I'm getting about 17 mpg out of a 4 cylinder Eclipse.  Any ideas?

Does anyone have any tips for replacing the rear shoes on a 2004 mitsu
outlander fwd ? Parking brake adjustment, quirks, etc. I am capable of
this task. Would like to know more before tearing into them.

I inherited my daughters car which has a blow head gasket for the 2nd
time.  The last mechanic used a head saver shim but didn't double tork
the head bolts at high temp so now I have a nice path between the 3rd
and 4th cylinder.  The clutch is also suspect at this point.

   Mitsubishi service told me that the Outlander
needs it cheesy (not their words) rubber timing
belt replaced every 60,000 miles.
    Am I wondering, is there a retrofit kit that

   How does the Outlander do on unimproved
dirt roads with fishing holes at the end?
(They can get the hatchery truck down these
roads once a year or so.  But, everybody

I have a 4 cylinder 2006 Eclipse. I love the car, but the mileage is around
17MPG  anyone else having this problem?