Lifestyle
EKM Digital Submeter Measures EV Charging Efficiency
Electric vehicle owners may now know that 10-12% of drawn electricity is lost during the charging process when AC is converted to DC.
The “Since Last Charge” indicator on the Tesla Model S driver’s console keeps count of distance, energy used and average energy used per mile since the last time you unplugged, but matching this energy consumption to what you’re being billed by your company is more difficult than one might think.
Taking the 10.6kWh Total Energy readout from the dash and multiplying it by my billable electricity rate of $0.1670/kWh, I would think that it costs me $1.77 to drive 35.3 miles. However the actual costs are slightly higher because of the power conversion losses when charging. Charging via a standard 110V wall plug in the US is reported to be much less efficient than a NEMA 14-50 hence you’ll be using even more energy to reach the same state of charge.
Tesla’s charging calculator appears to take into account some of these charging loses. According to the calculator, 35 miles of range added to the Model S requires 11.6kWh of energy although I was able to achieve that with through 10.6 kWh as seen through my dash readout. This could imply a 91% charge efficiency but of course this is a very loose calculation and based on many assumptions such as the speed in which you drive, elevation changes and weather. It’s not simple to calculate how much actual energy you’re using to charge your Tesla Model S.
The EKM Digital Submeter
The solution I found was to put a submeter between the EV charge outlet and main power supply. There are many types of meters on the market from basic kWh counters to advanced meters that can broadcast actual use over a wifi network, plot graphs, etc. After doing some extensive research, I decided to go with a metering solution from EKM Metering. My electrician did some independent research and came up with the same brand so I felt pretty good about my choice. I ended up purchasing the 100A kWh EKM digital submeter and enclosure.
My electrician was able to complete the installation in 3 hours with a portion of the time spent on retrofitting the EKM enclosure to accommodate for the larger 240v conduit. Total cost spent for products, labor and materials was $292.
How Does it Work?
The EKM submeter is like an odometer but with an energy readout that continuously increments as power is being drawn. There is no reset button. A blinking red light indicates that 1.25Wh is drawn per single blink of the LED.
Measuring actual energy consumed over a specific time period requires taking some notes. Here are the the measurements and results of my tests:
My results indicate that there’s approximately a 85% charging efficiency for my Tesla Model S which is less than the 91% efficiency that Tesla Motors seems to be using in their online calculator.
I’ll be performing several more tests over a longer period of time. I want to look at power draw differences while the Model S is asleep and also analyze variations in energy consumption due to software updates.
Conclusion
Overall the EKM Digital Submeter is a nice addition to any EV charging setup if you’re looking for a true picture of how much energy usage is going into your Tesla Model S / electrical vehicle. Assuming a $0.167/kWh electricity cost and 325 Wh/mile, the cost of the meter plus installation would require 5,380 miles of EV driving to break even.
If you’re looking for a cheaper alternative, simply add 15% to the energy usage readout on your EV to approximate the true energy cost per EV mile driven. Drive clean and drive smart!
Elon Musk
Trump’s invite for Elon just reshuffled Tesla’s big Signature Delivery Event
Tesla rescheduled its final Model S farewell to May 20 after Musk joined Trump in China.
Tesla has rescheduled its Model S and Model X Signature Edition delivery event to Wednesday, May 20, 2026, after abruptly calling off the original May 12 celebration. The event will take place at Tesla’s factory at 45500 Fremont Boulevard in Fremont, California, the same location where the Model S first rolled off the line in 2012. Invitees received a follow-up email asking them to reconfirm attendance and download a new QR code ticket, with Tesla noting that all travel and accommodation expenses remain the buyer’s responsibility.
The reason behind the original cancellation came into focus the same day it was announced. President Trump invited Elon Musk, Apple’s Tim Cook, BlackRock’s Larry Fink, Boeing’s Kelly Ortberg, and executives from Goldman Sachs, Blackstone, Citigroup, and Meta to join his trip to China this week for a summit with President Xi Jinping. The agenda covers trade, artificial intelligence, export controls, Taiwan, and the Iran war, following weeks of escalating friction between Washington and Beijing over AI technology, sanctions, and rare earth exports. Trump wrote on Truth Social, “I am very much looking forward to my trip to China, an amazing Country, with a Leader, President Xi, respected by all.”
Tesla launches 200mph Model S “Gold” Signature in invite-only purchase
The vehicles at the center of all this are the last Model S and Model X units Tesla will ever build. Priced at $159,420 each, the 250 Model S and 100 Model X Signature Edition units come finished in Garnet Red with a one-year no-resale agreement, giving Tesla right of first refusal if the owner decides to sell. As Teslarati reported, the Model S defined Tesla’s early identity as a serious luxury automaker, and the Fremont factory line that built it is now being converted to manufacture Optimus humanoid robots.
Musk’s inclusion in the China delegation drew attention given his very public relationship with Trump, and the invitation signals the two have moved past and past grievances. Trump originally brought Musk on to lead the Department of Government Efficiency following his inauguration, and despite a sharp public dispute in mid-2025, the two have appeared together repeatedly in recent months. A seat on the China trip, the most diplomatically consequential visit of Trump’s current term, puts Musk back at the table on U.S. economic policy at a moment when Tesla’s China revenue remains one of the company’s most important financial pillars.
Lifestyle
Tesla Semi hauls fresh Cybercab batch as Robotaxi era takes hold
A Tesla Semi was filmed hauling Cybercab units out of Giga Texas for the first time.
A Tesla Semi loaded with Cybercab units was recently filmed leaving Gigafactory Texas, marking what appears to be the first documented delivery run of Tesla’s autonomous two-seater. The footage shows multiple Cybercabs secured on a flatbed trailer being hauled by a production Tesla Semi, a truck rated for a gross combination weight of 82,000 lbs. The location is consistent with Giga Texas in Austin, where Cybercab production has been ramping since February 2026.
The sighting follows a wave of Cybercab activity at the Austin facility. In late April, drone operator Joe Tegtmeyer spotted approximately 60 Cybercabs parked in two organized groups in the factory’s outbound lot, the largest concentration observed to date. Units being staged in an outbound lot is a standard pre-delivery step, and the Semi footage is the logical next frame in that sequence.
En route with @tesla_semi pic.twitter.com/ZfuOjaeLH1
— Tesla Robotaxi (@robotaxi) May 7, 2026
This is not the first time Tesla has used its own Semi to move Tesla products. When the Semi was unveiled in 2017, Musk noted it would be used for Tesla’s own operations, and over the years Semi prototypes were spotted carrying cargo ranging from concrete weights to Tesla vehicles being delivered to consumers. In 2023, a Semi was photographed transporting a Cybertruck on a trailer ahead of that vehicle’s delivery launch.
The Cybercab itself was first revealed publicly at Tesla’s “We, Robot” event on October 10, 2024, at Warner Bros. Studios in Burbank, where 20 pre-production units gave attendees rides around the studio lot. Musk stated at the event that Tesla intends to produce the Cybercab before 2027. The first production unit rolled off the Giga Texas line on February 17, 2026, with Musk posting on X: “Congratulations to the Tesla team on making the first production Cybercab.”
Tesla’s annual production goal is 2 million Cybercabs per year once multiple factories reach full design capacity, with the company targeting a price under $30,000 per unit. Tesla has confirmed plans to expand its robotaxi service to seven cities in the first half of 2026, including Dallas, Houston, Phoenix, Miami, Orlando, Tampa, and Las Vegas, building on the unsupervised service already running in Austin. Musk has said he expects robotaxis to cover between a quarter and half of the United States by end of year.
Tesla has taken home the “Overall Loyalty to Make” award from S&P Global Mobility for the fourth consecutive year, reinforcing Tesla owners’ willingness to come back. The 2025 awards are based on S&P Global Mobility’s analysis of 13.6 million new retail vehicle registrations in the U.S. from October 2024 through September 2025. The complete list of 2025 winners includes General Motors for Overall Loyalty to Manufacturer, Tesla for Overall Loyalty to Make, Chevrolet Equinox for Overall Loyalty to Model, Mini for Most Improved Make Loyalty, Subaru for Overall Loyalty to Dealer, and Tesla again for both Ethnic Market Loyalty to Make and Highest Conquest Percentage.
Tesla’s streak in this category started in 2022, and the brand has now won the Highest Conquest Percentage award for six straight years, meaning it keeps pulling buyers away from other brands at a rate no competitor has matched. Tesla’s retention among Asian households reached 63.6% and among Hispanic households 61.9%, rates that significantly outpace national averages for those groups. That breadth of appeal across demographics adds a layer of significance to a win that some might dismiss as routine.
The timing matters too. After several consecutive quarters of decline, Tesla’s share of U.S. EV sales jumped to 59% in Q4 2025. That rebound, arriving just as competitors were flooding the market with new models and incentives, suggests Tesla’s loyalty numbers are not simply the result of limited alternatives. Buyers are still choosing it when they have plenty of other options.
What keeps Tesla owners coming back has a lot to do with the and convenience of charging. The Supercharger network is the most straightforward example. With over 65,000 Superchargers globally, it remains the largest and most reliable fast-charging network in the world, and owners who have built their routines around it face a real practical cost when considering a switch. Competitors have made progress, but the consistency, speed, and availability of Tesla’s network is still the benchmark the rest of the industry is chasing. Then there is the software side. Tesla has built a model where the car you own today is functionally different from the car you bought two years ago, through over-the-air updates that add continuous game-changing improvements such as Full Self-Driving that has moved from a driver-assist feature to an increasingly capable autonomous system. For many Tesla owners, leaving the brand means starting over with a car that will not get meaningfully better over time, and that is a trade-off fewer and fewer are willing to make.
Tesla is making sweeping improvements to Robotaxi
Starship V3 is here putting SpaceX closer to Mars than it has ever been
