Lifestyle
Charging a Tesla Model S Might Be Costing More Than You Think

When you fill up a normal ICE car you know exactly what your costs are for the fuel. With an electric vehicle it is not that simple. There is a charging efficiency factor that comes into play which means that the reported amount of energy used could be understated and lower than the actual energy used. In a previous post I wrote about installing an EKM Digital Submeter on my NEMA 14-50 outlet to measure actual power usage of the Model S against the reported power displayed on the driver’s digital dash display. A month later and armed with more data, the energy loss I’m seeing is larger than I had originally expected.
Test Setup
I charge at home 99% of the time and in the last three months I’ve logged 7,500+ miles driven, one trip to the Supercharger and two visits to the Tesla store’s High Power Wall Connector. I have a professionally installed NEMA 14-50 outlet at home. I’m using the factory supplied Universal Mobile Connector (UMC) as the cable between the outlet and the car. An EKM digital sub meter measures actual draw from the outlet and is accurate to within 1% and does not add any measurable load of its own.
Methodology
On the “anniversary date” of taking delivery of my Model S I recorded all of the pertinent info that was displayed before resetting the Trip A meter. Before driving the next day I record the reading on the EKM meter. That way I’ve got the mileage and the Tesla reported power usage over the period driven. This process will let me see a bunch of information that I plan on tracking over time, as follows:
- Monthly miles driven
- Monthly kWh used as reported by the Model S
- Monthly kWh used as reported by the EKM meter
- Monthly Average energy used
I plan on using this information to look at how average energy used changes as the months/temperature changes and perhaps as the Model S gets more miles on it. While I don’t drive consistently on any given day (test drives, special trips and the like), the numbers will average out and my driving style is not likely to change much after 30 years of driving (yeah I’m getting old but the Model S makes me feel young again!). I also drive pretty consistent patterns of commuting with a lot of miles to the same places which helps average out the special trips to locations with different terrain/conditions. Basically, while the conditions aren’t perfectly stable over time, the averages and data from this real world testing will be pretty accurate.
The Data
The last period (6/21 – 7/21) was my first full period with both the car and the EKM meter. A month of driving and charging, especially with the miles and kWh’s involved is a decent period over which to look at the results versus the 2 days from my prior blog post. Here’s the data: In the above table you can see that the Model S reported 728 kWh used during the period but the meter reported 894 kWh used. This means my charging efficiency is only about 82% and electric usage (and cost) is 23% higher than I may have expected based on the readings the Model S provides. For that month this is an extra $26 of charging cost which is a small number but a notable percentage of the total. The good news is that even using this larger kWh number, the savings versus driving my old ICE car for energy alone comes in at $334 — I’m saving $334/month in gas driving my Model S!
Summary
Research suggests that an average charging efficiency loss ranges between 10-12%. Over this one month period of over 2,400 miles I'm seeing an 23% loss using the standard home charging setup that Tesla recommends. Many people quote an 85% charge efficiency for Tesla, and Tesla's own charging calculator appears to assume a 91% charging efficiency which is quite different than the 82% actual charge efficiency I've measured and significantly worse than the average industry charging efficiency. It would be great to see another Model S owner do a similar test using the HPWC setup at home and see if they get results similar to what Tesla is providing. I'd love to do the test but I'm not quite ready to shell out $1,200 plus electrician costs to get that data -- assuming a cost of about $3,000 all in it would take me over 20 years to break even assuming the HPWC improves my efficiency by 10%. From the results above, my conclusion is that the Model S charging efficiency using the standard home setup is 5-10% worse than other EVs on the market.
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Lifestyle
Tesla brings perhaps the coolest interior feature to cars in latest update
Tesla adds on to the “fun” aspect of its vehicles.

Tesla has brought perhaps the coolest interior feature to its cars in a new update that is rolling out to vehicles now.
The feature will require a newer vehicle that has interior ambient lighting, which is present on the new Model S, Model X, Model 3 “Highland,” and Model Y “Juniper.” The Cybertruck also has ambient lighting strips throughout.
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With the Version 2025.26+ Software Update, Tesla is rolling out a new “Sync Accent Lights w/ Music” feature, which is available on the Tesla Toybox:
Turn your Tesla into a rave cave with the new Light Sync feature 🎶
Rolling out now in software update 2025.26+ pic.twitter.com/IIsQxZ9jDP
— Tesla (@Tesla) July 29, 2025
To enable the feature, you’ll access the Toybox, choose “Light Sync,” and then choose “Sync Accent Lights w/ Music.”
Although it does not improve the performance of the vehicle, it is yet another example of Tesla making one of the coolest cars out there. This is truly a cool add-on that can be used to impress your friends and family.
Elon Musk
xAI, Musk Foundation helps schools near Memphis supercomputer site
Reports of xAI and the Musk Foundation’s work were recently posted by local news media.

Elon Musk’s artificial intelligence startup xAI and the Musk Foundation have been supporting Memphis-Shelby County Schools with HVAC repairs and facility upgrades, while also funding youth programs for students in the area.
Reports of xAI and the Musk Foundation’s work were recently posted by local news media.
xAI’s school visits lead to facility repairs
Representatives from xAI visited John P. Freeman Optional School, Fairley High School, and Westwood High School, all of which are located near its Colossus supercomputer site, to assess HVAC systems, plumbing, gym facilities, and athletic fields. The visits resulted in a list of priority repairs, some of which were completed in April and May.
In addition to the repairs, xAI also shared a number of initiatives that are planned for students in the area, as stated in a Commercial Appeal report.
“xAI is working on providing STEM workshops for local students, donating equipment to technical training programs, and supporting job fairs to boost employment opportunities. These initiatives reflect xAl’s commitment to fostering education and economic growth in Memphis,” xAI noted in a statement.
Musk Foundation donation
Apart from xAI, the Musk Foundation also donated $350,000 to the Boys & Girls Clubs of Greater Memphis, enabling the reopening of two club sites located at Booker T. Washington High School and Westwood High School. Both locations had closed earlier this year due to lapses in funding. As per xAI, the Musk Foundation’s donation allows clubs to reopen for almost 1,000 students.
The donation will fund staffing, supplies, and transportation, among others. “Kids are the future of humanity,” Elon Musk said in a statement, adding that students need “every chance to shoot for the stars.”
“We’re honored to support the Boys & Girls Clubs of Greater Memphis in reopening these sites, giving kids in underserved communities the tools to build brighter futures,” Musk said.
The gift was praised by local officials, including Boys & Girls Clubs board chair Michael Garriga, who stated that the “commitment will ensure the youth of our community have the opportunities they need to develop their skills and talents to become successful students and future citizens.”
Lifestyle
EV fans urge Tesla to acquire Unplugged Performance for edge in fleet and security industry
Unplugged Performance has built a name for itself by producing performance upgrades for Tesla vehicles.

A growing number of Tesla enthusiasts and longtime community voices are calling on the electric vehicle maker to acquire Unplugged Performance, a California-based aftermarket company best known for tuning Tesla vehicles and developing specialized government fleet solutions under its UP.FIT division.
The idea was once considered a niche proposal among EV fans, but it is now gaining serious attention not just as a performance play but as a strategic move to deepen Tesla’s roots in the fleet and security industry.
A strategic fit
Unplugged Performance has built a name for itself by producing performance upgrades for Tesla vehicles, from track-optimized components to visual and aerodynamic upgrades. But in recent years, its UP.FIT division has pivoted toward a more functional future by outfitting Tesla vehicles like Model Ys for police, military, and government use.
That work has sparked growing calls for closer collaboration with Tesla, especially as the EV maker increasingly leans into autonomy, AI, and fleet services as core components of its next chapter.
“I posted this four years ago, but I think it’s more true now than ever,” wrote Whole Mars Catalog, a well-known Tesla investor and FSD Beta tester, on X. “Tesla should buy Unplugged. But not just as a Performance division. What they are doing with UP.FIT unlocks large government and commercial fleet purchases that can improve utilization.”
Tesla fans such as shareholder Sawyer Merritt echoed the sentiment, calling Unplugged a “great fit within Tesla.” adding, “They are literally located directly next to Tesla’s design studio in Hawthorne.”
Enabling the next wave
Supporters of the idea noted that integrating Unplugged into Tesla’s corporate structure could help accelerate the adoption of autonomous technologies in government sectors. With UP.FIT patrol cars already in use across some U.S. police departments, Tesla fans envisioned a future where self-driving Teslas could potentially revolutionize law enforcement, search-and-rescue, and public service logistics.
“Just imagine how autonomous patrol cars could transform policing and bring us into a safer future,” the veteran FSD tester wrote.
The benefits could also extend to Tesla’s existing consumer base. “They also have some incredible products in the works that I think will appeal to many ordinary Tesla drivers — not just those looking for performance or mods. Stuff that’s so good it should have come straight from the design studio next door,” Whole Mars Catalog noted.
Unplugged Performance, founded in 2013, shares not just a product vision with Tesla, but also geography. Its Hawthorne headquarters sits directly adjacent to Tesla’s design studio, and the two companies have maintained a close working relationship over the years. The aftermarket firm has long positioned itself as a “mission-aligned” partner to Tesla.
In response to the recent calls for acquisition, Unplugged Performance acknowledged the support from the community. “Our very existence is to support the Tesla mission with @UpfitTesla and @UnpluggedTesla,” Unplugged CEO Ben Schaffer posted on X. “We love working with Tesla and are grateful for the community’s support since 2013!”
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