Conversion from AWD to Frontwheel Drive


#1

Has anyone ever tried removing the rear drive shaft and the two rear halfshafts on a AWD to improve gas mileage? I just bought a Subaru Legacy and dont need AWD for flat paved roads in the South. It should improve efficiency by at least 5MPG. I dont want to buy a different make , but want to know if the front CV joints/tranny would handle the extra strain. The savings over the life of the vehicle would be approx $5000.


#2

Subbie drive trains are the most efficient in design. Removing the components could save some in MPG, but not as much as you hope, maybe 1 if your lucky. However, the viscous coupler that hooks the power to the rear wheels is electrically operated, and can be disabled by simply pulling a fuse.

A friend of mine in TN does this with his Impereza. For most of the year, AWD is not needed. He claims an improvement of 3-4 mpg. But, in winter or bad weather, he simply replaces the fuse to re-engage the AWD.


#3

Don’t think that will work. All wheel drives have a center diff of some kind. Maybe a viscous coupler to even out the power delivery front and back. Take out one end and it will just spin the diff.


#4

BustedKnuckles is correct. If you consult your Owner’s Manual, it will give you information regarding the removal of this fuse (usually located under the hood, on the passenger side, near the firewall). It is recommended that this fuse be removed if driving on the donut spare, in order to prevent excess wear on the center differential.

(Note: These comments do not apply if you have a VDC model, whose more advanced AWD system does not require removal of a fuse when using the donut spare tire. However, on that model, it is apparently also impossible to deactivate the AWD feature as there is no fuse.)


#5

This “modification” has been known to destroy the clutch packs used in the Subbie automatic AWD.