I've been following this thread and been reviewing somewhat similar options. To the OP, I just ran depreciation on three cars, The Outback, The Tacoma and my own, a GX470, based on as close to an original purchase price of $28,500. Both Tacoma and Outback have models retailing new in that range, but my car was purchased for that price, two years old and at wholesale.
Running the numbers, based on the same mileage I put on mine in the time of ownership and considering I bought mine used, the trade in value of the Tacoma six years later, far exceeds the Suby and on par with my car. Had I paid the TMV price of 41K for it, I would have been way worse off than had I picked up the Tacoma I was considering at the time.
The point I'm making is, The Tacoma is holding its value very well and by the time you consider the loss on the trade, sales tax and in the case of this comparison, 3K additional depreciation for the Outback over 6 years, your savings in fuel would have to exceed well over $100 per month to realize any savings.
If the OP is paying interest on a loan, the additional interest on a new loan will have to be factored in as well, which may also rob him of any realized savings. I've factored in the cost of some expensive repairs I may be face with down the road as well, but it still come out to be cheaper in the long run, but the Tacoma is fairly cheap to repair and parts and mods are plentiful.
I really like the Outback and was really hoping to be more incognito than in my GX, but the numbers just aren't working and my truck has been paid off for over two years. I've even price out an even trade scenario and older Subys just need too much attention to make even that scenario really pay off....
The more I look at it, unless the current vehicle, is causing a financially strapping position, i.e. constant pricey repairs, super high payments or an all around pile of unreliable junk, it makes more financial sense to just keep what you have.
Now the financial gurus have been preaching this forever, but I had to waste days crunching numbers every which way to come to the same conclusion.
Keep the Taco, unless you really hate it, but don't trade it in. Those things are selling like crazy and you could at least minimize your losses, by getting near retail, in a week selling on your own, than letting the dealer wash it and make 5K or more on it. Just my 2 cents