Experiment: What do I lose with AWD?

[Christ]

Originally Posted by elhigh

Hey, I just went to some of the Scooby forums and read up a bit - it looks like activating the solenoid that is fired by that FWD fuse isn't a great thing to do - it's not designed for 100% duty cycle for extended periods.

I guess that's Subaru's way of saying that if you wanted 2WD you should've bought a motorcycle.

1 wheel drive?

[MetroMPG]

FYI, EcoModder member Xringer converted his Honda CRV from all wheel drive to front wheel drive by removing drivetrain components (axles, drive shaft).

He's since sold it. (No longer in his garage.)

I bugged him a few times to see if he'd do a writeup about his project, but he declined. If you ask him, maybe he'll share his experience/results.

[elhigh]

Originally Posted by Christ

1 wheel drive?

Check it out: ROKON: TrailBreaker

There's sport bikes, and there's utility bikes. You don't see many other motorcycles equipped to pull a disc harrow.

Or a plow.

Hey, it floats too. If I had to have a motor, I'd hold out for a Rokon. I'm not in any hurry to get anywhere. But I do want to be sure I'll get there. Rokon is a strong insurance policy toward the latter.

[brucey]

I've also heard its a very bad idea to run around with that fuse in. But it doesen't seem to be making a worthwhile diference in economy. If any at all.

As far as handling, I waited till after this test to test it. I punched it up a hill and it peeled out. Was kinda cute actually. Normally the car never has any wheel spin in anything but snowy conditions. Uphill in rain I still can't get any wheels lose.

[jcp123]

Originally Posted by pgfpro

This is about the same results I had on my dsm.

You still have to consider that if you could remove the transfer case drive-line and all the AWD rear parts and and replace them with a lighter FWD rear end parts you would increase your FE by a lot. All these parts have more mass and parasitic drag, so by reducing their mass and parasitic drag you would increase you FE.

This is the same as when testing a car in awd on a chassis dyno verse fwd mode on a chassis dyno.

That's what I was thinking...

[dwtaylorpdx]

I thought of another tidbit on the testing.

The viscous clutch that connects the front and rear drive always has about 5% lockup. Your never truly in 2wd in one. So removing the fuse keeps it from going to full lock but does not give 100% disconnect.

Another thing to check, connect a meter to the viscous clutch energy lead, and watch when it turns on. I think that you'll find that even in 2wd mode (If you have that) it turns on when accelerating and when traction control activates.

This could be a bad thing if you converted it to 2wd and then drove in real icy conditions... It would be a careful experiment to perform. Depending on how the antilock and traction control interface is programmed....

Dave

[RobertSmalls]

The 1995 Subaru Legacy wagon was available with 2WD or AWD, and the EPA rates them at 21/29 and 19/26, respectively. AWD adds extra driveline friction and over 100lbs of mass, some of it rotational.

Good thing you did A-B-A, or we would have drawn unjustified conclusions. For example, if you had tested first with dimples and then without, we might have figured dimples were good for +5% MPG.

I take it you did one run heading north, then one run heading south? I see clear evidence of wind during your FWD testing, and a hint of wind in the AWD testing.

[almightybmw]

Originally Posted by brucey

I've also heard its a very bad idea to run around with that fuse in. But it doesen't seem to be making a worthwhile diference in economy. If any at all.

As far as handling, I waited till after this test to test it. I punched it up a hill and it peeled out. Was kinda cute actually. Normally the car never has any wheel spin in anything but snowy conditions. Uphill in rain I still can't get any wheels lose.

That just means it's under powered

[brucey]

I didnt think about wind. When I was driving and turning around between the markers, I rolled the window down and never really felt anything. But I think it has to be moving at like 8 mph before you can even feel it with your skin?

The weather station also reported 0 mph winds.

As for power, it would spin the wheels some while in FWD but in AWD. I think I need to drop a 350 small block in it to make sure I can squeel all 4 tires as I barrel towards the next stop light.

[Peter7307]

Related to the above posts.
Ford Australia produce the model called the Territory in both AWD and RWD variants.
The website lists the fuel consumption at:

Territory TX RWD Territory TX AWD

11.6 (with 5 seats),
12.0 (with 7 seat option) 12.5 (with 5 or 7 seats)

Engines are the same but the transmission ratios are different due to the FWD transfer case.

Cheers , Pete.