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'01 OUTBACK BIG MILAGE PLUNGE-WINTER ONLY

Got an 2001 OBW 2.5 now with 118,000 miles. Now in its 4th winter. Last year had BIG mileage drop off around December when temps got to be around 40 f. or less regularly. I am talking about a decrease from 25 MPG to around

16 MPG. No change in driving habits. Most mileage is daily 40 mile round trip at about 70 MPH. Very little stop and go. Have used Mobil 1 since beginning. Fuel filter, Plugs, Air Filter, PCV, Coolant and Oil all replaced more often than recommended. Tire pressure is always about 2 PSI over recommended (cold). Have changed thermostat twice. Heater output is same as always.

1st 2 years of ownership, this did not happen, just last winter, and now this. Last year mileage improved around April when things warmed up. Had check engine light around June that dealer said was Knock Sensor and replaced. Performance has remained consistent and it starts easy at all times. No check engine light.

What can cause this last 2 years WINTER ONLY mileage drop off ? I know SOME is to be expected, but this was sudden and drastic, last 2 years now (BUT NOT 1st 2 years).

Can it be temp sensor (air or coolant) ? Mass flow sensor ? Suggested O2 sensors to dealer last spring and they said that was rarely a problem (although I did not leave for service at that time).

Also have burned rubber smell from under hood when I park and get out, for several months now, that I cannot trace. Now occasionally smell it inside.

Any help greatly appreciated.

Thanks,

Tom

Reply to
Tom W
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Here in California we get winter "oxygenated" fuel but this only usually accounts for about a 1 or 2 mpg drop.

Reply to
Greg

Give us more information like how long since a tune-up and especially spark plugs and air filter. Have you used a fuel system cleaner like TECHRON FUEL SYSTEM CLEANER (walmart ~$ 6). Have you made any other changes like putting on oversize tires etc? ed

Reply to
Edward Hayes

I just bought a WRX so i dont know much about subs, yet. But i use to have a Ford Probe GT awhile back. The car had 2 O2 sensors. I had that same burning smell. I cant remember haveing a drop in MPG but the car ran fine, no CEL except sometimes when the smell was present, but it would go out after a few min. I let it go for awhile cuz i didnt know what could be causeing that smell and CEL, belts , clutch maybe ..seemed to happen when i would get on it hard. After reading some message boards people told me to replace the front O2 which was a common thing to go on those cars. I got a bosh universal one since the ones made specificaly for the car where more expensive. The smell never came back. The car had less then 75,000 miles when i started having that problem. I would tell the shop to check it.

Reply to
Michael Prosek

Oxygenated/winter fuel used where ya live?

Leave the defroster on, full time (with AC compressor running, by default)?

I'd suspect drop in tire pressure with cooler temps, but ya said that was covered...

Reply to
CompUser

MORE INFO ON WINTER ONLY GAS MILAGE PLUNGE.

No alterations to vehicle (tires or any) Techron used monthly. Plugs changed every 30,000. We do not have Oxygenated fuel in my area. Tire pressure about 2 Lbs more than factory spec (cold). Defroster not run much, and compressor won't run under 40 or so degrees anyway. All filters and other maintenance done MORE OFTEN than recomended

****NOTE**** THIS DID **NOT** HAPPEN 1st 2 WINTERS I OWNED IT****

Any help greatly appreciated.

Thanks

Reply to
Tom W

Sounds like you have done the maintanence and no check engine light so I'm thinking your O2 sensors maybe getting tired.

Reply to
Edward Hayes

Another thought is that the O2 sensor has a pre-heater which if bad will not cause a CEL in earler versions.

Reply to
Edward Hayes

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