awd to 2 wheel drive harm?

[monk50]

With the price of gas continuing its upward climb it has me wondering about the gas mileage gain putting the fuse in for 2-wheel operation.

 

I have a 95 subaru legacy with 200k on the clock and a 05 LL bean outback with 50k.

 

Questions

1. What is the experience out there of MPG gain in this?

2. More important does this cause damage? If so what kind and where?

3. Really would like to have some knowledgeable individuals response as to your professional experience. Your responses appreciated as to whether this is a good idea.

 

Thanks

Monk in NC

[nipper]

Buy a civic.

 

 

This has been discussed many times. It is NOT the power transfer to the rear wheels that cuts the gas milage. You have 2 rear axles, 4 cv joints, a rear differential, a driveshaft and a center bearing that consumes the extra fuel. Just putting in the FWD fuse does nothing, and in the end may even cost you a couple of hundred dollars or more, if the duty c solenoid burns up. The FWD holds the Duty C solenoid open. The Duty solenoid is not designed for that (Duty solenoids cycle on and off very quickly).

 

You can do more for your gas mileage and your wallet by keeping your tires properly inflated, and using your right foot cautously.

 

Subaru gives you the best gas mileage for a 5 passenger AWD car then any other car. The only way you can do better is by buying a 2wd 5 passenger car.

 

nipper

[MilesFox]

you would only gain from that if you were to entirely remove the rear axles as far as rolling resistance is concerned and the diff and driveshaft if weight is a concern

 

other wise the #1 thing you can do is inflate the tires to within 10% of max pressure (35 psi max/10% =3.5 [35-3.5= 31.5] essentially 32 psi.

 

go by the rating on the tire instead of the ratings on the door striker

[Hotshot]

If the gas milage has been somewhat lacking, a better idea is to make sure that it doesnt need any maintenance. Depending on the last time they were replaced, it may be good to check the air filter, fuel filter, spark plugs, wires, PCV valve, etc.

 

+1 on keeping the tires inflated. On any car, improperly inflated tires can really hurt gas milage, but on an AWD soob, it also cooks drive train components.

[JT95]

Have you replaced the O2 sensor? With 200k miles, it might be worth checking your sensors that affect air/fuel mixture, even if no check engine light has flashed.

[crazyhorse001]

If you're REALLY serious about going 2WD you'd need to disassemble the rear axles. Then put the stubs back into the spindles. Then you can pull the rear half of the driveshaft, and the rear diff. This will net you MAYBE 65lbs of weight savings, and MAYBE 1mpg

 

My thouhts are with the Gurus above. Give it a good tuneup, check the O2 sensor, and make sure the tires are properly inflated. These things will net you 3-5mpg if they've been neglected.

[nipper]

Well i would say 3pg which on 12000 miles a year would be a cost savings of about 71 gallons of gas a year Thats assuming 21mpb vs 24mpg). At 3.00 a gallon thats a savings of 213.00 a year ( 17.75 a month)

 

Now to me thats just not worth it. You can make that up by combing trips, walking more, driving like there is an egg under your right foot, keeping tires inflated, and telling your passenger to go on diet

 

nipper

 

edit - fixed my math mistake

[Durania]

I suggest this for MPG:

 

http://www.toyota.com/yaris/index.html

 

I would just leave it in AWD and not risk blowing out the duty C solenoid. The extra miles per gallon, if any, is not worth it.

[ericem]

Screw that, get a FWD impreza with a 1.8l. That should get you closer to 40mpg. Better yet wait for a Legacy or Outback with a 2.0L boxer diesel that gets 50mpg.