What about highway? Steady highway?
In the mountains, it suffers on the steep hills and I don't see much improvement. Usually 8.5-9.0. For some reason, the Corolla doesn't get hurt by the mountain passes the way the Forester does. However, on the prairie, the Forester usually close to 8.0 at 100-110. Go 120 or more, and that upright windscreen sucks gas and we're back in the 9's.
In the spring in BC, thanks to lots of 90 limited highways, we saw 7.5 or so.
The best ever highway tank in the Corolla (4.eight) was on 90km/h mountain roads with tons of up/down. Must have much lower rolling resistance, allowing it to take more advantage of the downhills compared to the Forester. On the same stretch, the Subaru barely broke 9.0...