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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Elon Musk
The Boring Company just doubled its tunneling power in Nashville
The Boring Company’s Prufrock MB2 is commissioned and ready to mine beneath Nashville’s streets.
The Boring Company’s second tunnel boring machine, Prufrock MB2, is officially ready to dig in Nashville. The company confirmed the news on X, posting: “Prufrock-MB2 is ready to mine in Nashville! MB2 commissioning is complete, including the brief 11 rpm rotation shown here. Will MB2 catch up to MB1, who had quite the head start? And Prufrock-MB3 ships in August!”
MB2 arrives with meaningful improvements over its predecessor. Lessons learned from the launch and operation of MB1 have already been applied to MB2 to improve efficiency and prepare the machine for launch.
Traditional tunnel boring machines operate in a stop-and-go cycle, digging roughly five feet, halt, erect precast concrete segments to line the tunnel wall, then resume. That repeated interruption is one of the main reasons conventional tunneling is slow and expensive. Prufrock is designed to install the tunnel liner simultaneously with mining, eliminating the need to stop every five feet. The machine also skips the need for excavated launch pits. Prufrock arrives on a truck, tilts down, and launches into the ground within 24 hours. And when the tunnel is complete, it emerges from the ground and drives to its next launch site on a trailer, eliminating the need for expensive cranes or pit excavation. The machine is also fully electric and runs with zero people in the tunnel during normal operations, controlled remotely from a surface operations center.
Prufrock-MB2 is ready to mine in Nashville! MB2 commissioning is complete, including the brief 11 rpm rotation shown here.
Will MB2 catch up to MB1, who had quite the head start?
And Prufrock-MB3 ships in August! pic.twitter.com/TTrMql2aRg
— The Boring Company (@boringcompany) June 17, 2026
It won’t be long before we hear of another major update on The Boring Company’s Music City Loop project – a planned underground transit network beneath Nashville that would move passengers in electric vehicles through a series of tunnels at highway speeds, and bypassing surface traffic entirely. Nashville was selected in part because of its strong rock conditions that suits the Prufrock machines well, and relatively less regulatory hurdles.
Progress has been steady on multiple fronts. All 37 permits and approvals required ahead of tunneling have been obtained, out of 45 total. Key wins include a fully executed TDOT tunnel permit authorizing 25 miles of tunnel, unanimous airport authority approval for a Nashville International Airport station, and the city’s first residential station agreement serving downtown tower residents.
With MB1 already tunneling, MB2 now commissioned, and MB3 shipping in August, Nashville is becoming something of a live proving ground for scaled tunnel boring. The broader ambition is not limited to one city. The Boring Company’s stated goal is to make underground transportation a practical alternative to surface roads across major metro areas. Nashville is one of many cities, including a successful Las Vegas tunnel system, where that idea is being put to the test at real speed.
Investor's Corner
Tesla unfolded its first European “folding Supercharger”
Tesla’s folding Supercharger just arrived in Europe and it changes how fast charging expands.
Tesla’s Folding Unit Supercharger has officially landed in Europe, with the company teasing a new installation in its effort for a broader rollout targeting major motorway rest stops across the European continent in Q3 2026. The arrival marks a notable shift in how Tesla is thinking about network expansion, moving from hardware performance alone to engineering the logistics chain itself.
While Tesla did not reveal the exact location for the new folding Supercharger in Europe, the photo shared on X heavily suggests that this maybe somewhere in Norway. Historically, whenever Tesla rolls out an entirely new infrastructure architecture in Europe, whether it was the original Supercharger stalls years ago or these brand-new modular V4 “Folding Units”, Norway is almost always the designated launch pad because of its unmatched EV adoption rate and supportive infrastructure
The Folding Unit, introduced in March 2026, is a factory pre-assembled V4 charging station built on an industrial hinge system mounted to a heavy-duty concrete base. The entire assembly arrives on site ready to unfold and connect. Tesla confirmed the units feature telescopic light poles specifically designed for easy transportation and fast on-site deployment, a detail that signals how carefully the logistics chain has been engineered alongside the hardware itself. The design allows 33% more stalls per delivery truck, cuts installation time roughly in half, and reduces overall deployment costs by more than 20% compared to traditional installations.
Tesla’s newest “Folding V4 Superchargers” are key to its most aggressive expansion yet
Tesla also noted telescopic light poles which provide benefits over traditional Supercharger installations that require fixed-height poles that are awkward to ship, slow to position on site, and often require separate crews and equipment to erect before charging hardware can even be staged. By engineering poles that compress for transit and extend on arrival, Tesla has removed one of the quieter bottlenecks in the physical deployment process. Every hour saved on a light pole installation is an hour redirected toward getting stalls energized. At scale, across dozens of new sites per quarter, those hours add up to a meaningful acceleration in how quickly a location goes from approved permit to serving its first customer.
Each Folding Unit pairs a single V4 power cabinet with eight charging posts. The V4 cabinet delivers up to 500 kW per stall for passenger vehicles and up to 1.2 MW for the Tesla Semi, supporting twice the stalls per cabinet at three times the power density of its predecessor. Longer cables make every new station immediately usable by non-Tesla vehicles, a priority as Tesla continues opening its network to Ford, GM, Rivian, Hyundai, Stellantis, and others.
As Teslarati reported when the Folding Unit was first unveiled, Tesla’s Gigafactory New York produced its final V3 Supercharger cabinet in March 2026 after more than seven years and 15,000 units, completing a full pivot to V4 production. The European arrival of the folding design is the next chapter in that transition.
Faster and cheaper deployment means Tesla can justify building in markets and corridors that were previously too expensive to serve, filling the coverage gaps that have slowed EV adoption outside major urban centers.
First Folding Unit Superchargers in Europe 🇪🇺 https://t.co/KNfYWJukkL pic.twitter.com/YR1udIpH1i
— Tesla Charging (@TeslaCharging) June 10, 2026
Elon Musk
SpaceXAI just launched into your kitchen with their new app
SpaceXAI just powered its first consumer app and it predicts what you want to buy.
SpaceXAI just made its first move into consumer AI, and it involves your grocery cart. On June 3, 2026, Gopuff and SpaceXAI announced the launch of Go, a Grok-powered shopping assistant built directly into the Gopuff app that predicts what you need before you even start searching for it.
Gopuff is an instant delivery platform that operates more than 400 micro-fulfillment centers across the U.S., delivering everyday essentials, snacks, drinks, and household items in as little as 15 minutes. It is not a restaurant delivery app or a marketplace. It owns its inventory, controls its warehouses, and handles its own logistics, which means it has built one of the most detailed consumer behavior datasets in retail over its 13-year history.
Go combines SpaceXAI’s advanced reasoning, voice, and image generation models with Gopuff’s dataset of hundreds of millions of orders and real-time cultural signals from X to prepare a suggested cart the moment a customer opens the app. It learns each shopper’s habits and automatically builds a personalized cart based on time of day, location, order history, and real-time indicators. Returning customers can check out with a single tap.
Rather than searching for specific items, users can describe a situation like a game-day party or the desire for a healthy breakfast and Go will assemble a cart automatically. It can also predict when shoppers are running low on items like coffee or paper towels and have them packed and delivered in under 15 minutes. Grok voice integration lets users talk to the app in plain conversational language and check out completely hands-free.
Gopuff co-founder and co-CEO Yakir Gola said: “Today, we believe the greatest friction left in commerce is not delivery or instantaneous access to the essentials customers need. It’s the moment before: the thinking, the deciding, the remembering. We’re combining Gopuff’s demand intelligence with xAI’s frontier reasoning to create an everyday shopping experience that feels like a true extension of you.”
Why SpaceX just made a $60 billion bet on AI coding ahead of historic IPO
The timing carries context beyond the product launch. SpaceXAI was formed after SpaceX completed an all-stock merger with Elon Musk’s xAI earlier this year, folding one of the most advanced AI labs in the world into the same corporate structure as the company preparing what could be the largest IPO in history. SpaceXAI is dipping into consumer-focused AI just as it prepares for its public debut, and while Musk has openly discussed building an everything app, this launch uses Grok to power another company’s product rather than launching a standalone consumer platform. Every consumer-facing deployment of Grok ahead of the IPO roadshow adds tangible evidence that SpaceXAI is not just an infrastructure play but a direct competitor in the AI application layer where OpenAI and Google are already fighting for dominance.