[JuneBug]

OK, I'm trying to figure these systems out. Somebody correct me if I have this wrong. This is for the 2WD configuration.

The TRAC (Traction Control) system controls the spinning of the front wheels by selectively using the brakes when starting off or accelerating on slippery surfaces.

When I press the AUTO LSD (Limited Slip Differential) switch the car uses the TRAC and controls engine speed as well. This system only works up to 31 mph.

The Electronic VSC (Vehicle Stability Control) uses anti-lock braking, brake assist, TRAC,
control of engine speed, as well as control of the power steering to prevent skidding when cornering or when making emergency maneuvers.

Does that sound about right?

 

[SteVTEC]

I have no clue what "Auto LSD" is, and no the front differential is not a true limited slip type. It's an open differential. Toyota could get sued for false advertising for this. It sounds like all it's doing is putting some RPM limit on the engine to prevent totally uncontrolled wheelspin and to go a little easier on the TRAC (ABS) system. The VSC system has various yaw sensors and uses the ABS wheel speed sensors to sense when the car might be in a skid, and which direction it's skidding in. It'll then apply selective braking if needed to individual wheels to help correct the skid. You'll typically hear a "beep-beep-beep-beep" nanny noise when it kicks in.

 

[monkey28]

Auto LSD means using brake to accomplish traditional mechanical diff. it apply brake
on one wheel, so the power can transmit to other wheel. which is same purpose on
mechanical LSD.

 

[bmorton]

Here's TRAC vs. Auto LSD explained by Toyota, from the features guide.

Outline of Auto LSD
 The Auto LSD achieves the equivalent functions of an LSD (Limited Slip Differential) through the use of a traction control function. For this reason, the contents of brake control are the same between Auto LSD and TRAC. When the driver presses the Auto LSD switch, this function achieves the LSD effect by regulating the hydraulic pressure that acts on the drive wheels and controlling the engine output in accordance with the amount of pedal effort applied on the accelerator.
 TRAC enhances the start off performance of the vehicle during low-resistance surface conditions, such as snow or mud, by restricting the acceleration effort during a start off in order to prevent the wheels from spinning.
 On the other hand, the Auto LSD tends to enhance the acceleration effort somewhat in order to apply greater drive torque to the wheel that is making contact with the ground. Thus, this function helps the vehicle get unstuck if a wheel loses its grip, and enhances the vehicle’s start off performance on high-resistance surface conditions such as gravel roads.

It also cautions you not to use the Auto LSD function for anything but starting off on a "surface with high resistance such as sand or mud" and not for normal driving.

VSC uses the "cooperative control" system to link together TRAC, ABS, EPS and AWD, if equipped, to control a slide.

 

[SteVTEC]

A real Limited Slip Differential will actively transfer torque from the slipping wheel to the wheel that's gripping, on any sort of pavement. There's nothing in Toyota's system that does that. The only thing applying ABS (TRAC) does is prevent the spinning wheel from getting "all" of the power as would normally occur in an open differential while still allowing the gripping wheel to get "some" power (because the spinning wheel getting less than all means the gripping one at least gets "some" :lol: )

The question is, where does the unused power go? In a fake "Auto LSD" system like this, the power that can't be used gets burned up in your brakes. In a REAL LSD differential the power gets transferred to the other wheel and is put to good use. No energy is lost.

So like I said, Toyota could totally get sued for this.

 

[bmorton]

It's hard to see how much of a lawsuit could be made out of it. They never claim that the vehicle is equipped with an LSD, only an "Auto LSD", which is Toyota's name for the sort of electronic simulated LSD that's common to many manufacturers. Toyota clearly explains in the owner's manual that this system uses the traction control system to regulate power and braking. The words "limited slip" don't even appear. I doubt much of a case remains to be made that Toyota deliberately intended to mislead people into thinking that an actual mechanical LSD was part of the package.

 

[SteVTEC]

http://www.toyota.com/rav4/features.html

Features:
Automatic Limited-Slip Differential (Auto LSD)


http://pressroom.toyota.com/presstxt/2009toyotakit/2009RAV4_sfo.pdf

STANDARD MECHANICAL FEATURES
· Limited slip differential (LSD) – auto (2WD Models)


They're advertising right in their press materials that it has a "Limited Slip Differential" when it absolutely is NOT a Limited Slip Differential. An open differential with traction control ain't the same thing as an LSD. Someone like me who actually knows what a real LSD is could buy the vehicle thinking it had one only to realize later that it didn't, and I'd be pissed as hell and probably have a legitimate case for false advertising. It's nice if Toyota finally admits they're lying about this when they describe what they mean by "Auto LSD" in the owner's manual, but who the heck reads the owner's manual of a car before they buy the thing? Most don't even read it after they buy it, but depend on stated specs and features to be accurate. This is not. Heck, even the "Auto" term tells you nothing. A real hardware based LSD is in fact fully "automatic" in that it requires no conscious input by the driver or external control system manipulation to function.

False advertising plain and simple.

 

[nobull1]

http://www.toyota.com/rav4/features.html

Features:
Automatic Limited-Slip Differential (Auto LSD)


http://pressroom.toyota.com/presstxt/2009toyotakit/2009RAV4_sfo.pdf

STANDARD MECHANICAL FEATURES
· Limited slip differential (LSD) – auto (2WD Models)


They're advertising right in their press materials that it has a "Limited Slip Differential" when it absolutely is NOT a Limited Slip Differential. An open differential with traction control ain't the same thing as an LSD. Someone like me who actually knows what a real LSD is could buy the vehicle thinking it had one only to realize later that it didn't, and I'd be pissed as hell and probably have a legitimate case for false advertising. It's nice if Toyota finally admits they're lying about this when they describe what they mean by "Auto LSD" in the owner's manual, but who the heck reads the owner's manual of a car before they buy the thing? Most don't even read it after they buy it, but depend on stated specs and features to be accurate. This is not. Heck, even the "Auto" term tells you nothing. A real hardware based LSD is in fact fully "automatic" in that it requires no conscious input by the driver or external control system manipulation to function.

False advertising plain and simple.

You are absolutely correct, but I bet they would say it is a limited slip differential by the fact the brakes limit the wheel spin. When we think think limited slip we think posi, trac lock or whatever. The true definition of the words limited slip differential could also mean abs controlled wheel slip.

 

[bmorton]

As long as it's described as an "Auto LSD" or "LSD - auto" it's not a false statement. Having the word "auto" in there specifies it, just not very clearly. Anyone who really cared about what Toyota meant by that term could find out fairly easily before purchase.

And surely no one who knows how a real LSD works would be confused about what was really in there once they got into the actual vehicle and saw the button on the dash, since presumably they'd be aware that a real LSD wouldn't require a button.

I don't think even a truly litigious individual could make much of a case out of this.

 

[BigSwede]

There is no strict legal definition of limited slip differential. Even for traditional mechanical LSDs there are different mechanisms out there... a clutch plate setup is the most common but there are other types also. The bottom line is does it work? Unless Toyota's setup is ineffectual, I doubt a lawsuit would get very far at all.

 

[SteVTEC]

Yes there's various terminology out there to describe a limited slip differential, but they all have one thing in common. The mechanism or implementation that makes the differential act with limited slip is internal to the differential. Toyota's mechanism is external. The differential itself is not a limited slip differential, yet they're calling it one anyways. What they call an LSD differs in operation significantly from how a true LSD operates. A real LSD does not need external manipulation to act in a limited slip fashion, but an open one does. Capabilities also differ significantly. An LSD has both traction and handling and overall performance benefits than an open even with external traction control doesn't. That's misleading and fair grounds for a class action lawsuit. Believe me, other manufacturers have been made to pay for far less than this. Even if something didn't go to trial, they might be willing to settle out of court to avoid all of the publicity and dirty laundry. Toyota would be the laughing stock of the automotive world calling an open differential with traction control a "Limited Slip Differential" and trying to sell it to people as such. I doubt Toyota would want the negative publicity.

When I was first looking at the RAV, I went down the spec sheet and did a "HEY COOL" when I saw that the 2WD models actually had a "limited slip differential". Didn't take me long to figure out that it wasn't really a true LSD though. But then again I'm a gearhead and would notice stuff like that. One giveaway was that it also has traction control, which isn't compatible with limited slips since it interferes with how the differential operates. Would the average person know that? Nope. Another giveaway is that limited slip differentials are usually $1000+ options if they're an option at all. It didn't seem very likely that Toyota was stuffing a more expensive differential into a cheaper car. I did some more digging and figured out they were lying. Would the average car buyer be able to figure that out? Probably not either. :roll:

I was going to get the 2WD version with the "Limited Slip Differential" and let that take care of my performance driving or snowy weather traction issues and also enjoy the lighter weight, better fuel mileage, and quicker rolling acceleration vs the 4WD model, except I was smart enough to know what a crock this was and avoided becoming a victim.

 

[SteVTEC]

There is no strict legal definition of limited slip differential. Even for traditional mechanical LSDs there are different mechanisms out there... a clutch plate setup is the most common but there are other types also. The bottom line is does it work? Unless Toyota's setup is ineffectual, I doubt a lawsuit would get very far at all.

A differential is a piece of hardware. "Open" or "limited slip" or "locking" are all qualifying adjectives used to describe that piece of hardware. For limited slip, you could add addtional qualifying adjectives to it such as "viscious" or "helical" to describe the specific type of limited slip it is, ie HLSD, VLSD, etc. It's all internal to the differential though. The functionality resides within the differential, whereas here it does not. Toyota is taking adjectives meant to describe their traction control system (limited slip, woohoo!) but changing the location of where they should properly reside. If the differential itself is not "limited slip" then they should not be parking the words 'limited slip' in front of that differential.

Agree or disagree, Toyta is on extremely thin ice here.

In the least case, anybody considering this vehicle ought to know that what Toyota is calling a "Limited Slip Differential" ain't a limited slip differential. It's an open differential with traction control which is absolutely NO different than what any other manufacturer does on their FWD cars. If anybody bought this car in part because it has a "Limited Slip Differential" as opposed to another car which may have merely had "traction control", then guess what? You got conned, and if you're upset enough about it, could file a class action suit.

 

[bmorton]

It's still grasping at semantics and a strict definition of a term. Again, nowhere does Toyota state that the vehicle has a limited slip differential. Instead, they say it has an "auto" LSD. Qualifying it like that makes a difference. A court would have to be convinced that the term "limited slip differential" was either sacred or enshrined in law to the point where a reasonable person would be misled by Toyota's name for the feature.

It would also look at precedent - how do other manufacturers refer to such a system? VW/Audi call it EDL (electronic differential lock). On a Chrysler, it's BLD (brake lock differential). Neither of these actually lock the differential. Marketing terms that do a slightly better job than "Auto LSD" of explaining what's going on? Or just two more court cases?

If anyone bought this vehicle with the belief that it has an actual LSD, they're guilty of not doing sufficient research. Hardly a misleading con job on the part of Toyota.

 

[BigSwede]

There is no strict legal definition of limited slip differential. Even for traditional mechanical LSDs there are different mechanisms out there... a clutch plate setup is the most common but there are other types also. The bottom line is does it work? Unless Toyota's setup is ineffectual, I doubt a lawsuit would get very far at all.

A differential is a piece of hardware. "Open" or "limited slip" or "locking" are all qualifying adjectives used to describe that piece of hardware. For limited slip, you could add addtional qualifying adjectives to it such as "viscious" or "helical" to describe the specific type of limited slip it is, ie HLSD, VLSD, etc. It's all internal to the differential though. The functionality resides within the differential, whereas here it does not. Toyota is taking adjectives meant to describe their traction control system (limited slip, woohoo!) but changing the location of where they should properly reside. If the differential itself is not "limited slip" then they should not be parking the words 'limited slip' in front of that differential.

Agree or disagree, Toyta is on extremely thin ice here.

In the least case, anybody considering this vehicle ought to know that what Toyota is calling a "Limited Slip Differential" ain't a limited slip differential. It's an open differential with traction control which is absolutely NO different than what any other manufacturer does on their FWD cars. If anybody bought this car in part because it has a "Limited Slip Differential" as opposed to another car which may have merely had "traction control", then guess what? You got conned, and if you're upset enough about it, could file a class action suit.

I should have added that I don't really disagree with you, I'm just saying it might not be enough to sue over successfully.

 

[SteVTEC]

It's still grasping at semantics and a strict definition of a term. Again, nowhere does Toyota state that the vehicle has a limited slip differential.

It says it right in their press kit, and online also.

http://pressroom.toyota.com/presstxt/2009toyotakit/2009RAV4_sfo.pdf

/forums/album_pic.php?pic_id=7972

Instead, they say it has an "auto" LSD. Qualifying it like that makes a difference.

How so? A true limited slip differential does work "automatically", and hence it's not changing the definition sufficiently.

A court would have to be convinced that the term "limited slip differential" was either sacred or enshrined in law to the point where a reasonable person would be misled by Toyota's name for the feature.

A generic "limited slip differential" is more or less a pretty common term to describe a differential that internally can limit slip and transfer power around. Since it works "automatically" without user intervention or conscious manipulation by a control system, I don't feel that just the term "Auto" changes the meaning enough to tell someone that what they're calling a "Limited Slip Differential" is anything but a "Limited Slip Differential".

It would also look at precedent - how do other manufacturers refer to such a system? VW/Audi call it EDL (electronic differential lock). On a Chrysler, it's BLD (brake lock differential). Neither of these actually lock the differential. Marketing terms that do a slightly better job than "Auto LSD" of explaining what's going on? Or just two more court cases?

I'm not the least bit familiar with those systems or what they're supposed to do, so I can't comment on the absurdity (or not) of how they're named and whether they're misleading or not. Then again, none of those are universal type terms like "LSD" is.

But speaking of precedent, funny how on the Camry specs they don't even mention a differential type at all and just say that it has VSC and TRAC available as options. Oh but move up to the RAV4 and now it's an "Auto Limited Slip Differential"! Not just VSC and TRAC any longer, even though it's the same exact thing. Maybe there's some subtle differences, but the concept of operation between the Camry and RAV4 are the same. Open differential plus traction control / ABS to control wheelspin. On the Camry it's just VSC/TRAC, but on the RAV now you have a "Limited Slip Differential". puhhleaze. :lol:

If anyone bought this vehicle with the belief that it has an actual LSD, they're guilty of not doing sufficient research. Hardly a misleading con job on the part of Toyota.

If it says on the damned spec sheets that something has a "Limited Slip Differential" (auto or not), then I fully expect that the car will have a real hardware based internally limited slip differential, as that's generically what the term has come to mean. You can't be guilty of not doing enough research when Toyota is lying right out their ass on this, and assuming that their customers will be stupid enough to not know the difference. Any case brought wouldn't necessarily have to come to trial. Things like these are commonly settled out of court just to keep things quiet and avoid all of the bad publicity and embarassment.

Believe me, if angry Honda owners can get somewhere suing Honda for bad transmissions all under the idealistic notion that everything Honda builds is perfect and would never fail (they did get somewhere), then Toyota owners could sue about Toyota lying out their butts about the non-existant "Limited Slip Differential" in the RAV4. 8)

 

[SteVTEC]

You are absolutely correct, but I bet they would say it is a limited slip differential by the fact the brakes limit the wheel spin. When we think think limited slip we think posi, trac lock or whatever. The true definition of the words limited slip differential could also mean abs controlled wheel slip.

But then that's external to the differential and has nothing to do with the differential itself. Hence, why are they calling the differential limited slip if it needs brakes to limit slip? The differential has no means to limit slip, hence it's not a limited slip differential. There's a traction control system that limits slip, but not in the differential.

 

[SteVTEC]

I should have added that I don't really disagree with you, I'm just saying it might not be enough to sue over successfully.

You might be right, but you don't have to be able to win a court case to get a settlement either and win that way. All you have to be capable of is bloodying Toyota's nose enough and create enough bad PR and other headaches for them to want to settle out of court. :wink:

 

[RAV4Don]

SteVTEC, I completely agree with you. An open diff with traction control is not a LSD in any way.... other than wishful thinking.

My Chevys have real LSDs. I have an oem GM 14 bolt 9.5"ring gear in my Chevy truck, I replaced the oem whimpy LSD with an Eaton unit years ago. I have the oem GM 7.5" in my Camaro, but it came with the SS optional Torsen LSD that has no traditional clutches. :wink:

 

[BigSwede]

OK, well I have ARB selectable diff lockers in my off road truck...none of this half-assed "limited slip" stuff, so there! :lol:

 

[bmorton]

A true limited slip differential does work "automatically", and hence it's not changing the definition sufficiently.

Without putting too fine a point on it, whether or not you think it's sufficient to change the meaning isn't the litmus test for deception. Again, a better argument would have to be put forward based on whether or not a reasonable person would be misled by Toyota's use of "limited slip differential" in this context. I certainly wouldn't be, no more than I was misled by VW's use of "electronic differential lock" on my last VW. I hope you wouldn't be either. Toyota's use of the "auto" word certainly would make me investigate further if I cared about that feature.

Maybe there's some subtle differences, but the concept of operation between the Camry and RAV4 are the same. Open differential plus traction control / ABS to control wheelspin. On the Camry it's just VSC/TRAC, but on the RAV now you have a "Limited Slip Differential".

Seems pretty clear from the information available that although the RAV4 and Camry both have VSC & TRAC, on the RAV4 the "Auto LSD" is a further function of TRAC that's intended to be used differently, as noted above, and is activated manually by the driver. I would draw a parallel example between the Matrix AWD and the RAV4. Although both use the same AWD system, the Matrix isn't equipped with the "Lock" button on the dash, which allows the RAV4's AWD system to be put into a mode unavailable on the Matrix. Auto LSD is also offered on the Tundra, Tacoma, 4Runner and FJ Cruiser. I'm not aware of any Toyota car that has it.

If it says on the damned spec sheets that something has a "Limited Slip Differential" (auto or not), then I fully expect that the car will have a real hardware based internally limited slip differential, as that's generically what the term has come to mean. You can't be guilty of not doing enough research when Toyota is lying right out their ass on this, and assuming that their customers will be stupid enough to not know the difference. Any case brought wouldn't necessarily have to come to trial. Things like these are commonly settled out of court just to keep things quiet and avoid all of the bad publicity and embarassment.

It all hinges on whether your expectation is a reasonable one, based on Toyota's description and information available. Toyota is clearly using "Auto LSD" as their name for what's generically widely known as an electronic LSD. "Fake traction control-based simulated LSD" doesn't quite have the same ring to it to the ears of a marketing department.

So we all agree it's not a real LSD. Whether Toyota's name for it is merely potentially confusing or a blatant, shameless bald-faced lie is entirely a matter of opinion. But hey, that's where the courts come in, isn't it? 8)