best time to put in 4x4 - Page 2

Been using it in 4WD Auto for the past week or so since it snowed.  It's been amazing.  You get a smooth straight start even on extremely slippery surfaces.  Dealer here in Canada also noted that you can change the modes at any speed and leave it in 4WD Auto.  Only advantage to keeping it in 2WD is fuel consumption; which I did during the summer.  I've notices an ever so slight increase in fuel usage...though some of it would be due to the colder weather too.
 

quote:

ORIGINAL: chenarm

I would never use 4WD Lock on dry pavement, in this mode the front and rear wheels, are assumed to turn at the same speed, if the tire diameter is not identical front to rear you can cause overheating of the transfer case and tire ware.  Even if the tire are identical, in a sharp turn, the rear tire follow a tighter radius than the front one, this means that during the turn the rear wheels are turning slower than the front.

Personally I always prefer 4WD Auto, even in perfect condition, since it removes a lot of the torque steer that you get when accelerating in 2WD.

Thats completely wrong.  You are thinking of a true 4x4 diff lock type situation.  With the outie it merely disrributes the drive nearer 50/50 but the diffs are not locked.  But I understand your confusion - calling it "Lock" is pretty silly and misleading on Mitsuibishis part.  They should call is "Sport" or something.

Some of the comments (from techs no less!) on this discussion are insane. You are not going to damage your vehicle under normal road circumstances by leaving it in 4x4 (either mode) - the only thing you can hurt is your fuel economy.

As regards speed, tdford has it right, but bascically its common sense - don't change it when you have your tires screeching round a bend for example where a change might upskittle the vehicle.  I've changed it between all three travelling at 75mph on a straight freeway, you can't tell its changing.  If it was easily damaged, there would be big warning stickers everywhere (as Euclid says) - just like you get in a full on 4x4 where you can engage low/hi box and or diff lock.

This is from the shop manual
 
*Tight corner braking phenomenon: When a 4WD vehicle makes sharp cornering in a paved road at low speed (ex. parallel parking), there is a difference in turning radius between front and rear wheels. If such a difference can no longer be compensated by tyre slippage, the vehicle behaves as if it is under braking.
The vehicle is tuned so that the tight corner braking phenomenon appears at a certain level with the drive mode selector in the LOCK position."
 
I know that the "lock" is not a Mechanical lock, like the 4WD from few years ago, and you are probably partially correct in that you will not damage the vehicle's drive system.  However you will increase the wear on the tires by using the lock on high friction surfaces, and I would concider that damaging.

Yes Mitsu did a bad job for describing the settings. 4WD Auto might be better called AWD, and 4WD Lock just called 4WD.
 
As far as increased tire wear, yes thats true but thats what you get when using all 4 wheels. Yes, old school 4WD systems your not suppose to really use on dry surfaces or in tight turning manuvers. Ours is not like those, so you can pretty much use it on any surface at any speed within reason. Like I wouldnt recomend switching to 4WD Lock at 100mph.
 
Just think about vehicles like EVO's and WRX's. They have ALL 4 wheels spinning ALL the time. And thats for better traction, and without damage.

I think that you would probably be causing more tire ware on “4WD Lock”, than on “4WD auto”, it’s not an old school 4WD but in the ”Lock” mode it is tuned to behave a bit like an old school system, with some of the same dry surface characteristic,  although to a much lesser degree.  4WD lock is sensitive to a speed differential between front and rear; it’s all over the 4WD section of the shop manual.  In fact if you run the car with the spare (smaller tire) in 4WD lock, it will automatically switch to 4 WD auto, in order to protect the coupling.  And if the difference is large it will switch to 2WD.
I haven’t read anything that suggests that you can not change the mode to “lock” at any speed.  The only thing that is not recommended is going from 2WD to 4 WD when the front wheels are spinning while the rear wheels are static, i.e. if you are stuck in snow or mud, in 2WD and you switch to 4 WD while you have your foot on the gas.

quote:

ORIGINAL: tdford

Ours is not like those, so you can pretty much use it on any surface at any speed within reason.

 
This is where common sense kicks in...
 
chenarm try using CAPS LOCK next time...

quote:

ORIGINAL: tdford

2WD Mode: Only front wheels with ATC
4WD Auto: Only front wheels with ATC, when ATC kicks up to 50% will be sent to rear wheels
4WD Lock: 50-50 to front and rear wheels with ATC

07-08 models do not have a locking differential, and is an Electronically controlled 4WD. So you CAN put into 4WD Lock on ANY surface, because the differential isnt locked. ALL wheels spin at different speeds. Which is what you want when you have slick surfaces to stop wheel spin. If you want wheel spin, like messing around in snow, turn off the ATC.

As far as what speed you can change modes.... 4WD Auto - any speed. 4WD Lock - I think the manual says, but probably no higher than 55-60. I will look to see.

I just wanted to point out that 4D Lock does NOT lock the centre differential, nor does it give a 50/50 distribution.
4D Auto is 60/40 front/rear. 4D Lock is 40/60 with a more agressive use of the rear wheels.
The Outie has a centre diff in the form of an electronically controlled clutch, mounted on the rear diff.

Complete details can be found here:
http://media.mitsubishicars.com/detail?mid=MIT2006083040260&mime=ASC



Cheers,



-Morten

quote:

ORIGINAL: morten
I just wanted to point out that 4D Lock does NOT lock the centre differential, nor does it give a 50/50 distribution.
4D Auto is 60/40 front/rear. 4D Lock is 40/60 with a more agressive use of the rear wheels.
The Outie has a centre diff in the form of an electronically controlled clutch, mounted on the rear diff.

Complete details can be found here:
http://media.mitsubishicars.com/detail?mid=MIT2006083040260&mime=ASC

Cheers,

-Morten

 
 
GREAT link. Thats what we needed here to clear up all questions. As I said before, there is NO locking differential. Thanks for clearing up the 60/40 thing, I thought it was up to 50/50. But thats even better! Up to 60% of torque can be sent to the rears. Just click the link, all questions should be answered.
 
"The driver can freely change the drive mode at any time."
 
"In dry conditions, 4WD Lock mode places priority on performance."
 
"Rear wheel torque transfer is increased by 50 percent over the amounts in 4WD Auto mode - meaning up to 60 percent of available torque is sent to the rear wheels under full-throttle acceleration on dry pavement."
 
"When in 4WD Lock mode, torque at the rear wheels is reduced by a smaller degree through corners than with 4WD Auto mode."
 
"At low speeds through tight corners, coupling torque is reduced, providing a smoother feel through the corner."
 
 
So as the info states, you can change the mode when ever you feel like it. Slow, fast, turning, wet, dry, doest matter. Which is what we want, and is great.

quote:

ORIGINAL: tdford

quote:

ORIGINAL: morten
I just wanted to point out that 4D Lock does NOT lock the centre differential, nor does it give a 50/50 distribution.
4D Auto is 60/40 front/rear. 4D Lock is 40/60 with a more agressive use of the rear wheels.
The Outie has a centre diff in the form of an electronically controlled clutch, mounted on the rear diff.

Complete details can be found here:
http://media.mitsubishicars.com/detail?mid=MIT2006083040260&mime=ASC

Cheers,

-Morten

Thanks for clearing up the 60/40 thing, I thought it was up to 50/50. But thats even better! Up to 60% of torque can be sent to the rears. Just click the link, all questions should be answered.

 
I thought the same - it's great its even better!!
 
Thanks Morten, great link.

On a loosely related, non-technical note...
I put it to the test today - going up VT-Rt.17 (Appalachian Gap) - a very steep twisty road - in the middle of the storm today past Mad River Glen and it was a rock!  I even paddle shifted to 1 on descents and really tight switchbacks.
I was very pleased.

If your Caps Lock comment is about the font that came out in my last post, I apologies, I edited my comment in word and did a copy and paste, not sure exactly why the font came out that way, it was not intentional.
 
I will admit that I was wrong about the car being damaged (other than the tires) when "Lock" is used, but it's not because the mode is inoffensive, it's because the vehicle will detect a potential problem and automatically switch modes in order to protect itself. 
 
As an aside, we had 14 inches of snow yesterday; using Lock in very harsh conditions certainly makes a very big difference.  
 

Here's a how it work from mitsubishi
http://media.mitsubishicars.com/detail?mid=MIT2006083040260&mime=ASC
 
And if you click on the right on download files (there's one in word format) you have graph explanation and all that.
 
 

quote:

ORIGINAL: smily157

.......... The system will not switch modes while moving, you can switch it while moving, but nothing will actually happen until you get to a slow enough speed to prevent damage. .........

I do not know what you consider "slow enough", as it will engage (change modes) at highway speed (70mph).  I have done so many times while pulling my boat / car dolly and you can feel the difference in how the vehicle handles immediately.  In 2wd, when towing a heavy load, the steering is very light and the vehicle floats around, as soon as 4wd lock is selected, no more floating around and the steering is back to normal due to power being applied at the rear wheels.

Morten & Roach, Thanks for the facts in the links above.  I read all the info on the Mitsu site when shopping for this vehicle 8 months ago.  It would be nice if folks would do a little research before they comment about something they do not actually KNOW about.  I heard it from a friend who heard it from a friend who....