Three months ago I got a 95 Legacy wagon with AT, my first Subaru with AT. Now that I’ve finished fixing it up (new struts, new tires, timing belt kit, replaced most fluids, fixed hole in exhaust pipe, new climate control switch, replaced blower motor, new spark plugs) the car is running great with 188,000 miles.

I looked in the manual to read instructions on the FWD option. It only mentions it in regards to towing the car. I had read on the web some places where people suggest you should use it if you have the spare tire on. Some people suggest it would be harmful to the car if you put it in FWD for the summer for improved fuel economy.

So what is the truth about using the FWD option? It seems the manual would give explicit instructions about this if it could be detrimental to the differential.

No fuel economy is gained on Subaru's AWD system with the fuse inserted.

Do a search on the forum, there has been many exchanges of ideas but it all boils down to added weight to the vehicle, not drag on the drive train.

Edited July 14, 20196 yr by Suzam

Have run in FWD with a 96 same as yours , not for gains but to avoid the rear binding issues. Never was a problem. Going back to AWD in snow and the car worked as it should. With snow those systems seem to show no symptoms but on dry you’d be annoyed especially when backing into a space. 

 

Good luck with it. 

Edited July 14, 20196 yr by moosens

using the FWD fuse when using the donut spare is a good thing

the Manual should mention this - mine did -  IF you need to change a front tire, you are supposed to put the donut spare on a back, put the good back tire on the front, and use the fuse to put it into FWD mode to protect the AWD system from damage

for towing, please always ask for a flatbed if you need to have your vehicle towed - the car MUST be running in order for the FWD fuse to work. If it is not running it does not work, and towing on 2 wheels will damage the AWD system

The FWD fuse is not for towing.  If you read it that way, you are misreading the Owners manual.  Subaru does not advise that, as it's useless without a running motor to drive the AT pump.

Never dolly tow any Subaru unless you remove the driveline.  Flatbed only.  

It is there for Donut spare use. Put the Donut on the back and run 2 matching tires on Front.  Never use the donut on the front.   Manuals trans cars don't have it because they are not electronic, and the basically open center diff in the MT cars will accommodate the tire size difference for a few miles at a time.

You can run FWD on the AT cars as much as you want, but it doesn't really help Fuel economy, maybe 1 MPG at most.  You are still dragging the rear diff and all it's weight around.

I have FWD run to a toggle for convenience, and so I can replace tires in pairs rather than in 4's.  I run FWD and then toggle into AWD when on gravel or snow.  

Edited July 14, 20196 yr by FerGloyale

The manual for my 1995 Legacy L has a section called:

”Towing with front wheels raised off the ground.” It then says to “Never tow manual transmission AWD vehicles with the front wheels raised off the ground.”

Then it says:

”If your vehicle is AWD with automatic transmission put a spare fuse inside the FWD connector located in the engine compartment and confirm that the Front-wheel drive warning light comes on. Release the parking brake and put the transmission in neutral. The Ignition switch should be in the ACC position while the vehicle is being towed.”

Under using the spare tire section it doesn’t mention FWD at all.

without the engine running, there's no pumping action to move fluid...so, maybe there's no pressure on the clutch pack and the drive shaft is just spinning its 'side' of the plates? Still, the trans fluid might overheat 'locally'....

 

those instructions seem odd.

Edited July 15, 20196 yr by 1 Lucky Texan

Use it to run different sized tires (spare).

You can use it when daily driving, but it doesn't reduce any inertia (all the components still spin), and the physical drag from the clutches being released is negated by the hydraulic drag on the pump to release those clutches. IIRC, on the phase 1 transmissions, no hydraulic pressure (engine off) will lock those clutch packs, so engine off will not disengage the AWD.

It can be handy to diagnose a transfer clutch problem.

If you're experiencing torque bind (car jolts when turning) due to low and/or old transmission fluid it will make that issue go away until you do the drain and fills.

I feel like I get more acceleration power with the FWD fuse in though slippage sometimes that doesn't occur in AWD mode. You can test the MPG's yourself with 2-3 tanks of fuel in each mode.

Edited July 15, 20196 yr by userface

13 hours ago, Ravenwoods said:

The manual for my 1995 Legacy L has a section called:

”Towing with front wheels raised off the ground.” It then says to “Never tow manual transmission AWD vehicles with the front wheels raised off the ground.”

Then it says:

”If your vehicle is AWD with automatic transmission put a spare fuse inside the FWD connector located in the engine compartment and confirm that the Front-wheel drive warning light comes on. Release the parking brake and put the transmission in neutral. The Ignition switch should be in the ACC position while the vehicle is being towed.”

Under using the spare tire section it doesn’t mention FWD at all.

 

This seems really wrong.

From the OWNERS manual?  or in a "Chiltons" or Haynes type serivce book,

I can't believe Subaru ever said to do that.  I've read alot of the owners manuals, obviously not from every year, but I've on;y ever read abuot the fuse for Spare use and always read NEVER tow any

The fuse is for the donut spare, not towing.