That's a fantastic question!
Never a CVT guy, but few have done more with AT Outbacks than I have. So I can speak for that confidently.
SPEAKING OF DIRT
The
FULLY STOCK 4Runner in 2WD is completely undrivable offroad on street tires. If anyone thinks otherwise, they have never driven a stock Subaru on dirt.
The STOCK SUSPENSION 4Runner on AT tires can survive dirt roads in 2wd, but is still a dreadful experience vs a Subaru.
BUT enter a 2WD 4Runner on QUALITY SUSPENSION and now we are talking comparisons. As a bare minimum quality suspension would mean 5100s or Eibach. However, my comparison below is based on better than that: 6112 on stiff springs and Icon 2.0 rear with Eibach springs.
So, if you drive a 2WD 4R with a QUALITY suspension on dirt, you are driving a fundamentally different vehicle from the stock one. Suddenly, the vehicle can actually stay straight over washboard and the next corner is no longer a fight for your life. Since the suspension soaks things up, you are actually handsomely outdoing a stock Subaru now, as your 4R offers a far more comfortable ride. I won't take it against a Subaru in corners, but it does corner with no drama.
From there, speaking of dirt, it becomes a matter of suspension. A Subaru can nowadays take an Ironman or basic Bilstein/Eibach suspensions. So in order to do better in the 4R you have to move up into a full 2.5 setup which will outlast the Subaru and offer a better ride quality.
Speaking of true 4x4 trails, neither the Subaru, nor the 2WD 4R apply.
However, there are many low end 4x4 trails where a Subaru is totally fine like Engineer Pass proper or Cinnamon Pass or White Rim Road and the like. Wherever speeds must be kept low for one reason or another and the terrain is seriously steep, a properly prepared Subaru will win or at least be much safer.
Speaking of high clearance trails
All of the above is obvious and self-evident to anyone with experience.
But things do get tricky when we start talking a high clearance trail. A Subaru or a 2WD 4R on quality suspension?
Three years ago, I would have said "Subaru!" Now that I have 4R experience with various suspensions, I will take the 4R in most cases.
As said already, the 2WD 4R will have to keep the speed up where the Subaru won't need to. BUT, when riding on a good suspension, that won't be a problem on nearly any trail a Subaru can make. The 4R will move faster and be more comfortable than the Subaru. It will carry 2.5 times the cargo payload (assuming my family's human and dog weight
).
On the other hand, there are cases where a Subaru should make it where the 4R might fail. This is likely to be loose steep hills as well as steep hills with rocks small enough for a Subaru to handle but steep and big enough to prevent the 4R from keeping its speed up. I think this can happen on a number of trails I have done on the OB, but on the vast majority a 4R on 2.5s will be better.
To sum it all up:
1/ Stock vs stock: Subaru
2/ 4R on 2.5 suspension vs modified Subaru: equivalent on dirt roads, 4R usually better on high clearance trails, if big loose hills present, 4R should drive the trail so that those be downhill.
3/ I will give a well-prepared Subaru the edge on a select number of low-end 4x4 trails that require low speeds and feature steep climbs. I would not really try any of those uphill in 2wd because of safety concerns.
