l am thinking about trading down to a smaller vehicle for better gas mileage but l need to be able to pull my boat and four-wheeler trailers.

You will need to check the trailer weight restiction. They will pull a trailer.

only the 6 cylinder Subaru is worth considering-all the fours are too over-square and thirsty, with serious heat problems. My 1800cc L series was a disaster, and it had no torque!

A quick web search of ''subaru forester trailer capacity'' seems to indicate 2000 to 2400 lbs. depending upon the model year.

l had a 1983 Subaru GL 4WD wagon with less horsepower (carb. instead of fuel injection) which l think was only rated for 1000 lb trailer. l towed a 1000 lb camper, a 14' duck boat w/15 hp motor, & occassional a 4' x 8' trailer load of firewood. l even towed a 3500 lb Mercedes diesel with a towrope 5 miles once when the diesel would not start in sub-zero weather. It was still going strong at 139,000 miles when l sold it.

If this is a late model Forester, the towing capacity would be 2400 pounds.
Check with edmunds.com for older models.

l have an MY05 Subaru forester. Australian version so a 2.5L
It is naturally aspirated & l use it to pull my boat & also my trailer.
One time l filled my trailer with so much dirt to take to the tip that when they weighed it on the way out of the tip it worked out to be approximately 1.2 tonne of dirt would have been in the trailer. (1200kg) The trailer was unbraked but with that said the tip was not too far. l did have to use the low gear selector when taking off on hills for the extra torque.
When l moved from Sydney to Brisbane The trip is just under 1000km. we had all our stuff put in a huge move yourself trailer. It had 2 axles & was braked. l would say there was around 2 tonne in that trailer maybe more. We had fridge, washing machine, clothes & TV, lounge suite, 3 wooden beds. Table & chairs made of wood. & all the other odds & sods u might have in a house.
l guess it just depends on if ur expecting to be able to tow at a reasonable pace or tow with no lag that a V8 might provide.
If u tow on a daily basis maybe it wont be for you, but Subaru is with 2.5 litre engines r really ballsy.