Finally, I think I’ve figured out how to calculate towing rates. On the side of the opening of the driver’s side door of my 2003 Subaru WRX is something called a GVWR, or Gross Vehicle Weight Rating, which for my WRX Wagon is 4,190. This is the maximum weight that the WRX should not exceed.
What was confusing me was how the tow weight of 2,000 can be justified given that the weight of the WRX is 3,220 lbs? If I towed at capacity, I would be at 5,220 lbs, exceeding the GVWR by 1,030 lbs (!!!)
What I was missing was the GCWR, or “Gross Combined Weight Rating” which for a 2003 WRX Wagon is 5,195 lbs. So, really, I can’t tow 2,000 lbs since the combined weight of the car plus 2,000 lbs is 5,220, exceeding the GCWR by 25 lbs = (Car weight + 2,000 lbs) – GCWR.
But, I’m not towing at that limit.
I am towing a 13′ Casita Patriot, which I’ve been told by the previous owner, an engineer, that it only weighs 1,200 lbs. My car (3,220 lbs) + Casita empty (1,200 lbs) = 4420 lbs. With the GCWR of 5,195 lbs, I have a margin of 775 lbs.
Now, while I did feel a tad “pushed” by my Casita, especially going downhill, I never felt out of control, especially when staying below 60 mph. I just placed my car in a lower gear and coasted down the Colorado passes. And, with my Turbo, I could easily go uphill at 60 mph.
So, to the question: is it possible to tow a 13′ Casita with a Subaru WRX Wagon? My answer is: “yes”. I’ve done it, over a Colorado Pass on Interstate 70 (I-70) both up and down.
But is it advisable?
There’s a lot of forum posts of people saying: get a bigger Tow Vehicle (TV).
And I get it. It increases the margin of safety, and when it’s your own, or other lives that matter you want to get as thick of a margin as possible.
But, here’s the thing: The GCWR is not an imaginary figure. It was calculated by the good engineers at Subaru. The tow hitch is factory installed, and rated at 2,000 lbs. Also, ALL vehicles can experience sway when towing, it’s not isolated to smaller vehicles.
Some extra features to bolster the argument that my Subaru WRX wagon is suitable for towing:
- Turbo – plenty of power to accelerate to speed
- Electric brakes – installed on my Casita with a controller installed in my WRX.
- Tow rated for 2,000 lbs.
- Never towed at the limit – I think I may have 200 lbs, at most, of additional cargo, not the 775 lbs limit.
- No freshwater tank
- No greywater tank
- Freshwater tank never used
- The most water I would bring is 8 gallons, and at 8lbs/gallon, that’s only 64 lbs.
- The Twin memory foam mattress should be 60 lbs (at most)
- The 2nd heaviest item is what is in the refrigerator. A large reusable bag of groceries averages at 38 lbs. I can’t fit anything more than that in my frig!
- The 3rd heaviest item is my bike, which weighs on 26 lbs.
- Let’s just say there are 200 misc lbs of “other stuff”: Clothing, cooking gear, etc.
Total of 388 lbs extra. Casita weight is 1,200 + 388 = 1,588 lbs
Add the WRX weight of 3,220 + 1,588 = 4,808 lbs
GCWR = 5,195. So, by my calculations, maxed out I am still 387 under the GCWR.
- Bike rack = 38 lbs
- 2 Propane tanks = 40 lbs total
- Marine Battery = 25 lbs
= An additional 103 lbs. 4808+ 103 =4,911 lbs.
Still 284 lbs under the GCVW.
Now, the next logical thing for me to do is to actually weigh the filled trailer and the tongue weight, which I plan on doing, but for now I feel I may need to search for a more suitable tow vehicle.
It’s math, people!
But: I’m not an engineer, and this is just back of the napkin calculations.
But then you look at what the Euro’s think of the WRX towing, and they say you can tow 2,400 lbs (!!!)
And some say with electric brakes on your trailer you can tack on an additional 1,000 lbs.
Anywho, those are my calculations to date. Sure, getting an FJ Cruiser would increase my margin of safety, but would also cost around 15k or more used.
I think the answer to the question, is it possible to trail a 13’Casita with a 2003 Subaru WRX wagon? I believe the answer is “yes”. I think you can be careful in driving (which you should be anyway), and it can be safe.
Is it advisable? I think going bigger, all things being equal like safe driving habits – but towing with a WRX is fine and within safety margins. When I see Big trucks towing trailers the size of houses I ask myself: which is more dangerous – that thing? Or my 13′ Casita being towed by my Subaru always below 60mph, and often much below that limit. Which is more dangerous – me driving like a granny, or that guy with that monstrosity at over the speed limit? I’ll take my “rig” anytime as a safer alternative.
Anyway, I am looking at a larger TV, but for now I am reassured by my calculations that I can trail my camper safely, and even reliably.