a certified letter? to find out how to turn a ****? First, I have all the facts from the manufacturer... If you look, Ive worked for mitsu for 15 years.
second, how much do you need to know? Mitsubishi (and all other manufacturers) are NOT going to print engineering diagrams in their manuals. they tell you what you need to know, and thats 1)the 2WD position is 2 wheel drive, 2) the 4WD auto position takes care of slippage automatically, and 3) the 4WD lock position locks it.
what else is there to know? You want to know how many lines of coding have gone into the design? You want to know how much torque capacity the system transfers at a given amperage? thats information thats not going to be given by any manufacturer, because its not something that 99.9 percent of the consumer needs or wants to know. If you want more, you should become an engineer.

 

Well, no, I don't need any deep technical info, just decent facts about how much does the bloody 4WD Auto, for example, tranfers to the rear wheels. Is 4WD Auto reactive or continually active? Is 4WD Lock a low gearing (like the Nissan X-Terra)? Is it ok to go from 2WD to 4WD Lock around 60MPH if road conditions require it? Why does engaging any of the 4WD modes you lose power for climbing hills? That doesn't make much sense to me.... Well, I did NOT know you rowked for MItsu for 15 years. Maybe if I had known I could have saved $5.75 for the Certified letter and just asked you. Too late now. Well, as I stated on a previous post, my tech at my local Mitsu has no idea of what the clanking noise was when I first began driving forward. That is not reasuring! I had to send Mitsu a letter to get some answers. I mean, if you think about it, I am having to come to an online enthusiast forum to figure out what the heck is going on, while this service manager with 11years of exp with Mitsu has no clue about what is going on! Makes you uneasy, doesn't it?I guess my concern dictated my action of sending them a letter. Nest time, be sure I will ask you for advice even before going to Mitsu. That way I can probably tip the local tech on what is probably going on. Thanks! Chris

 

What I'm getting from the original article is:
4WD Auto
1. Some percentage of the available torque isALWAYS sent to the rear wheels.
2. The percentage incresease/decreases depending on the road conditions.
3. The maximum percentage of the available torque sent to the rear is 40%.The minimum is not specified, but based on the first statement it's bigger than 0% at all times.
4WD Lock
1. There isNO FIX amount of split between the front and the rear torque at any time (e.g. 50:50)
2.50% more torqueCOMPAREDTO4WD AUTO is sent to the rear at ALL TIMES.
3. Up to 60% of the available torque is sent to the rear, depending on the conditions.

I think there is still a lot of confusion about how the Mitsu 4WD system works. A salesman I sopke with (he is a Mitsu fan(atic) and he knows stuff about cars and specificaly Mitsu) told me that the 4WD Lock means 50:50 front-rear as per Mitsubishi training he attended in preparation for the Outalnder's launch.
Some clarifications from the source - Mitsubishi, would help the cause.

 

the system is simple. First, there is no low range. Second, the system applies the AWD clutch progressively to eliminate wheel spin unless its in 4WD lock, in which case the AWD clutch is pretty much locked (although the system will allow a tiny bit of slip when required for differentiation). In 4WD auto, it applies the pressure in an attempt to make the rear tire speed match the front (assuming they are spinning). It all happens in a split second; so fast you probably cant detect it. It only takes a couple milleseconds to apply current to the clutch pack and have it begin to transfer power.
you can switch the system at anytime you want, as all you're doing is progressively applying a wet clutch pack (similar to what's in your average automatic transmission, although MUCH stronger).
the system doesnt lose power when engaging 4WD... perhaps you're suffering from tire slip and the traction control/stability control is taking over?

 

The idea here is that of any other system on the market. The rear end is basically a center diff, and rear diff all in one. once in 4 auto it begins sending power to the rear tires (like a center diff) at this time, the more slippage it sees, the more clamping force it imparts and thereby sends to the rear tires.
In 4 lock, it fully engages the slipper clutch, and drives the rears 50-50, irregardless of slippage.
The idea of not running the system in 4 lock all the time, is that it is designed for slippery situations, and driving the rears at the same speed as the fronts for a long period of timeoverheats the system. Causing undue stress on driveline parts. Basically the clutch in the rear end needs to see some slippage all the time, thats what allows it to work properly, If it is locked, it is locked so that it is driving the rear tires the same speed regardless, sending power to the rear tires that are connected to anything that wont allow slippage creates stress and heat in the rear end, overheating it and causing failures. Basically, when in auto, the clutch slips, and when in locked, the rears need some slippage. locking it solid is bad juju. Manybrews is correct 100% if there isnt that slippage there, it will crab, and hop. Good explination.

dont run it in locked unless you are on snow, ice, mud, or off road and stuck.

 

Acording with Mitsubishi's description of the 4WD system, this statement is not correct.
http://media.mitsubishicars.com/deta...0&mime=ASC
I'm not trying to start an argument here, but discuss and understand how the system works.
4WD Lock, dos not split the available torque 50-50.
Indeed, at one point, this ratio could be possible, but not all the time.
At one point it could be 70-30 (F-R) or 40-60 (F-R).
I think the confusing part is coming from the fact that Mitsu states that 50% more torque is sent to the rear in 4WD Lock compared to 4WD Auto. But, byno means, this is not that the torque is split 50-50.

 

well Im not sure, but I think, by my interpretation that what I said, and you almost hit is the way it is. 4 auto, splits the amount variably, 4 lock splits it down the middle. If it werent like this, then why would they call it 4lock, why not just call it 4 auto, and 4 extra, 4 lock tells me the ratio is locked at a certain preset level. or am I missing something here.

 

While I don't know why Mitsu put the "4WD Lock" label on the ****, you cannot dismiss the explaination of this feature. It's writenin plain english:
"For driving in particularly challenging conditions, such as snow, the driver can select "4WD Lock" mode. In Lock mode, the system still apportions front and rear torque automatically, but enables greater power transfer to the rear wheels. For example, when accelerating on an upgrade, the coupling will transfer more torque to the rear wheels immediately, helping to ensure that all four wheels get traction. In contrast, an automatic on-demand part-time system would allow front wheel slippage before transferring power, which could hamper acceleration."
I tend to belive Mitsu's explaination than the interpretation of the "4WD Lock" label.

 

Most of the answers to your questions are in the original post. Mitsu has made things confusing by the chosen noenclature:

It seems the 4WD Lock is a misleading label here-that is the marketing department telling the engineers the consumer needs an identifiable word that is 5 characters or less to fit on the dial that sounds tougher than "auto" and isn't to confusing. The two modes appear to operate exactly the same mechanically, the difference is that the lock mode gets 1.5 times more torqe applied to the split range via computer controlled programming. The dial should essentilly read "Front WD bias (max 60F-40R split)" and "Rear WD bias (max 40F-60R split)". Mitsubishi torque split and some math based on the article:

Quoted from article "In Lock mode, the system still apportions front and rear torque automatically, but enables greater power transfer to the rear wheels".

In 4WD Auto torque is variable from some undisclosed minimum (probably 10-15%) up to 40%. In 4WD Lock, 1.5 times more torque is applied to that range Do the math; they state 50% more than auto up to a max of 60%. That means the max torque in auto of 40% x 1.5 times more torque (40%x1.5=20% more torque). 20%+40%=60%. There is where the 60% max in lock mode comes from. The two modes operate exactly the same mechanically, the lock mode gets 1.5 times more torqe applied to the split range. If the min. in Auto mode is 10% then the min in "lock" mode is 10x1.5 (5%) or 15%. The range being 15-60% in "Lock". Both modes allow for computer controlled wheel slippage in slow moving situations but it does state that in Lock mode, less slippage is allowed and some drivetrain noise may be noticed. On the fly switching of modes while moving should be fine since all your doing is applying a higher torque split curve to the programming.

Mitsubishi states several times in the article that the max rear torque distribution (in either mode) is reached under "full throttle acceleration". Mitsu has always been a street performance oriented manufacturer. Even the owners manual states this vehicle is designed for street use primarily. So, it seems that these torque splits are designed to be used in more extreme situations where better off-the-line dry pavement performance is required by directing more power to the rear in hard acceleration do weight distribution to the rear, hill climbing on loose soil , and on snow and mud where close to a 50-50 split is ideal. Auto mode seems best for mixed dry to wet to snow situations and you don't want to have to think about drivetrain stress in slow cornering.

So it appears nothing is actually locking, but that should not be a compromise in any way. The system seems to be designed for max. flexibility and thankyou Mitsubishi for giving us some credit by allowing us to have some control over it. This system combined with traction control ( I love how they refer to it as "virtual limited slip" thats exactly what it is) can be quite capable compared to conventional truck-type, old school 4WD. Better in snow certainly.

 

I really like all this, I think I have a more clear picture of how torque gets distributed (kudos to "ManeyBrews" and "Buzz" for the info.

So according to Buzz, even in 4WD Lock, the computer can still tranfer 60% (10% more than originally thought) to the rear to get you push after that snowbank. I think it's all good.

But in the end, I agree that this is a great system and maybe the nomenclature and lack of deeper explanation of this cool system in the manual has caused these questions here to spring up.

Finally, here is my question to you all: Do you even drive in 2WD mode or do you all drive in 4WD Auto the whole time, even on dry pavement on city streets?? (maybe we should have a poll on this).

This has been very enlightening! Thanks for the 411!