What's the MAX Speed when driving in 4x4 mode in a V6?

[MICA4R]

I hope you guys can help me out here.

I got into it with my buddy who thinks that I can go >60 mph while in 4x4 (v6) on the highway because the v8 and v6 have the same transfer case and hardware (minus the actuator of course). He takes his V8> 85mph while is in in "fulltime 4x4."

Is this safe for me to do that in my V6. The OM said <60MPH?

Whats your opinion or experience? Has anyone tried?

 

[bbauters]

It won't hurt anything. That being said, I don't because if I really need to be in 4hi then I don't need to be driving that fast. Fastest I've gone is probably 55 on the interstate.

 

[vvs75]

The OM do not state to drive <60MPH.
I drive my V6 in 4x4 mode most of the time 65-70mph, from time to time I do 90mph when I feel like it.

 

[Krazynative]

High speed (4WD)
Turn to “H4” with
speed below 62
mph.

This is from the OM... to me it reads you must be <62 when switching to H4 from H2. I have driven 85+ in H4.

 

[ToolmanJohn]

For your 2008, drive any speed you like. I don't recommend driving any SUV faster than 70mph , but since the V6 has a selectable full-time system 4wd system, it's not UN-safe for the 4wd system.

I usually switch to 4wd in December after the first snowfall. And then back again in the Spring :tongue:

 

[GG Beast]

This past weekend we ran a trail and on the way home realized we still had it in 4H. I was driving about 65 and slowed down to about 50 before switching back to 2H and it wouldn't set. We had to pull off the highway and do some 10mph driving before we heard a 'clunk' like going over a speed bump too fast and then it finally set back to 2H - Seems like there may have been a bit of binding going on, but not sure....

 

[simple]

The only speed limit I'm aware of is switching to 4hi less than 60mph. I would think there would be a number in the manual if it existed. Therefore it does not. For the people who voted 50, not knocking you at all, but where did you guys grab that number?

 

[sonerick]

This past weekend we ran a trail and on the way home realized we still had it in 4H. I was driving about 65 and slowed down to about 50 before switching back to 2H and it wouldn't set. We had to pull off the highway and do some 10mph driving before we heard a 'clunk' like going over a speed bump too fast and then it finally set back to 2H - Seems like there may have been a bit of binding going on, but not sure....

The Torsen center diff (tcase) on our V6 and V8 4Runners essentially puts the truck into "AWD" mode when in 4H. Although you have to be going <60 or so to engage 4H, driving at high speeds will not hurt it, it distributes power to the front and rear axles based on traction, preventing binding. This is what a Torsen center diff was designed to do and it is used in applications by Audi, VW, Lexus, et al. (Torsen - Wikipedia, the free encyclopedia)

Locking the center diff will put the truck into "true" 4wd mode where the axles only turn at the same speed and are locked together, which can cause binding when turning. I wouldn't recommend driving fast with the center diff locked.

 

[webby]

For your 2008, drive any speed you like. I don't recommend driving any SUV faster than 70mph ...

If you drive your SUV 70 mph or less on the Interstates in AZ, your SUV might just get run over, LOL. I always drive my 4Runner and my Highlander before that at 75-85 mph on the Interstates and run faster than that when passing. Feels quite safe to me on Interstate roads and when passing on quality two lane roads. But to each his own ...

 

[MrBobDobalina]

There needs to be more variables!

Above 85mph MIGHT be possible, but NOT unlimited!

 

[BlackWorksInc]

The Transmission and Transfercase is the same for the V6 and V8 IIRC, which means in 4Hi you are essentially in AWD. I've done at least 100mph+ in my V8 so 4Hi should be good for that.

 

[JB.]

Whew! Sure glad unlimited is leading the poll. Wouldn't look good to have a fact voted down.

Already mentioned, but the main point is that the V6 when in full-time 4WD drive mode (center unlocked) is virtually identical to the V8 which is permanetly in full-time 4WD. There's no speed limit based on being in full-time 4WD (AWD). Engaging is a different matter (less than 62mph) but even disengaging can be done at any speed.

 

[t4r4life]

This past weekend we ran a trail and on the way home realized we still had it in 4H. I was driving about 65 and slowed down to about 50 before switching back to 2H and it wouldn't set. We had to pull off the highway and do some 10mph driving before we heard a 'clunk' like going over a speed bump too fast and then it finally set back to 2H - Seems like there may have been a bit of binding going on, but not sure....

i had that problem too but i fixed it by replacing an disconnected vaccume line going into the diff

 

[sonerick]

Above 85mph MIGHT be possible, but NOT unlimited!

^This is wrong. Above 85 mph is entirely possible. In 4H (center diff unlocked), it is safe for the 4wd system to drive as fast as the ecu will allow (118 mph i believe).

There's no speed limit based on being in full-time 4WD (AWD).

Exactly. Audi's quattro AWD system is very similar to the 4H of our 4Runners. Those cars sure as hell aren't designed to be driven <60 mph, and the same applies to the T4R.

Anyone who claims otherwise needs to read up on how a Torsen center diff works.

 

[norcal2]

^This is wrong. Above 85 mph is entirely possible. In 4H (center diff unlocked), it is safe for the 4wd system to drive as fast as the ecu will allow (118 mph i believe).



Exactly. Audi's quattro AWD system is very similar to the 4H of our 4Runners. Those cars sure as hell aren't designed to be driven <60 mph, and the same applies to the T4R.

Anyone who claims otherwise needs to read up on how a Torsen center diff works.

I used to run my V-10 lamborghini (audi) awd at close to 200mph..no problem,, and others have gone as high as 250 in the texas mile...

 

[SkylineGTRracer]

A buddie named super werty on xru or aswerty on youtube runs around 110 in the quarter in 4wd hi to get great launches in a double cab taco so the same would apply to us.

 

[MICA4R]

Point(s) taken.

Ok, so yes, the manual says you should not engage 4HI above 100KM/HR (62MPH).

I stand corrected.:thumb3:

However, this is what I found today after doing about 85-90 MPH for 15 minutes straight: This morning in 4HI and then this afternoon in 2.


This is what I found in 4Hi:

- gas mileage was less on the built in computer (more resistance, makes sense)
- transmission pan was a LOT warmer to touch (v6 doesn't have a transmission cooler)
- acceleration feels much more "solid" (in a good way)
- cornering requires a little more effort on the steering wheel
- braking and deceleration feel a lot smoother
- tires seem to take a little more of a beating on the turns (more wear on the shoulders of the tires)

It won't hurt anything. That being said, I don't because if I really need to be in 4hi then I don't need to be driving that fast. Fastest I've gone is probably 55 on the interstate.

Agree.

There's no speed limit based on being in full-time 4WD (AWD).

Agree.

As a general rule I'd agree with all of you that the TORSEN can handle it, but if the roads are dry and I'm going 85mph, why strain the system for no added benefit? Can save some $ on gas and tires too.

Apologize for the long post.
I really appreciate everyone's input. I owe Mike a case of Shiner Bock...

-Andy

 

[V8 Brah]

Ok, so yes, the manual says you should not engage 4HI above 100KM/HR (62MPH).

I stand corrected.:thumb3:

However, this is what I found today after doing about 85-90 MPH for 15 minutes straight: This morning in 4HI and then this afternoon in 2.


This is what I found in 4Hi:

- gas mileage was less on the built in computer (more resistance, makes sense)
- transmission pan was a LOT warmer to touch (v6 doesn't have a transmission cooler)
- acceleration feels much more "solid" (in a good way)
- cornering requires a little more effort on the steering wheel
- braking and deceleration feel a lot smoother
- tires seem to take a little more of a beating on the turns (more wear on the shoulders of the tires)


Agree.


Agree.

As a general rule I'd agree with all of you that the TORSEN can handle it, but if the roads are dry and I'm going 85mph, why strain the system for no added benefit? Can save some $ on gas and tires too.

Apologize for the long post.
I really appreciate everyone's input. I owe Mike a case of Shiner Bock...

-Andy

What are you talking about straining the system. That makes no sense. The V8 is already full time 4wd. I've driven over 100 for extended periods of time.

In my 2011 S5 there is a full time AWD system with a torsen center and torque vectoring rear diff. I have drive that at 140+ w/o issue.

 

[PaulB-2006 T4R]

Last weekend while heading to the in-laws in the middle of North Dakota (Highway 13), I had my 4Runner up to 105 mph in 4WD before the wife squawked. If that road is dry I regularly travel 80-85 mph. There is nothing better to do than speed on their deserted 2 lane roads.

 

[JB.]

This is what I found in 4Hi:

- transmission pan was a LOT warmer to touch (v6 doesn't have a transmission cooler)

Probably a measurement error. There could be a slight difference on paper but nothing that should be obvious to two different touches, hours apart. If this is replicatable, you've discovered something important.


As a general rule I'd agree....the TORSEN can handle it, but if the roads are dry and I'm going 85mph, why strain the system for no added benefit?

Well ok, I'd say "strain" the system in a similar way, say, adding a roof basket would strain it.

As for tire wear, I can imagine scenarios where each system would produce more miles on a set of tires, but one thing can be said with certainty; AWD is more forgiving to longer rotation cycles.

Apologize for the long post.

Apologize? I'm impressed you did some actual testing.

----