4/11/12 2:02 a.m.

Car is a 2006 Subaru Outback XT, yup, with the turbo motor and the five-speed automatic transmission. Yeah yeah, I know, it's a sacrifice one makes to keep the wife happy. It's done 90,000 miles and runs fine and shifts fine, if a little slower shifting than preferred. That was a known characteristic when new.

I'm getting 21-22 MPG in mixed driving and while it ain't great I expected that going in. I spent the first month shifting the transmission myself trying to get better mileage and it was actually worse, about 19-20. I'm almost always driving for mileage with low boost and when shifting myself keeping the revs down and get into top gear quickly.

Question is, why did I get worse mileage shifting myself, when I use fewer revs than in drive? Shifting myself uses sport mode (of course), and I'm speculating that in sport mode the torque converter only locks up in fifth gear whereas in regular drive it locks up sooner. At least that is what the seat-of-my-pants tells me is happening.

Can any Subaru gurus help me out? I just want to get as good of mileage as I can. Any suggestions on driving technique are welcome, too.

Thank you!


DaveEstey Dork
4/11/12 6:20 a.m.

I always got the best mileage when mine was full auto and I believe you're correct about the converter lockup.

The biggest gain I made was getting a tune, which cost me $200. I went from 23 mpg to 27 mpg and had more use-able power.

GameboyRMH GRM+ Memberand UberDork
4/11/12 8:49 a.m.

If it's anything like the Impreza slushbox, if it has the power/hold switch I find it much, MUCH nicer to drive using power mode and a light foot. Probably little to no effect on mileage though.

sachilles Dork
4/11/12 6:50 p.m.

I have the 2005 with the same tranny. I also found an improvement in fuel economy with a tune.

Apexcarver UberDork
4/11/12 7:06 p.m.

At 90k you are rapidly approaching the need for a trans service (flush) as well as plugs/wires. I did this to my mothers 2004 Impreza 2.5rs and saw an increase back up to the upper 20's that we saw when it was new. (sometimes I used to even get over 30mpg on a trip out of it)

So yeah, Trans flush/filter and plugs/wires.

Dont know if its the same motor, but done the timing belt?

4/11/12 7:41 p.m.

Apexcarver: Good thought on service. I bought it at 87K and just had the dealer do the 90K service. That included "service auto trans, minor" which I assume is a flush and filter but I don't know for a fact. Service record doesn't say anything about plugs and wires; I'll have to see what their recommended interval is. Timing belt isn't recommended until 115K which for me will likely be over two years from now; this car doesn't see much mileage.


sachilles Dork
4/11/12 7:56 p.m.

It's coil on plug FYI. I just did the tranny flush. Can't hurt, but don't expect a big improvement. My transmission has 234k miles on it. Motor has only about 5k. Tires can make a difference. However a tune is worth the money. Subies are pig rich from the factory.

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