You should get close to 30 on the highway. My Foresters that have bigger engines average well over 25 and are driven fairly fast.
Looks like you actually have the 2.5i, as otherwise a 2.0 would be the WRX turbo. Regardless, both are rather piggish on fuel, never really exceeding about 27mpg highway. Solution of course was Subie's CVT later on (2012 on Imp).
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