There are lots of features our trucks and SUVs have that we might not properly understand, and some that we don’t even know they have until a warning light for them appears on the dash. One of those features you might not be completely sure about is Auto LSD, so what is Auto LSD, what does it do, how does it work, and do you actually need it? In this article, you will discover the ins and outs of Toyota’s Auto Limited Slip Differential (LSD) technology! Learn how it enhances traction, control, and performance in popular models like Tundra, Tacoma, RAV4, and Sequoia.
Auto LSD is short for Automatic Limited-Slip Differential, which is a Toyota traction control system that automatically controls the engine output and applies braking when it detects that one of the rear wheels is losing grip and is starting to spin. The system only operates in two-wheel drive and it does not work when four-wheel drive is engaged.
Is Auto LSD a fancy limited-slip differential?
No, the Auto LSD system is a feature on Toyota vehicles that have an open rear differential that imitates a limited-slip differential when engaged in certain situations. A regular limited-slip differential is a mechanical device that cannot be turned on and off, whereas Auto LSD is only supposed to be used in extreme conditions.
While a mechanical limited-slip differential is available and working all the time to distribute power efficiently to the rear wheel that needs it most, Auto LSD needs to be engaged. When engaged, Auto LSD will not only redistribute power to the wheel that has the most traction in the way a conventional limited-slip differential will do when one wheel is slipping, but it will also engage the brake to effectively lock the spinning wheel.
Effectively, Auto LSD works to combine the benefits of both a limited-slip differential and a locking rear differential on a vehicle that actually has an open rear differential in extreme circumstances.
Do you have to choose whether to have Auto LSD on or off?
Auto LSD is always on when a vehicle is in rear-wheel-drive mode, but there is an Auto LSD button for the driver to press that makes it work differently. Without the button pressed and therefore without the Auto LSD light showing on the dash, the feature is waiting in the background as long as the vehicle is in rear-drive mode.
If Auto LSD detects that one of the rear wheels is starting to slip it will send more drive to the wheel that has the most traction, it will apply braking to the wheel that’s slipping, but it will also limit the engine output to less than 1,000 rpm.
If the driver decided to press the Auto LSD button and the light then comes on the dash, the system will still distribute torque to the wheel with traction and brake the slipping wheel, but now there will be no limiting of the engine output. If the driver puts their foot down when the Auto LSD light is on revs will increase as much as they would normally when the gas pedal is pressed.
Can Auto LSD be turned on in four-wheel-drive mode?
Part of the “automatic” element of Auto LSD is the fact you don’t have to remember to turn it on and off as you swap between rear-drive and four-wheel-drive modes. As soon as you engage four-wheel-drive the system will turn itself off completely, and you cannot re-engage it unless you put the vehicle back into rear-wheel-drive.
Once back in rear-drive, Auto LSD will then be working in the background, but only in the way mentioned above where the engine output will be limited unless the button is pressed to put the light back on so rev-limiting is then turned off. So no, Auto LSD cannot be turned on when operating in four-wheel-drive mode.
Which Toyota vehicles have Auto LSD?
Toyota offers a variety of models equipped with the Automatic Limited Slip Differential (Auto LSD) feature. The 2023 models that include this feature are the Toyota Tundra, Toyota Tacoma, Toyota Sequoia, and RAV4.
Toyota Tundra with Auto LSD
The Tundra is a full-size pickup truck that boasts powerful performance and a spacious interior. With Auto LSD, drivers can enjoy superior traction and control, especially when driving off-road or in inclement weather conditions.
Toyota Tacoma With Auto LSD
The Tacoma is a midsize pickup truck that offers impressive off-road capabilities and a refined cabin. Auto LSD provides drivers with enhanced stability and grip when navigating uneven terrain, steep inclines, or slick surfaces.
Toyota Sequoia With Auto LSD
The Sequoia is a full-size SUV that can accommodate up to eight passengers and offers ample cargo space. With Auto LSD, drivers can confidently navigate challenging road conditions, such as snow or mud, and ensure the safety of their passengers.
Toyota RAV4 With Auto LSD
Finally, the RAV4 is a compact SUV that delivers a versatile driving experience and excellent fuel efficiency. Auto LSD enhances the RAV4’s handling and stability, providing drivers with a comfortable and secure ride.
What is Auto LSD for?
To understand how Auto LSD works, it’s important to first understand what an open differential is. An open differential is the standard type of differential found in most vehicles. It is designed to allow the wheels on the same axle to rotate at different speeds, which is necessary when turning corners. However, when one wheel loses traction, such as on a slippery surface, the differential sends power to that wheel with the least resistance, causing the wheel to spin and reducing engine performance.
This is where Auto LSD comes in. When using Auto LSD on a Toyota vehicle, the feature engages a secondary layer of computer logic in the Traction Control system. This allows for a certain amount of slip between the drive wheels, which improves traction and prevents the rear wheels from spinning.
The benefits of using Auto LSD are numerous. For one, it allows for better control of the vehicle, particularly in challenging driving conditions. Additionally, it enhances engine performance by allowing power to be distributed more efficiently to the wheels with the most traction.
Overall, the Automatic Limited Slip Differential is a valuable feature that can greatly improve a vehicle’s handling and performance. Whether driving on slippery roads or off-roading on uneven terrain, using Auto LSD on a Toyota can help drivers maintain better control of their vehicle and enjoy a safer and more comfortable driving experience.
Why have a limited-slip differential instead of Auto LSD?
Although a limited-slip differential does offer extra traction for the rear wheels of a vehicle in mud, sand, ice, or snow, that’s not an environment where the feature is usually employed. These days, it’s performance cars that have limited-slip differentials, while SUVs and trucks have all-wheel-drive and four-wheel-drive systems and locking differentials to cope with challenging terrain and surfaces.
If you want to experience a limited-slip differential in action today, you’re best looking towards the likes of a Chevy Camaro, Dodge Challenger, Ford Mustang, or even a Toyota GT86.
This is because a limited-slip differential allows each of the rear wheels to continue turning at different speeds without being locked to each other completely. Still, it can also limit the amount of torque sent to the spinning wheel while at the same time maximizing the torque sent to the wheel that has the most traction.
A limited-slip differential is best employed in performance cars like those mentioned above to give more traction when negotiating bends at speed by sending more torque to the rear wheel that has the most grip while reducing the amount sent to the wheel that has the least.
Do you need Auto LSD?
I’m not convinced that there’s any real need for Auto LSD when your vehicle is already equipped with four-wheel drive, especially when you have both high and low-range available to you. It really isn’t much of a hassle to engage four-wheel-drive, so I’m not quite sure what the point of Auto LSD is these days, especially as today’s systems are so user-friendly with setting for sorts of surfaces that reduce the need for any real expertise.
This being said, there is one clear benefit of having Auto LSD. There is one major misconception about four-wheel drive. A four-wheel drive system without some form of LSD or a true locking differential is really just a two-wheel drive system. I know this is confusing, and I almost didn’t discuss it.
You see, a four-wheel drive system puts equal power to both the front and rear axles. However, without some form of locking differential, if one rear wheel starts to spin, no traction goes to the other wheel.
The same can be said for your front axle. If one of the front wheels starts to spin, the other front wheel will not get traction either.
This is the whole point of the Auto LSD, traditional limited-slip differentials and especially true locking differentials that you would see for heavy offroad use.
The reality is for most daily drivers who may drive in the snow, on gravel roads or other inclement driving conditions, the Auto LDS will be a nice to have, but generally you may not get that much use out of it.
However, if you find yourself offroad in a lot of mud, the added traction of the Toyota lsd feature will be a welcomed feature to help get you back home.
To be honest, I’m not even sure how much AWD is required on a lot of the SUVs that have it. I have owned a Lexus GX460 for over 11 years. The GX 460 even has a center-locking differential, and I think I have used it only three or four times when in heavy snow up in the mountains.
It’s obviously a different matter if you are going off-road regularly and asking your vehicle to cope with some pretty challenging terrain. I think all-wheel-drive is most effective for performance cars or for SUVs in parts of the country where snow and ice can be a problem in winter, four-wheel-drive, and locking differentials are for proper off-roading, and a limited-slip differential is essential for rear-wheel-drive performance cars. As far as Auto LSD is concerned, it’s yet to be determined how it stacks up to these other more proven limited-slip differential and locking differential solutions.