

 

My 2010 HD had 2wd, awd, and 4high.

 

It (AWD) was in the F-150 HD models...no transfer case and no low range 4X4.

 

HD = Harley Davidson, or "Heavy Duty" or what?

And what does that mean, the HD's had a "watered down" 4WD system? Why would anyone want that (lighter weight at the expense of low range capability)?

What does the 4-Hi mode do (vs. AWD)?

 

The F-150 Limited was also AWD. The HD, Harley Davidson is a sporty road truck like the Limited. Why would 4 lo be needed in such an expensive truck? These trucks really aren't marketed for work.

 

OK, but that still doesn't explain the difference between 4-Hi and AWD modes.

 

AWD is computer controlled. It's a rear drive biased system that engages the front drive when the system senses slip in the rear. The AWD system is also safe for use on dry pavement due to the nature of the transfer case and front end not being "locked" like a typical 4wd. IIRC the Harley also has a 4HI that allows the driver to lock in 4wd if the conditions warrant more traction.

The other models with selectable 4HI 4LOW are just that, a 2wd truck until you engage the 4wd yourself. 4wd should only be used in conditions where traction is limited (i.e. snow, mud, grassy inclines, etc). There is not enough "slip" in a traditional 4wd system to warrant use on dry or even wet pavement as the system components may bind and fail.

 

Thanks for the excellent explanation! If the HD's (and Lariat Limiteds) are available in 4x2 and 4x4 (which I assume from this thread is technically "AWD" + 4-Hi only), and the AWD only engages the front axle if slip is detected, then why is the HD/Limited mileage so much worse than the 4x2 model? The 4x2 does 14 city/18 hwy but the 4x4 does 13 city/16 hwy. That seems like a dramatic drop in fuel economy for a system that should not be engaged all that often. What am I missing here (other than additional weight from the 4x4 system)?

 

Well the weight helps...err hurts some. I think it adds about 300lbs. I cannot recall with 100% certainty but I believe that the AWD in those trucks can apply some front drive during times of acceleration. If that's the case then the mileage claims add up. Plus, in 4x2 I think you can still get the 3.15 axle (which is what the EPA likely tested) and the 4x4 is 3.31 or 3.55 at the lowest, so that likely is a contributing factor also.

 

This is from the 2012 F-150 Sourcebook:

2-speed Automatic 4WD System(1)
• Optimizes traction by transferring power to the
appropriate wheels when needed
• The system provides four available modes of
operation and is activated by using a rotary switch
on the instrument panel

– 2H (HIGH)

• Vehicle operates as a rear-wheel-drive vehicle
when 2H is engaged
• Helps vehicle provide optimal fuel economy

– 4A (Automatic Four-Wheel Drive)

• Set-and-forget function provides four-wheeldrive
capabilities when needed
• Under normal road conditions, most power is sent
to the rear wheels
• As road conditions require, engine torque is sent
to the front and/or rear wheels to help maintain
optimum traction
• Setting is appropriate for any driving, whether on
dry pavement or in adverse conditions

– 4H (HIGH)

• Setting provides electronically locked four-wheeldrive
power to both the front and rear wheels for
use at normal speeds on low-traction surfaces
• Intended for use only in severe weather and offroad
conditions including snow, ice, sand or mud
• Setting should never be used on dry pavement

– 4L (LOW)

• Setting provides four-wheel drive with full power
to both the front and rear wheels and includes
a lower gear reduction ratio for increased torque
multiplication to all four wheels
• Intended only for off-road applications that
require extra power including deep sand, steep
grades or when launching or pulling a boat out

This year, the transfer case is a little different. It now has a 4 LOW setting as well. This particular transfer case is standard on the 4WD models in Lariat, King Ranch, Platinum, and Harley Davidson models / trim levels. The remainder of the trucks in XL, XLT, FX-4, etc., have the standard two-speed transfer case which includes 2 HIGH, 4 HIGH, and 4 LOW.

 

^^^^^ awesome information.

Can someone please give John a little rep love? I'm currently in lock down.

 

I'm no auto engineer, but here's what I've learned along the way:

The difference between a 2WD system and any AWD or 4 WD system is the addition of a transfer case. The power out of the transmission goes thru the transfer case, then to the drive shafts. So you've got added weight plus added frictional losses of the case. I believe some 4WD front end systems will be less efficient then their 2 WD counterparts as well, even when operating in 2WD.

Any vehicle that is offered in 2WD or optional AWD will show poorer gas economy with the AWD model.

The AWD system like Audi/Suburu uses puts power out of the transfer case to both the front and rear driveshafts all the time; pretty much a 50-50 split.

Other AWD systems, which includes American trucks that are only AWD like the Denali, or the 4WD trucks that have AWD along with 2H 4H and maybe 4Lo, work differently when AWD is selected.
They basically run in 2WD until the rear wheels slip. Then the computer activates the front driveshaft and you're temporarily powering the front wheels.

However, there is a price to pay for this. When you select AWD, the system actually puts a slight amount of pressure on the front drive shaft so an engagement won't have a bump with it. So driving around in your 2012 Lariet 4x4 with your selector switch in AWD, or however they've labeled it, isn't free.

And that's why a 2WD Harley won't get the mileage of the AWD model. More mechanical drag, and 300 to 400 lbs. heavier.

 

*Repped! Now how is this different if I'm considering a 2011 model? Is everything the same except for the "4A" mode will be missing?

Did you mean to say "And that's why a AWD Harley won't get the mileage of the 2WD model. More mechanical drag, and 300 to 400 lbs. heavier?"

Or did I just completely miss the point of your post!?