SPR SCBY pulled this 800 lbs of trailer and gear up a winding back road with several steep grades (~40 degrees) from ~2800 ft (108 F)at Vigin, UT to ~8000 ft at Lava PT (85 F) over 22 miles in Sept. With four adults! The temp gage never moved.
The draw bar weight was about 75#. The trailer (custom built) followed like it wasn't even there. We cruised at 75 mph on I 15 from Vegas to the exit to Zion and then about 60 mph to Vigin, UT from ther it varied. Round trip fuel economy was 21 MPG!
I did it with a 5MT. As long as the Gross Vehicle Weight, tow capacity, tire pressure... etc are not exceeded you should be able to tow up to 1500# (according to the manual) but I would reduce this by the total weight of the occupants/'cargo' (other than the driver) to be on the safe side. Draw bar weight must not exceed 150# but i've found that a target of 50 to 100# to be optimal. That way your rear suspension isn't maxed out. My trailer was custom made (to my specs for the RS) it was a 1500# gross trailer but had the axel replaced with a 3500# model so I could raise the ride height and use 16" rims (with my spare RE92s). The hitch was lowered 6" to accomadate the raised ride height.:sunny:
The RS rims would be a problem as the hubs are 5 3/4" 5 bolt pattern but the graphics are planned for stage 2 of the trailer.....tubular steel superstructure, custom fitted tarp (Sedona Red or as close as I can get) and a trailer 'gate' with 'Goes where no cars have gone before.....SUBARU Powered' and I would consider just about any 'Subaru' sticker I can get my hands for the side rails!
NIce Forester wheels on the trailer. I pull a small trailer with my MX bike on it almost every weekend about 200 miles to and from the track. My RS has a MT and it works fine. Most of the time I don't even notice the trailer is behind me but then again the gross weight that I'm pulling is no more than 500lbs. Damn I love my Subie.