Tesla Model S
How does the Tesla Model S Traction Control system work?
I was pulling out of the parking lot at work the other day and happened to experience some wheel spin as I drove over a patch of sand near a construction site. One wheel spun with limited grip while the other wheel pushed me through the slippery patch. The wheel modulation happened automatically and trouble free which led me to think – How does the Model S traction control work?
Before I dive into it all, one caveat: I’m an electrical/software engineer and not a mechanical engineer. I can change a tire, I used to change my own oil many years ago, but otherwise I let a trusted shop (usually a dealer) do all of the work. The information below is based on my own research and opinions.
Open Differential
I had a very basic knowledge of how the AC induction motor drives the wheels on my Model S. I thought it was just a direct current motor with a positive and negative terminal that spun one way or the other depending on polarity which in turn spun the wheels. This kind of thinking comes from my days dealing with radio control hobby kits coming out of Radio Shack. I hadn’t thought about how that may translate into driving of two wheels, nor how it would handle situations where traction is limited due to sand and ice.
It turns out, the shaft of the Model S electric motor inserts into an open differential gear box that then drives the two wheels. This gearing allows the outside drive wheel to rotate faster than the inner drive wheel during turns. Without this gearing either the inside wheel will rotate too fast or the outside wheel will drag. Any imbalance may lead to poor handling, damage to your tires and introduce a lot of stress to the drivetrain. HowStuffWorks has great animated images showing how it operates in action.
Tesla describes the gearing as follows (for the Roadster):
“The motor is directly coupled to a single speed gearbox, above the rear axle. The simplicity of a single gear ratio reduces weight and eliminates the need for complicated shifting and clutch work. The elegant motor does not need a complicated reverse gear – the motor simply spins in the opposite direction.”
The downside of the open differential approach is that torque is evenly applied to both wheels. The traction control system limits the maximum amount of torque that can be applied to each wheel without making it slip.
Turning traction control off essentially allows the motor to not back down even when one of the tires is spinning. This can often result in a lot of tire spinning and will not necessarily remove you from being stuck. In fact you may end up digging a deeper hole than the one you’re already in.
Limited Slip
Traditionally a limited slip differential allows for torque to be applied independently of each wheel. This involves complicated gearing which involves more components, adds additional weight and overall may not be as reliable on a Model S that produces such astronomical torque. For that reason Tesla chose to utilize a much simpler and sturdier open differential. But they needed to solve the slip problem.
Tesla solved the problem on the Model S by selectively applying rear brakes in order to transfer torque to the wheel that grips. These commands are fed into the electronic stability control system which is capable of braking the rear wheels independently as a way to improve the handling of the car under various conditions.
Tesla describes both traction and stability control as follows:
“Model S Traction Control is designed to ensure maximum contact between the road and the tires. Whether you are accelerating off the line, zooming along the winding roads of the Rockies or find yourself in a Gulf Coast rainstorm, Traction Control prevents loss of traction and maintains control. Stability Control reacts in moments of under-steer or over-steer by reducing torque and applying the brakes to individual wheels for enhanced control when cornering.”
Summary
Tesla Motors is about disrupting the norm and re-thinking how things should be done. If you start from scratch and question every design decision, every part, every ounce of weight, every approach and leverage the best minds on the planet, what kind of car will you end up with? The Model S is Tesla’s current answer and certainly not their final answer.
Tesla’s traction control and emulated limited slip functionality is another case of Tesla replacing complex and inefficient hardware with something lighter, simpler and more state of the art – augmenting functionality through software and algorithmic science utilizing today’s advanced computing power.
The next time you slam that “go” pedal and take off like a space ship, think about all the technology that’s helping you launch into the future.
News
Tesla makes latest move to remove Model S and Model X from its lineup
Tesla’s latest decisive step toward phasing out its flagship sedan and SUV was quietly removing the Model S and Model X from its U.S. referral program earlier this week.
Tesla has made its latest move that indicates the Model S and Model X are being removed from the company’s lineup, an action that was confirmed by the company earlier this quarter, that the two flagship vehicles would no longer be produced.
Tesla has ultimately started phasing out the Model S and Model X in several ways, as it recently indicated it had sold out of a paint color for the two vehicles.
Now, the company is making even more moves that show its plans for the two vehicles are being eliminated slowly but surely.
Tesla’s latest decisive step toward phasing out its flagship sedan and SUV was quietly removing the Model S and Model X from its U.S. referral program earlier this week.
The change eliminates the $1,000 referral discount previously available to new buyers of these vehicles. Existing Tesla owners purchasing a new Model S or Model X will now only receive a halved loyalty discount of $500, down from $1,000.
The updates extend beyond the two flagship vehicles. New Cybertruck buyers using a referral code on Premium AWD or Cyberbeast configurations will no longer get $1,000 off. Instead, both referrer and buyer receive three months of Full Self-Driving (Supervised).
The loyalty discount for Cybertruck purchases, excluding the new Dual Motor AWD trim level, has also been cut to $500.
NEWS: Tesla has removed the Model S and Model X from the referral program.
New owners also no longer get a $1,000 referral discount on a new Cybertruck Premium AWD or Cyberbeast. Instead, you now get 3 months of FSD (Supervised).
Additionally, Tesla has reduced the loyalty… pic.twitter.com/IgIY8Hi2WJ
— Sawyer Merritt (@SawyerMerritt) March 6, 2026
These adjustments apply only in the United States, and reflect Tesla’s broader strategy to optimize margins while boosting adoption of its autonomous driving software.
The timing is no coincidence. Tesla confirmed earlier this year that Model S and Model X production will end in the second quarter of 2026, roughly June, as the company reallocates factory capacity toward its Optimus humanoid robot and next-generation vehicles.
With annual sales of the low-volume flagships already declining (just 53,900 units in 2025), incentives are no longer needed to drive demand. Production is winding down, and Tesla expects strong remaining interest without subsidies.
Industry observers see this as the clearest sign yet of an “end-of-life” phase for the vehicles that once defined Tesla’s luxury segment. Community reactions on X range from nostalgia, “Rest in power S and X”, to frustration among long-time owners who feel perks are eroding just as the models approach discontinuation.
Some buyers are rushing orders to lock in final discounts before they vanish entirely.
Doug DeMuro names Tesla Model S the Most Important Car of the last 30 years
For Tesla, the move prioritizes efficiency: fewer discounts on outgoing models, a stronger push for FSD subscriptions, and a focus on high-margin Cybertruck trims amid surging orders.
Loyalists still have a narrow window to purchase a refreshed Plaid or Long Range model with remaining incentives, but the message is clear: Tesla’s lineup is evolving, and the era of the original flagships is drawing to a close.
News
Tesla Model S and X customization options begin to thin as their closure nears
Tesla’s Online Design Studio for both vehicles now shows the first color option to be listed as “Sold Out,” as Lunar Silver is officially no longer available for the Model S or Model X. This color is exclusive to these cars and not available on the Model S or Model X.
Tesla Model S and Model X customization options are beginning to thin for the first time as the closure of the two “sentimental” vehicles nears.
We are officially seeing the first options disappear as Tesla begins to work toward ending production of the two cars and the options that are available to those vehicles specifically.
Tesla’s Online Design Studio for both vehicles now shows the first color option to be listed as “Sold Out,” as Lunar Silver is officially no longer available for the Model S or Model X. This color is exclusive to these cars and not available on the Model S or Model X.
🚨 Tesla Model S and Model X availability is thinning, as Tesla has officially shown that the Lunar Silver color option on both vehicles is officially sold out
To be fair, Frost Blue is still available so no need to freak out pic.twitter.com/YnwsDbsFOv
— TESLARATI (@Teslarati) February 25, 2026
Tesla is making way for the Optimus humanoid robot project at the Fremont Factory, where the Model S and Model X are produced. The two cars are low-volume models and do not contribute more than a few percent to Tesla’s yearly delivery figures.
With CEO Elon Musk confirming that the Model S and Model X would officially be phased out at the end of the quarter, some of the options are being thinned out.
This is an expected move considering Tesla’s plans for the two vehicles, as it will make for an easier process of transitioning that portion of the Fremont plant to cater to Optimus manufacturing. Additionally, this is likely one of the least popular colors, and Tesla is choosing to only keep around what it is seeing routine demand for.
During the Q4 Earnings Call in January, Musk confirmed the end of the Model S and Model X:
“It is time to bring the Model S and Model X programs to an end with an honorable discharge. It is time to bring the S/X programs to an end. It’s part of our overall shift to an autonomous future.”
Fremont will now build one million Optimus units per year as production is ramped.
Tesla is bringing closure to its flagship Model S and Model X vehicles, which CEO Elon Musk said several years ago were only produced for “sentimental reasons.”
The Model S and Model X have been light contributors to Tesla’s delivery growth over the past few years, commonly contributing only a few percentage points toward the over 1.7 million cars the company has handed over to customers annually since 2022.
However, the Model S and Model X have remained in production because of their high-end performance and flagship status; they are truly two vehicles that are premium offerings and do not hold major weight toward Tesla’s future goals.
On Wednesday, during the Q4 2025 Earnings Call, Musk confirmed that Tesla would bring closure to the two models, ending their production and making way for the manufacturing efforts of the Optimus robot:
“It is time to bring the Model S and Model X programs to an end with an honorable discharge. It is time to bring the S/X programs to an end. It’s part of our overall shift to an autonomous future.”
Musk said the production lines that Tesla has for the Model S and Model X at the Fremont Factory in Northern California will be transitioned to Optimus production lines that will produce one million units per year.
Tesla Fremont Factory celebrates 15 years of electric vehicle production
Tesla will continue to service Model S and Model X vehicles, but it will officially stop deliveries of the cars in Q2, as inventory will be liquidated. When they’re gone, they’re gone.
BREAKING: Tesla will wind down Model S and Model X production next quarter, Elon Musk confirms.
“It is time to bring the Model S and Model X programs to an end with an honorable discharge.” pic.twitter.com/Czn7aQjJE1
— TESLARATI (@Teslarati) January 28, 2026
Tesla has been making moves to sunset the two vehicles for the better part of one year. Last July, it stopped taking any custom orders for vehicles in Europe, essentially pushing the idea that the program was coming to a close soon.
Musk said back in 2019:
“I mean, they’re very expensive, made in low volume. To be totally frank, we’re continuing to make them more for sentimental reasons than anything else. They’re really of minor importance to the future.”
That point is more relevant than ever as Tesla is ending the production of the cars to make way for Optimus, which will likely be Tesla’s biggest product in the coming years.
Musk added during the Earnings Call on Wednesday that he believes Optimus will be a major needle-mover of the United States’ GDP, as it will increase productivity and enable universal high income for humans.
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