Low MPG

[mcnea001]

1995 Subaru Legacy Wagon EJ22 195,000 Miles / Manual Trans

 

All:

 

Need some help with MPG.   Car is running great thanks to everyone on this forum.   Only problem is that I am getting MPG in the solid 20s.   I replaced one of the 02 sensors in May since I was getting a check engine light about 02 temp.   CEL went out and I have been driving happy.

 

Complete go through of the car last year.   New plugs / wires / fuel filter / thermostat / etc.

 

What am I missing?   She does smell rich when it first starts.

 

Thanks in advance!

Tom

[1 Lucky Texan]

knock sensors can be bad without throwing a code. It's one sensor where a cheap part seems to work as well for folks as OEM. Note how the pigtail is routed, clean the block under the old one, don't over torque the new one. Give it a coupla drive cycles to see if it helps.

 

engine temp sensor 'might' be another issue - maybe keeping the ECU in 'cold start choke' mode. If you car has 2 sensors for temp - it's the 2-wire sensor. Newer cars have a single part with 3 wires.

 

do you have a MAF? mmaybe carefully spray is with MAF cleaner?

 

might not hurt to use a vacuum gauge to check for vacuum leaks and blocked exhaust. google it, cheap way to check the 'health' of 3-4 systems on a car.Confirm decent air pressure in tires and brake calipers are greased and free to slide. Older car could have a few 'issues' spread across 2-3 areas.

Edited November 29, 2016 by 1 Lucky Texan

[dp213]

Are you getting 20 mpg or in the 20s? The best I've done is about 22 combined hwy and city

[whynot]

I only get 23-24 in my 99 legacy wagon

[idosubaru]

Check for lightly dragging brakes.

 

They run on a predetermined slightly rich mixture at first start up by design don't they? them once it's warmed up it'll use O2 sensor data to adjust air fuel ratio.

Only problem is that I am getting MPG in the solid 20s.

Tom

Sounds like normal gas mileage. Though 20's is a huge range - 29 is nearly 50% more than 20. That's like saying "I weigh 150-225 pounds"....

 

If you're not warming up the car while you scrape windows and driving perfectly flat land on an idealistic commute with summer blend gas then you aren't likely to get 30+.

[pzookey]

The best I have gotten out of my 97 OBW 5 speed is 26.5 mpg. The last tank was 21.1 mpg. I tend to drive it on the hard side so my mileage will be to the low side most of the time. I am happy when I get 24 mpg.