Full time 4WD on Limited trim only? [Update: Platinum trim also]

[TheBat]

From the press release

4Runner will be offered in 2WD, part-time 4WD or Full-time 4WD. 2WD models will feature an automatic limited-slip differential (Auto LSD), and four-wheel-drive models have an electronically controlled two-speed transfer case with high/low range along with Active Traction Control (A-TRAC) and an automatic limited-slip differential (Auto LSD). An electronic locking rear differential is standard on TRD Off-Road, TRD Pro and Trailhunter grades. The Limited is offered with an available a full-time four-wheel-drive system with a center locking differential on i-FORCE MAX models, while this setup is standard on Platinum grades.

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[andim]

I’m not sure what about Toyota’s full time 4WD system would make it worse off-road?

My current Jeep has a locking rear diff. A part time 4WD with locking diffs compared to full time 4WD it's usually worse when you for example drive to a skiing area and the road is partially covered in snow/ice and partially dry. Then I'm driving in two wheel drive because I just can't switch the 4WD on and off every 200 yards.

The all time 4WD in my own experience is worse in two situations:
- you drive up a steep hill with loose gravel and a few rocks or roots. You basically need to maintain momentum. Then the computer in the car cuts power all the time and tries to route torque via braking or the limited slip diff to the tires that have still traction. This bogs down the car and the car just stops.
- the second situation is in my profile pic You drive in very loose fluffy sand and you need to maintain speed. Again the computer brakes wheels that are spinning in order to route torque to the wheels with traction. This slows down the car and you get stuck and you have to shovel while everybody else is laughing at you.

In both cases with a locked diff you just can give a lot more throttle (while the car is still moving and even then not too much) and you maintain momentum in sand or on the steep uphill sections. I also found it easier to crawl out of a mud puddle or such with the diff locked. But this could be due to the crawl control in the Jeep being not as good as Toyotas crawl control.

 

[zachavm]

From the press release



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Thanks @TheBat. Looking at the Tacoma site again I see it matches the 4Runner and says " "Automatic Limited-Slip Differential". So you either get a rear diff locker option or nothing. Disappointing, but not unexpected.

 

[Markarian421]

The all time 4WD in my own experience is worse in two situations:
- you drive up a steep hill with loose gravel and a few rocks or roots. You basically need to maintain momentum. Then the computer in the car cuts power all the time and tries to route torque via braking or the limited slip diff to the tires that have still traction. This bogs down the car and the car just stops.
- the second situation is in my profile pic You drive in very loose fluffy sand and you need to maintain speed. Again the computer brakes wheels that are spinning in order to route torque to the wheels with traction. This slows down the car and you get stuck and you have to shovel while everybody else is laughing at you.

Probably a difference in Jeep vs. Toyota full time 4WD? My FJ has full time 4WD, center and rear locking diffs, and various drive modes. Off road I shut off traction control and the brakes don't interfere with what I'm doing. In both the situations you mention I'd just have everything locked and be fine. There's a rock crawling mode that uses the brakes but that's for going slow.

 

[TheBat]

My current Jeep has a locking rear diff. A part time 4WD with locking diffs compared to full time 4WD it's usually worse when you for example drive to a skiing area and the road is partially covered in snow/ice and partially dry. Then I'm driving in two wheel drive because I just can't switch the 4WD on and off every 200 yards.

I can't speak for Jeep durability but in my 5th gen 4Runner with part-time 4WD, I just leave it in 4H in similar situations, did the same with previously owned Burb, Tahoe and Silverado all part-time 4wd. In cold weather even if it's dry the only time you NEED to be in 2wd is where tight turning is required like parking.