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Tesla Semi truck’s battery pack and overall weight explored
The big question on everyone’s mind–at least on the minds of those who understand the freight transportation industry–is how much the Tesla Semi might weigh. If Tesla’s all-electric semi truck is to be competitive at all, it must be capable of carrying the same loads as current-use semi-trucks in the Class 8 field do.
A big point of contention from nay-sayers and those in the trucking industry who understand logistics was the lack of announcement of the Tesla Semi’s actual weight. Plenty of press was given to the much-touted “80,000-pound capacity” number bandied around by CEO Elon Musk during the truck’s unveiling late last year. That number, however, refers only to the gross vehicle weight (GVW) of the Tesla Semi and is, in fact, exactly the same number used by every Class 8 truck on the road. They’re called Class 8s, in fact, because the 8 refers to that 80,000-pound total vehicle capacity.
What wasn’t given by Tesla was the gross vehicle tare weight (GVTW) of the Semi. This is a far more important number. Where the GVW gives the total capacity of the truck in terms of how much its freight plus the truck itself can weigh, the GVTW gives just the weight of the truck, sans trailer and freight. This number tells logistics experts how much actual freight and trailer the truck can haul legally.
For example, a typical “day cab” configuration 18-wheeler with a diesel engine weighs roughly 32,000 pounds with a relatively lightweight box trailer attached and full fuel tanks. That leaves about 48,000 pounds of freight capacity for the truck. That’s important because, although the truck won’t be loaded to capacity every time, it will be expected to be capable of carrying up to about that weight. Most big rigs on the road are capable of hauling 44,000 or more pounds worth of freight, depending on configuration and trailer type.
Having experience with driving commercial trucks in the past, once hauling a refrigerated trailer that had a freight capacity of 44,500 pounds, I learned that some industries count on freight capacity as part of their logistics costs and will literally fill a truck to its maximum in order to minimize those costs.
In logistics, weight and total freight capacity are highly important metrics in the overall scheme.
What We Know
Thinking about that, then, let’s look at what we know of the Tesla Semi and its potential weight. We know that the truck uses four independent electric motors that are derived from the Model 3, that it has an energy consumption of less than 2 kWh per mile, and that it can be charged to up to 400 miles in about half an hour. We also know that Elon promised 300 to 500 miles of range in total. On that latter point, it’s pretty clear that a “lower range, cheaper option” will be offered as has been done with most of Tesla’s vehicles to-date. So we can assume a 300-mile version and a 500-mile version will be forthcoming for the Semi.
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We also know that the Tesla Semi had eight ports in its charging plug array. We saw this at the unveil in some close-up photos.
It’s clear to us that even if the Tesla Semi isn’t to become a big player in the trucking industry, the idea behind it will change things forever.
What We Don’t Know
What we don’t know is whether Musk and Co have something up their sleeves for the batteries. Much of the speculation regarding the Tesla Semi has been in regards to Tesla Semi’s massive battery pack.
In actuality, having a huge battery breakthrough on a vehicle like the Tesla Semi would not necessarily be a good thing for business. If there is a huge breakthrough, then all bets are off and most of our speculation in this article is moot. That would, however, mean that the sales potential of the Semi would be far lower than it would be otherwise because one thing that logistics companies and fleet managers aren’t interested in are flashy new, breakthrough, and (most importantly) untested, unproven technologies.
To a fleet manager, those phrases mean “breaks often, expensive to fix” and the potential positives will be ignored because of that. No one who wants to keep a job as a fleet manager or logistics purchaser will gamble on something unproven. Like new battery technology for a truck whose primary cost will be in its batteries. Likewise, unless there is a clear benefit in some terms other than pure business (like marketing or potential tax breaks), no board of directors will risk shareholder wrath on new tech either.
Close-up look at Tesla Semi’s drivetrain from underneath
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We can say, as a side note, that most of the orders that have been placed for the Tesla Semi thus far are from corporations and companies who are doing business in areas where the marketing bonanza and potential tax incentives for laying down those relatively low-cost deposits are immense. Most of the companies involved have already invested heavily (and very publicly) in alternative fuel options outside of Tesla over the past few years. We also note the timing of both the Tesla Semi’s announcement (and order-taking) and the before-2018 rush by potential customers to put in deposits.
We reiterate that our not knowing if Tesla has some kind of big battery breakthrough announcement is a big “if” in our analysis here.
What People Smarter Than Us Have Said
Some people who know more than we do about things like math and engineering science have crunched the numbers on the Tesla Semi’s battery potentials. Over at Engineering.com, John Ewbank broke the results down into layman format. Here’s the gist.
If the Tesla Semi uses 2 kWh to travel a mile, then a 500-mile range means 1,000 kWh of power. That is not the actual size of the battery, though, as the charging requirement would preclude a huge pack.
In order to get 400 miles in thirty minutes of charging, Ewbank notes, the charger would have to be 1.6MW to achieve the 800kWh of promised charge in only 30 minutes. Charging at that rate is not possible because the result would be arching in the pack, which would surely be akin to the next Boring Company Flamethrower meme when Semi trucks begin to explode in flames during charging as a regular event. So the charging has to be split up.
Tesla Semi Megacharger port could support 1 MW of power.
The answer is simple, of course, and may explain the strange layout of the eight-port charging hub shown on the Semi at its unveil: there are four battery packs.
Instead of one big pack, four smaller packs (one for each motor, even) are used and are thus charging separately from one another, but simultaneously. Based on Tesla Semi’s Megacharger port configuration, this would likely mean that four of them are positive sides and the other four are grounds. Allowing for a single, huge wire to be plugged into each. The controls for the charging system interface may be plugged in separately (perhaps the oval-shaped black thing to the side?).
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What This Adds Up To
We add up that bit of information plus what we know about the truck and get an estimated weight. Using the current weight of a Tesla Model S battery pack at 540kg per 90 kWh, we can do some simple math to estimate the Semi’s batteries would weigh about 6,000 kg. We aren’t sure about the new battery weights for the upcoming battery updates, but we can assume a 10-15 percent reduction from several factors (storage density, improvements in chemistry, packaging lightening) without being too aggressive or overly optimistic. Going with the fifteen percent reduction, that 6,000 kg drops to 5,100 kg. That’s about 11,244 pounds.
A conventional tractor, as we’ve said, has a tare weight of around 32,000 pounds when fully fueled and with a lightweight box trailer in place. Remove the trailer and the truck itself is about 22,500 pounds. It’s difficult to then go to just the weight of the powertrain components and fuel, but they’re considerably less than 11,000 pounds in all.
Tesla Semi spotted doing a tire-shredding acceleration run down in the wild
Looking at the shipping weight for a crated engine and transmission for a Class 8 truck, we can see that they weigh about 8,000 pounds on average. Add in fuel and other components and another 1,500 pounds (at most) are put on the truck. We then assume that the rest of the truck (framing, braking systems, air compressor, etc) are about the same for the Tesla Semi in order for it to meet Class 8 standards. So we call those a wash.
That means that the Semi, under our estimates, is roughly two tons heavier than would be a standard day cab big truck in the Class 8 category. This means the Semi would be that much less capable in terms of freight hauling that’s offset by its unprecedented all-electric performance. That amount, however, is probably not enough to stop the primary buyers of a day cab truck like this from balking at a purchase. The weight difference alone would be repaid in potential fuel savings, tax incentives, green marketing, and maintenance costs.
The trouble will come with cost differences. If the ROI is not there, most logistics buyers won’t write any purchase orders. But at least we can say that as far as we can tell, the weight differences of the Tesla Semi alone aren’t going to be a huge bar against entry into the trucking industry.
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Lemonade has expanded its innovative Autonomous Car insurance program to Tennessee, giving Tesla owners in the state a substantial discount on Full Self-Driving (FSD) miles. Announced on August 3, the product offers 50 percent off every mile driven with FSD activated, positioning the digital insurer as a leader in pricing insurance around autonomous technology.
The program, marketed as Lemonade Autonomous Car insurance, uses a direct connection via Tesla’s Fleet API (with customer permission) to automatically distinguish FSD-engaged miles from manual driving. Policyholders pay a low base rate when the vehicle is stationary and a few cents per mile when moving, with the 50 percent reduction applied specifically to FSD miles.
If you’re driving a Tesla in Tennessee, FSD miles now cost 50% less to insure with Lemonade. Autonomous Car is now live in TN.https://t.co/4CDTuhyORi pic.twitter.com/QZk4LBIs6f
— Lemonade (@Lemonade_Inc) August 3, 2026
Coverage includes standard protections such as liability, collision, comprehensive, roadside assistance, and Tesla-specific benefits like access to certified repair shops and emergency crash services. Eligible vehicles require Hardware 4, as well as recent firmware.
Lemonade first unveiled the product on January 21 of this year, describing it as a first-of-its-kind offering designed for self-driving cars, starting with Tesla FSD. It began rolling out in Arizona on January 26, followed by Oregon about a month later. Subsequent expansions brought it to Indiana in early June 2026 and Colorado later that month.
Tennessee marks the fifth state.
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Tesla Full Self-Driving gets outrageous insurance offer with insanely cheap rates
The discount rests on Lemonade’s strong belief in the safety of Tesla’s FSD system. The company cites Tesla’s data showing that FSD-driven miles are twice as safe as those driven manually, or associated with roughly a 50 percent crash reduction.
Lemonade Co-founder and President Shai Wininger has emphasized this distinction: “Traditional insurers treat a Tesla like any other car, and AI like any other driver. But a car that sees 360 degrees, never gets drowsy, and reacts in milliseconds can’t be compared to a human.”
He added that “Teslas driven with FSD are involved in far fewer accidents” and committed that as FSD software improves and becomes safer, Lemonade’s prices will drop further.
Tesla Full Self-Driving gets an offer to be insured for ‘almost free’
This approach leverages Lemonade’s existing pay-per-mile technology and AI-driven risk models, which analyze nuanced vehicle data including software version and sensor performance. The company expects the model to reward higher FSD usage with greater savings while supporting mixed households that include both Tesla and non-Tesla vehicles under one policy. Bundling with home, renters, or pet insurance can yield additional discounts.
As autonomous driving technology advances, Lemonade’s state-by-state expansion of usage-based pricing that directly reflects real-world safety data represents a notable shift in how insurers evaluate risk.
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Tesla owners in the five available states – Arizona, Oregon, Indiana, Colorado, and now Tennessee – can obtain quotes quickly through the Lemonade app or website, potentially lowering the overall cost of ownership for vehicles equipped with advanced driver-assistance systems. Further states are expected as regulatory approvals progress.
Tesla has continued to flex the strength, rigidity, and robustness of its all-electric pickup, the Cybertruck. In fact, since 2019, Cybertruck’s ability to avoid dents, dings, and even gunfire has been one of the main selling points Tesla has used to attract buyers who are looking for a vehicle that can handle the most intense challenges.
But that does not mean Tesla is not still actively trying to make it even better.
In a new hardware update, Tesla has decided to change the material of the Cybertruck’s underbody panels from aluminum to carbon fiber, a move that aims to not only increase pricing efficiency but also improve strength.
RELATED:
Cybertruck Lead Engineer Wes Morrill confirmed the change was made to the Cybertruck recently after it was spotted by Coleton Guerin of Out of Spec. This particular trim level was a Cyberbeast, but it is being applied to all trims to keep supply chain efficiency high and have less variance across trim levels.
Morrill said that Tesla tested different materials for the underbody panel protection, and carbon fiber performed better than aluminum, which is what the company was using since its first deliveries in 2023.
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Additionally, there are some efficiency improvements because Tesla can better form the areas around the bolts to keep underbody airflow cleaner than previously.
good eye – it’s a new material. Testing showed it to be more durable than the aluminum while being lower weight and cost. Also slight efficiency improvement since we can better form the areas around the bolts to keep the underbody airflow cleaner than what stamped aluminum allows
— Wes (@wmorrill3) July 30, 2026
Carbon fiber is traditionally lighter and more durable than aluminum, which is why it is such a popular material among luxury automakers, and EV makers will utilize some of the materials around battery packs to save weight.
This is the first instance of Tesla utilizing carbon fiber on the Cybertruck’s exterior to help with overall performance and strength. As previously mentioned, Tesla used aluminum to protect the underside of the body, but it is pretty typical for the company to continue making engineering changes that will improve the car in the future.
Tesla released Full Self-Driving version 14.3.7 yesterday, and after about 90 miles of testing today, it is evident there are some definite fixes from version 14.3.6, which I wrote about last week and called a regression.
Within the first 40 minutes of my drive on v14.3.7, it saved me from getting into an accident with an unaware Dodge Charger driver, and some of the things Tesla seemed to miss in v14.3.6 were definitely improved. All in all, the release so far has some really great performance, and I’m looking forward to testing it further.
For now, here’s everything I noticed with v14.3.7:
Overall Improvement
Just generally speaking from a ride perspective, this was a really great experience. A lot of the hesitancy I experienced on v14.3.6 was gone. There were no instances of brake-stabbing, wheel-jerking, or any uncertain or unconfident movements. It was void of anything that I felt made it timid with v14.3.6.
The one thing I do hope to see down the road is a smaller need to adjust Speed Profiles so often. Because Tesla calls FSD “Supervised,” I’m okay with needing to hit the scroll wheel a few times a drive.
However, I hope that things can be incrementally improved upon with speed. Sometimes it’s too fast; other times it’s too slow. It’s a difficult thing to hone in and refine, but I hope it eventually gets there.
I didn’t notice any significant left lane camping or any behaviors that were completely out of line. I am hopeful that this opinion does not change, but after driving a few days with this version and putting it in a variety of different situations, you are exposed to more behaviors, some of which are not necessarily what I’d prefer.
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The big things to notice, at least in my experience thus far, are that the major issues with previous versions — meaning the braking stabbing and wheel jerking — simply weren’t there. That’s enough to already consider this progress compared to .6.
Manual Signal Override is More Responsive
On .6, I had quite a few issues with FSD ignoring my manually input turn signals. If Tesla wants to call it “Supervised,” then the car should not ignore any input the driver gives. If I touch the accelerator on FSD, the car speeds up.
🚨 Tesla FSD v14.3.7 obeying manual turn signals https://t.co/6eqToXpQfC pic.twitter.com/vHBlFQ4PDV
— TESLARATI (@Teslarati) August 2, 2026
The car did a great job of obeying my turn signals when I wanted it to change lanes, which is welcome.
Parking Lot Performance
Before .6, I traditionally took over in nearly every parking lot my car entered, because I knew it would not park somewhere that I wanted, and usually, it was just a tad too timid in this setting.
The one bright spot of .6 was how well it handled parking lots. This continued with v14.3.7:
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I’m always really happy to see progress at all, but once parking preferences come to FSD, as long as this performance is still around, that could potentially be the biggest improvement I’ve seen in FSD in the year I’ve been using it personally on a daily basis.
Full Self-Driving Averts Disaster
A Dodge Charger changed into my lane without checking if I was there, running me off the road. FSD made the initial avoidance maneuver; I grabbed the wheel out of instinct, looked in my side mirror to ensure I had nobody following closely behind, hit the brake, and straightened the car back up to avoid a curb:
🚨 Guys this is why you all NEED to stay vigilant behind the wheel, even on Tesla Full Self-Driving
Human drivers are UNHINGED and have no idea what they’re doing anymore. This was a kid obviously younger than 20 years old with zero awareness.
First drive with v14.3.7 https://t.co/1vTbCMpCn8 pic.twitter.com/lz7KKEF6bj
— TESLARATI (@Teslarati) August 2, 2026
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There have been quite a few responses to this video stating that I should never have grabbed the wheel. To be honest, I really wish I had not done so, because I do believe FSD would have avoided any sort of collision with anything, including the car or the curb.
However, this was the first time I had ever been this close to being hit while using FSD. My natural reaction was to take over. I think if I had had something like this happen before, my reaction might have been different.
Hitting the brake avoided hitting the curb, while FSD swerved to avoid the car. My concern after the car was clear of my front end was the curb. All in all, I’m really happy with how things turned out, and I think anyone could be a critic of how I handled it. I only had a split second to really make a decision, and thankfully, any damage was avoided.
It is clear FSD managed to avoid the car coming down before I was able to. I truly credit FSD for avoiding the collision.
What Needs to Improve
Better Recognition of Potholes, Uneven Roads, Sharp Changes in Roadway/Bumps
On Friday, my Fianceè and I were in the car, and FSD was driving us. We crossed over a roadway that has a traffic light, and FSD was traveling at 40 MPH on Standard, 5 MPH over the speed limit. Everything was more than reasonable.
However, the road we were crossing at the light has a major bump both as you start and finish crossing it. Without a speed reduction, your car can go airborne. The Tesla did just this on Friday on v14.3.6; it was an uncomfortable bounce that pretty much confirmed I would not ever let FSD go over again unless we were sitting at that intersection when there is a red light.
I even tried scrolling down into Sloth quickly, but I ended up just taking over:
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This is that big bounce that I mentioned in the quoted post.
It’s just a tad too drastic to take at the speed FSD wants to go over it. You can see me quickly swipe down into Sloth, but I intervened. https://t.co/K20PK9ysBg pic.twitter.com/81Oc82ZJcZ
— TESLARATI (@Teslarati) August 2, 2026
A few people have said it remains related to the vision-based approach and its difficulty comprehending 3D. This is a huge issue because this can cause serious damage at certain speeds.
Navigation
Nothing new here. I still turn off “Online Routing” quite frequently to get the car to take logical routes from time to time.
Auto Wipers
Auto Wipers are just plain bad. I really hope Tesla just uses a rain sensor. I thought they had improved at one point, but I still get dry wipes, Speed 4 on a drizzle, and Speed 2 on a steady rain. In reality, these should be switched.
You can watch our full review of Tesla Full Self-Driving v14.3.7 below:
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🚨 Tesla Full Self-Driving v14.3.7 saved me from an accident! FULL REVIEW: https://t.co/1vTbCMpCn8 pic.twitter.com/9mHmKVoMVA
— TESLARATI (@Teslarati) August 2, 2026
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