There is no difference in fuel economy between a Crosstrek and a Forester. There is a price difference but not by much. For you use in going off road a smaller car would be preferable. Dimensions: Width 1800 vs 1815, Height 1615 vs 1730, Length 4465 vs 4625. Shorter in height would be helpful when loading a kayak or sneaking through low hanging branches. Ground clearance (220) is the same for both. Foresters are good for families where you need the extra room for seating and luggage. Diesel fuel is worthwhile if you do a lot of driving in a year. Maintenance cost for a diesel can be higher than petrol. Diesel engines are very robust but so is a properly cared for petrol engine. Some users have found the Crosstrek very responsive and the bigger engine on the Forester not so. But this all depends on your use. There are paddle shifters on the Forester that will allow you to gear down if you need to pass someone on a short passing lane. On the motorway not a problem with the Forester.