Like some explanation on how the Torsen, system works.

 

Most of what I'm writing is from memory, but here it goes. It's AWD all the time, not a part time system that kicks in when needed. The Torsen is the best part of the system. Most drivers keep it at H4F for probably 99% if not 100% of their driving. The H4L & L4L are locked, and is for extreme conditions where traction is compromised &/or gearing is needed.


H4F = High gear/AWD all the time/Free - center differential unlocked
H4L = High gear/AWD all the time/Locked - center differential locked
L4L = Low gear/AWD all the time/Locked - center differential locked


The unlocked allows for some wheel slippage but also directs traction to the wheel(s) with the most traction. The locked splits traction 50/50 front rear and does not allow slippage, so don't be there unless needed or it can cause binding in the drivetrain. The unlocked defaults to mostly rear wheel drive but the front wheels always have power to them, as high as 33% from what I've read over the years. Hope this helps. Enjoy your 4Runner!

 

Very helpful, thank you.

 

Yeah, just think of the H4L and L4L as the part-time 4WD system used in the Tacoma (for example). Only use these settings when there is no dry (that includes wet from rain) pavement involved.

Even in snow covered parking lots or with tight turns, you'll want to be using H4F otherwise the inner wheels will be forced to break traction reducing your turning radius.

 

But when you switch to HFL it locks the wheels to move at the same speed and turns off TRAC and VSC I think. We just had some snow and it seems to me when I went from H4F (where I could see TRAC and VSC engage when I slipped) to HFL the system was allowing wheel spin. So in HFL all wheels move at the exact same speed which is why you don't want to use it on dry pavement because it can cause drivetrain binding? When people say torque 50/50 that more reminds me of a highlander (or any other) typical AWD system where you can lock the torque but it isn't a true locking differential which makes the wheels spin all at the same speed. In the Highlander you can't lock the diff just torque 50/50 yet all wheel are on open diffs and just spin independently

 

Feel free to experiment, but H4F is where you want to be the majority if not all the time. I can only speculate the spinning you felt in H4L was possibly the tire meeting ice underneath the snow, or, you were in a turn where the inside wheel might spin while the outside wheel rotates.


I can't comment on the Highlander although I read somewhere in the past its AWD components had changed.

 

Yes i was on snow and ice.....i just think its a good thing that in H4L it allows wheel spin to some degree because in deep snow or mud you will need that as opposed to having the TRAC or VSC shut down a spinning wheel. I'm assuming that in HFL all wheels spin at exactly the same speed as opposed to H4F. I could test this by simply taking a corner and seeing if there is some binding but I agree in most driving conditions H4F is the way to go unless you are looking at a big hill with a foot of snow or driving through mud.

 

Found this.....suppose this is a two part question about locking the Limited’s Torsen Center Differential in high gears:

1. When should I? Or maybe I should just leave it unlocked even when it’s icy or snow-packed? 2. Why?

As a bit of background, the Torsen CD, when unlocked, distributes torque to both front and rear wheels at all times. The default torque distribution is 40% front and 60% rear, but it will change (max 30F,70R; 53F,47R) to increase torque distribution to the wheels with greater traction. It also allows the front and rear drive shafts to turn at different RPM’s (Torsen calls this “differentiation”). Without differentiation, you couldn’t turn corners on dry pavement.

When the CD is locked, it acts just like a part-time 4WD, like an SR5, with an engaged 4WD. No torque management and no differentiation. The torque distribution is fixed at 50F and 50R, and the drive shafts are locked to a single rotational speed. Relative wheel traction is ignored. And as with a part-time 4WD, the same warnings are given for a locked CD: driving on dry pavement is not recommended.

So, in snowy and icy conditions, the unlocked CD is already engaging both front and rears wheels. If there is a loss of traction, the CD will send to the wheels with greater traction. You are never in a position where no torque is applied to an axle. These all seem like good things to overcome traction loss in the snow. But is there an advantage to the fixed drive shaft rotation? Or maybe it just doesn’t matter all that much?

I know this is long-winded, but I just wanted to lay it out. The manual doesn’t have much to say about when to use 4HL. It tells you not to use it when tires can’t slide. I’ve asked a few people who are vehicle-savvy, but with no luck. By the way, when when using low gears in the 5th gen, there is no choice, only a locked CD in Low. I’m only asking about other driving circumstances – from highways and urban areas to unpaved roads, mining roads, etc.

 

Leave it unlocked.. 4WD fully locked also means it's easier to initiate 4 wheel skids by simultaneously breaking all 4 wheels loose in certain situations. I don't even engage 4x4 on snow unless I'm losing enough traction to the point of having difficulty keeping the vehicle moving.

Fully locked up can make it more difficult to get the vehicle (for example at an intersection) to turn as being fully locked forces some of the wheels to break traction in a turn due to each wheel following a different turning radius, as the wheels must rotate at slightly different speeds in a turn. Typically makes the vehicle tend to plow forward in a tight turn.

Torsen gearsets in a differential includiing CD are the best of both worlds.. let them do their job.

 

That is one thing I do not like about the new highlander it is part time AWD. the previous models were full time AWD.
The new 4Runner and Tacoma are they full time AWD. thanks.

 

Why did Toyota change the '16 limited 4runner?

I own a gorgeous 2016 Barcelona Red Limited 4-Runner. The dealer never told me it could not be put in 2-WD mode for better gas mileage, most of my driving is on dry road (the only way I ever drove my 2010 Tundra). I recently spoke to another owner with an otherwise identical White '15 limited and his average gas mileage is at least 10% better than mine (16.? vs. 14.5) which makes a big difference to me. Why did Toyota do away with this option? To save money? They also removed the entertainment systems ability to watch dvd's on the front information screen while the vehicle is parked with the emergency brake set, it would have been really nice to know this stuff before hand as I might be driving a year end White model 2015 instead, no vehicle review even mentions either change.

 

Limited 4x4's have been AWD since 2003 to the best of my knowledge. I'd take traction over mpg any day of the week, but that's me, and I own a 2003 4Runner SR5 4x4 that I choose to leave in the optional AWD mode. Folks owning the loaded models have almost always had worse mpg as their vehicles are heavier and engines are bigger (with most brands). You won't have any trouble selling the vehicle if u want something more economical. MPG is about the last thing on the minds of most 4Runner owners.


My advice is enjoy your vehicle or trade it in for a Highlander if u want better mpg.

 

Great info, I’m in the market for a 4Runner despite the rise in gas prices. Full time 4 wheel drive seems to be what I’ll be looking for.