One of the terminologies for this is 'ediff', although this is also used for "diff which has its internal clutches electronically controlled'.
In "super cheap e-diff with an open diff', only in place to save money, the results are horrid. There are issues where people with an incline cannot get out of their driveway, as the e-diff jockies back and forth, left to right, braking each wheel as it spins.
You may say "so?", but with an actual limited slip diff there is no braking, spin happens, and even if it is jockeying left/right, the freakin' car isn't braking whilst you're trying to get out of that driveay. Instead it's shifting power, and wheels are still working at it. You get out.
There are many conditions where slip is perfectly normal, and where braking to stop that slip is bonkers. Snow is another example. A great way to have your car spin out of control, is to suddenly auto-brake because it slipped the tiniest bit. Now, that tiny slip has become massive slip. The same holds for ice. ediff tech literally makes cars less safe, less driveable, less stable in snow and ice.
This holds true to all current stability and traction control I have tested on gravel, on pavement in rain, on snow, and on ice. I grew up driving on frozen lakes, and can use braking methods to steer, I can drive on snow and then when I turn on traction control?
And the result is the worst thing being done at the worst time.
Stepping back, we see forums replete with people complaining about auto-drive madness. I've seen people unable to exit their driveway with reverse-impact protection on, because their driveway is angled down to the road, and it detects the road as an object (it isn't... as the car drives down it angles up, but the radar just sees "object"). People complain about their car wildly veering into some turnoffs because it thinks that's how the road goes. People complain about brakes slamming on, when it's a tight turn and there are guardrails, which the radar thinks is an object.
The only true answer here is to disable ABS, thus preventing a large aspect of drive control. This is the only safe way to drive. And you make think "WHAT! ABS reduces braking distances!", yet this is misinformation, and absolutely not true.
ABS extends braking distances. Its only goal is to allow one to steer while braking hard. That's it. And while in absolutely perfect, and absolutely optimal braking conditions (dry pavement, cool day, lots of grip) ABS is almost as good as a human at distance-to-stop, when it comes to literally every other circumstance ABS is horrid.
Most directly, as an example, gravel or deep snow.
With gravel you want to lock the brakes up (to a certain degree). With many types of gravel roads, this results in you literally "digging in". Gravel starts to build up in front of the wheel. Braking distances are immensely reduced as a result.
Meanwhile, ABS prevents this condition, thus extending braking distances by 2x or even 3x. No, I'm not joking or exaggerating.
With deep snow the issue is just as stark. If you're driving in 6" of snow, and you brake hard enough to "dig in", snow just builds up more and more in front of the wheel. And another "trick" to snow driving is to brake VERY HARD, turn the wheel, then release -- and even on ice you often shoot off in the current direction of the wheel.
You cannot do either of these things with ABS.
Most of the reason for all of this, is that we do not have AGI. Nor do we have AI that is "a good driver". Instead, we have a bunch of algorithmic if/then statements, which do not even remotely match the wildly varying conditions that a drive will reach outside of a lab.
One of the worst situations I see with current autodrive, is that California, specifically SV, is one of the most temperate, perfect climates to drive in. Sunny almost all the time, with occasional rain. Developing AI systems, or even just simple driving algos / if+then statements in such conditions is as if driving in a lab.
No snow. No ice. You can see the paint on the road (there is no visible paint on roads in the winter in northern climates). Often, in snow storms you cannot even see the road vs the shoulder in a way a car can discern.
Yet here we have auto-drive tech being developed in Arizona, California, and sometimes Texas. And it's still wildly imperfect! Not even remotely ready for prime time, and it's only being deployed in absolutely perfect driving conditions!
I expect it will be 50+ years before we have autodrive capability that will approach true human driving capability in, for example, a snow storm.
Which leads back to using ABS for a diff?
It's just auto manufacturers reducing safety to save a few bucks.
Your specialized scenarios with gravel and snow are… interesting, but very misleading. A few inches of loose snow pushed up in front of your wheel does does nothing measurable to stop the car over staying within static friction, and if you aren’t already sinking into the snow, chances are that it’s packed too hard for this trick anyway. A thick layer of shifting gravel on the other hand stops you even without brakes, which is why we use it for emergency runaway truck ramps. I’d need to see some data to support if fully blocked wheels make a difference there - and even then, it would be a vehicle weight and tread-specific edge-case.
> ABS extends braking distances.
This is a very common and dangerous misunderstanding based on comparing the wrong datapoints. If your edge cases was true, it would still be wrong the majority of the time.
The best brake distance is always achieved by riding the brake a hair before any wheel locks up. ABS does not affect this - it might try to stop you from increasing brake pressure further past the limit of lock up, but it will not release pressure.
Locked wheels on the other hand always give you the worst possible braking distance short of forgetting to press the brake.
ABS shortens the brake distance from disaster to reasonable by managing wheel lockup when you did not, managing each wheel independently which you cannot, at speeds that a brake pedal does not allow, and using full-vehicle data you do not have available.
The mistake is to compare a perfectly modulated brake maneuver with a panic brake maneuver. What you need to compare is “perfect vs perfect” and “panic vs panic”.
> The best brake distance is always achieved by riding the brake a hair before any wheel locks up
The only way to know where that limit is, is to exceed it, cut back to rolling, then ease back in. I used to do this in my old Mustangs and Thunderbirds. Then when I got an ABS Continental, I was completely unable to brake effectively without engaging the ABS. And with ABS you can not just back of enough to get the wheels rolling again.
The worst was a Ford Focus with rear drum brakes and single channel ABS. One of the rear drums would lock up during normal stops (even with the wife driving, don't just assume that I'm an aggressive braker) and this would engage all four wheels ABS. This was on a brand new 2008 model and the dealership garage considered it to be normal behavior.
That said, my last ICE car was an Impreza with very good brakes and decent ABS.
On dry pavement, ABS is modulating the brakes to keep the tire rolling, it's mechanically doing threshold breaking. Did the Continental have a relatively high curb weight and relatively small tires?
In conditions with reduced friction it doesn't work as well as good manual braking (but you maintain steering).
The Continental was much heavier than a Mustang and heavier than a Thunderbird too. It was also front wheel drive, which may have had an effect. In normal driving I never had a problem with the Continental, but I like to test the limits of my cars in the rain and that Continental was certainly harder to brake in the wet past its limits than were the Mustangs or Thunderbirds. I don't remember all the details, we're talking decades ago, but for anything other than straight line breaking I preferred cars without ABS at the time. Even if ABS ostensibly helps you steer.
Most of the locking diffs now are automatic locking diffs based on differential wheel spin, like the G80. I can confirm that if you're using traction control, it seems impossible to cause enough slip to lock the diff. Then you can end up in a situation where you're on a icy/snowy hill and the car is applying the brakes due to excessive wheel spin before the diff will lock.
In "super cheap e-diff with an open diff', only in place to save money, the results are horrid. There are issues where people with an incline cannot get out of their driveway, as the e-diff jockies back and forth, left to right, braking each wheel as it spins.
You may say "so?", but with an actual limited slip diff there is no braking, spin happens, and even if it is jockeying left/right, the freakin' car isn't braking whilst you're trying to get out of that driveay. Instead it's shifting power, and wheels are still working at it. You get out.
There are many conditions where slip is perfectly normal, and where braking to stop that slip is bonkers. Snow is another example. A great way to have your car spin out of control, is to suddenly auto-brake because it slipped the tiniest bit. Now, that tiny slip has become massive slip. The same holds for ice. ediff tech literally makes cars less safe, less driveable, less stable in snow and ice.
This holds true to all current stability and traction control I have tested on gravel, on pavement in rain, on snow, and on ice. I grew up driving on frozen lakes, and can use braking methods to steer, I can drive on snow and then when I turn on traction control?
And the result is the worst thing being done at the worst time.
Stepping back, we see forums replete with people complaining about auto-drive madness. I've seen people unable to exit their driveway with reverse-impact protection on, because their driveway is angled down to the road, and it detects the road as an object (it isn't... as the car drives down it angles up, but the radar just sees "object"). People complain about their car wildly veering into some turnoffs because it thinks that's how the road goes. People complain about brakes slamming on, when it's a tight turn and there are guardrails, which the radar thinks is an object.
The only true answer here is to disable ABS, thus preventing a large aspect of drive control. This is the only safe way to drive. And you make think "WHAT! ABS reduces braking distances!", yet this is misinformation, and absolutely not true.
ABS extends braking distances. Its only goal is to allow one to steer while braking hard. That's it. And while in absolutely perfect, and absolutely optimal braking conditions (dry pavement, cool day, lots of grip) ABS is almost as good as a human at distance-to-stop, when it comes to literally every other circumstance ABS is horrid.
Most directly, as an example, gravel or deep snow.
With gravel you want to lock the brakes up (to a certain degree). With many types of gravel roads, this results in you literally "digging in". Gravel starts to build up in front of the wheel. Braking distances are immensely reduced as a result.
Meanwhile, ABS prevents this condition, thus extending braking distances by 2x or even 3x. No, I'm not joking or exaggerating.
With deep snow the issue is just as stark. If you're driving in 6" of snow, and you brake hard enough to "dig in", snow just builds up more and more in front of the wheel. And another "trick" to snow driving is to brake VERY HARD, turn the wheel, then release -- and even on ice you often shoot off in the current direction of the wheel.
You cannot do either of these things with ABS.
Most of the reason for all of this, is that we do not have AGI. Nor do we have AI that is "a good driver". Instead, we have a bunch of algorithmic if/then statements, which do not even remotely match the wildly varying conditions that a drive will reach outside of a lab.
One of the worst situations I see with current autodrive, is that California, specifically SV, is one of the most temperate, perfect climates to drive in. Sunny almost all the time, with occasional rain. Developing AI systems, or even just simple driving algos / if+then statements in such conditions is as if driving in a lab.
No snow. No ice. You can see the paint on the road (there is no visible paint on roads in the winter in northern climates). Often, in snow storms you cannot even see the road vs the shoulder in a way a car can discern.
Yet here we have auto-drive tech being developed in Arizona, California, and sometimes Texas. And it's still wildly imperfect! Not even remotely ready for prime time, and it's only being deployed in absolutely perfect driving conditions!
I expect it will be 50+ years before we have autodrive capability that will approach true human driving capability in, for example, a snow storm.
Which leads back to using ABS for a diff?
It's just auto manufacturers reducing safety to save a few bucks.