[suby-do]

Hi Folks,

I recently purchased a used 1998 Forester S (AT) and would like to know the following: I was thinking of using only FWD during the spring, summer months as I don't go off road and I use the vehicle mainly on the highway.

If I remove the 20Amp fuse under the hood disabling the AWD to FWD could I (1) get better gas milage?
(2) would this have any negative effects on the AT, differentials?

 

[Peaty]

Welcome

To put the car in FWD (automatic only) you need to install a fuse not remove one. This topic comes up every once in a while. The upshot is you won't be doing any damage but you most likely won't be getting any better MPG's. Subaru does not recommend you drive that way all the time, it's only to be used on a temporary basis. The thing is, you will loose the AWD traction advantage and the damage you could do, quite possibly can be to your sheet metal in the event the AWD would have saved you from loosing control in say the rain or some other situation. In short it's best to leave the fuse out unless you are running the temp spare because you got a flat.

 

[pleiad7]

What Peaty said... and there is no advantage to FWD mode, as it won't net you better mileage.

 

[Quicksilver]

What Peaty and Pleiad said...with automatic transmission models, AWD in Drive (in typical summertime conditions) is 80/20 front to rear, with only minor improvement from going 100/0.
-Quick

 

[imprezaWRC]

If I remove the 20Amp fuse under the hood disabling the AWD to FWD could I (1) get better gas milage?
(2) would this have any negative effects on the AT, differentials?

Am I ask you a question ? , then , why are you going to drive a Subaru ? , To take the advantage of AWD and boxer engine , right?

You can disable the AWD system but you can't take any advantage , you will take more and more disadvantage ...

 

[twg]

If his car was a stick, where it's 50/50 all the time, I would expect significant increase in mpg...

but since it's auto, which defaults to mostly fwd... then, doesn't help much

 

[pleiad7]

If his car was a stick, where it's 50/50 all the time, I would expect significant increase in mpg...

but since it's auto, which defaults to mostly fwd... then, doesn't help much

Yeah, but the MT Subies don't have the option of switching to FWD. ;-) It's only a feature on the AT models.

 

[Peaty]

If his car was a stick, where it's 50/50 all the time, I would expect significant increase in mpg...

MT's are 50:50 in static but moving they will still move power around. People tend to get hung up on the ratios but the reality is it will be in flux depending on the conditions.

 

[erhayes]

The AT has a default front to back ratio of 60/40 but, varies continuosly depending on several factors. It is NOT mainly a FWDer. Anothing to consider if you use your car as a front only driver is that differental loading is normally split between front and rear. If you run FWD all the time you are putting a continously heaver load on the front differental which may lead to a shorter life. Just a thought.

 

[DonutKing]

No advantage but if you get ahold of a STi and do this it can be real fun to do launches and watch the tires smoke... I did it at the dealership I worked at It was great and someone bought that car that day...

 

[suby-do]

Thanks everyone for your expert advice!
I will keep the suby in continous AWD.