A Tesla Model Y engineer, who suggested the heat pump’s inclusion, has left the company after ten years, his LinkedIn account said.
Joseph Mardall served as the Engineering Director for Tesla from April 2018 to January 2021 but has held several other roles with the electric automaker since joining the company in February 2011 as a Senior Thermal Engineer.
Arguably, Mardall’s largest accomplishment while working with Tesla was the groundbreaking Model Y heat pump, a system that was included in the all-electric crossover to handle cold temperatures and combat range loss due to winter climates. Mardall led three teams with 60 or more engineers responsible for developing new HVAC systems that would be compatible with electric vehicles. One solution was the heat pump, an idea that came from Mardall’s engineering teams and has been a big hit with proven success in the Model Y.
CEO Elon Musk even told Teslarati in March 2020 that the heat pump was “some of the best engineering I’ve seen in a while. Team did next-level work.”
Model Y heat pump is some of the best engineering I’ve seen in a while. Team did next-level work.
— Elon Musk (@elonmusk) March 23, 2020
Mardall is headed to Zipline as the Head of Engineering. He will be working with a team of engineers “to design and build the next generation of autonomous drones to provide every human on Earth with instant access to vital medical supplies,” his LinkedIn account says. He states that the highlights of his career at Tesla “included the ground breaking Model Y Heat Pump system and leading Tesla’s efforts to develop a ventilator.”
“After 10 wonderful years at Tesla, I’m super excited to start my next chapter as Head of Engineering at Zipline, working with a team of talented and committed engineers to provide every human on Earth with instant access to vital medical supplies. The next 5 years are going to change everything, and I can’t wait! We are hiring for all roles across engineering and I would love to hear from you – come fly with me!”
Interestingly, Mardall has some medical equipment development experience, even though his work before Tesla was at McLaren Racing. Mardall worked intensively on the Tesla ventilator developed by company engineers last year. As the COVID-19 pandemic raged on, Tesla was donating third-party ventilators to hospitals in need but decided to develop its own. The ventilator prototype that Tesla built was comprised completely of parts from the Model 3 sedan, including the dash screen to see measurements of patient vitals. Mardall was present in Tesla’s video of the ventilator, posted in April 2020.
Mardall is seen here explaining the Tesla Ventilator, which was never released by the automaker. (Credit: Tesla)
It is unclear who Tesla will place in the Engineering Director Role currently. Mardall’s work at Tesla was innovative and crucial, and many Model Y (and Model 3 Refresh) owners will thank him every day for the duration of their ownership!
Tesla has scheduled its Earnings Call for Q4 and Full Year 2025 for next Wednesday, January 28, at 5:30 p.m. EST, and investors are already preparing to get some answers from executives regarding a wide variety of topics.
The company accepts several questions from retail investors through the platform Say, which then allows shareholders to vote on the best questions.
Tesla does not answer anything regarding future product releases, but they are willing to shed light on current timelines, progress of certain projects, and other plans.
There are five questions that range over a variety of topics, including SpaceX, Full Self-Driving, Robotaxi, and Optimus, which are currently in the lead to be asked and potentially answered by Elon Musk and other Tesla executives:
- You once said: Loyalty deserves loyalty. Will long-term Tesla shareholders still be prioritized if SpaceX does an IPO?
- Our Take – With a lot of speculation regarding an incoming SpaceX IPO, Tesla investors, especially long-term ones, should be able to benefit from an early opportunity to purchase shares. This has been discussed endlessly over the past year, and we must be getting close to it.
- When is FSD going to be 100% unsupervised?
- Our Take – Musk said today that this is essentially a solved problem, and it could be available in the U.S. by the end of this year.
- What is the current bottleneck to increase Robotaxi deployment & personal use unsupervised FSD? The safety/performance of the most recent models or people to monitor robots, robotaxis, in-car, or remotely? Or something else?
- Our Take – The bottleneck seems to be based on data, which Musk said Tesla needs 10 billion miles of data to achieve unsupervised FSD. Once that happens, regulatory issues will be what hold things up from moving forward.
- Regarding Optimus, could you share the current number of units deployed in Tesla factories and actively performing production tasks? What specific roles or operations are they handling, and how has their integration impacted factory efficiency or output?
- Our Take – Optimus is going to have a larger role in factories moving forward, and later this year, they will have larger responsibilities.
- Can you please tie purchased FSD to our owner accounts vs. locked to the car? This will help us enjoy it in any Tesla we drive/buy and reward us for hanging in so long, some of us since 2017.
- Our Take – This is a good one and should get us some additional information on the FSD transfer plans and Subscription-only model that Tesla will adopt soon.
Tesla will have its Earnings Call on Wednesday, January 28.
Elon Musk shared an incredible detail about Tesla Cybercab’s potential efficiency, as the company has hinted in the past that it could be one of the most affordable vehicles to operate from a per-mile basis.
ARK Invest released a report recently that shed some light on the potential incremental cost per mile of various Robotaxis that will be available on the market in the coming years.
The Cybercab, which is detailed for the year 2030, has an exceptionally low cost of operation, which is something Tesla revealed when it unveiled the vehicle a year and a half ago at the “We, Robot” event in Los Angeles.
Musk said on numerous occasions that Tesla plans to hit the $0.20 cents per mile mark with the Cybercab, describing a “clear path” to achieving that figure and emphasizing it is the “full considered” cost, which would include energy, maintenance, cleaning, depreciation, and insurance.
Probably true
— Elon Musk (@elonmusk) January 22, 2026
ARK’s report showed that the Cybercab would be roughly half the cost of the Waymo 6th Gen Robotaxi in 2030, as that would come in at around $0.40 per mile all in. Cybercab, at scale, would be at $0.20.
Credit: ARK Invest
This would be a dramatic decrease in the cost of operation for Tesla, and the savings would then be passed on to customers who choose to utilize the ride-sharing service for their own transportation needs.
The U.S. average cost of new vehicle ownership is about $0.77 per mile, according to AAA. Meanwhile, Uber and Lyft rideshares often cost between $1 and $4 per mile, while Waymo can cost between $0.60 and $1 or more per mile, according to some estimates.
Tesla’s engineering has been the true driver of these cost efficiencies, and its focus on creating a vehicle that is as cost-effective to operate as possible is truly going to pay off as the vehicle begins to scale. Tesla wants to get the Cybercab to about 5.5-6 miles per kWh, which has been discussed with prototypes.
Additionally, fewer parts due to the umboxed manufacturing process, a lower initial cost, and eliminating the need to pay humans for their labor would also contribute to a cheaper operational cost overall. While aspirational, all of the ingredients for this to be a real goal are there.
It may take some time as Tesla needs to hammer the manufacturing processes, and Musk has said there will be growing pains early. This week, he said regarding the early production efforts:
“…initial production is always very slow and follows an S-curve. The speed of production ramp is inversely proportionate to how many new parts and steps there are. For Cybercab and Optimus, almost everything is new, so the early production rate will be agonizingly slow, but eventually end up being insanely fast.”
Elon Musk
Elon Musk to attend 2026 World Economic Forum at Davos
The Tesla CEO was confirmed as a last-minute speaker for a session with BlackRock CEO Larry Fink.
Elon Musk is poised to attend the 2026 World Economic Forum in Davos. The Tesla CEO was confirmed as a last-minute speaker for a session with BlackRock CEO Larry Fink, signaling a thaw in Musk’s long-strained relationship with the event.
A late addition
Organizers of the World Economic Forum confirmed that Elon Musk was added shortly before the event to a Thursday afternoon session, where he was scheduled to speak with Fink, as noted in a Bloomberg News report. Musk’s upcoming appearance marks Musk’s first participation in the forum, which annually draws political leaders, business executives, and global media to Davos, Switzerland.
Musk’s attendance represents a departure from his past stance toward the event. He had been invited in prior years but declined to attend, including in 2024. His upcoming appearance followed remarks from his political ally, Donald Trump, who addressed the forum earlier in the week with a wide-ranging speech.
A previously strained relationship
Musk had frequently criticized the World Economic Forum in the past, describing it as elitist and questioning its influence. In earlier posts, he characterized the gathering as “boring” and accused it of functioning like an unelected global authority. Those remarks contributed to a long-running distance between Musk and WEF organizers.
The forum previously said Musk had not been invited since 2015, though that position has since shifted. Organizers indicated last year that Musk was welcome amid heightened interest in his political and business activities, including his involvement in the Trump administration’s Department of Government Efficiency (DOGE). Musk later stepped away from that role.
Despite his friction with the World Economic Forum, Musk has remained central to several global events, from SpaceX’s provision of satellite internet services in geopolitically sensitive regions through Starlink to the growing use of xAI’s Grok in U.S. government applications.
Tesla Earnings Call: Top 5 questions investors are asking
Elon Musk shares incredible detail about Tesla Cybercab efficiency
