– Ben Martens

Electric Vehicles

Tesla Road Trip

Welcome to another Tesla Tuesday!

Yesterday I wrote about our trip to Lincoln Rock State Park. Usually when we go camping, we take the truck, but since we were staying in a cabin and it was such a short trip, I decided to give the Tesla a shot instead.

With the Cascade mountains in between us and the park, it would have been pretty tight to make it all the way there and back without charging. I didn’t know what charging options would be available at the campsite, so on the way out, we paused at the Leavenworth supercharger for a quick hit. That charger is so convenient because it’s in the same parking lot as Dan’s Market which is quickly becoming our favorite grocery store in Leavenworth. We had planned to buy some of our food there anyway instead of lugging a cooler across the state. I actually had to let Tyla finish the shopping because our charging was done before our shopping was.

I had intentionally not topped off the car there in case we could find a way to get free charging at the park. The only easy option was a 110v outlet on the back of our cabin. It was a little too far for our Tesla mobile charger to reach, but I had bought along a beefy 12/3 extension cord. Charging on a standard home outlet is exceedingly slow, but we had time and it was free so why not.

On Saturday, I drove over to an unused RV spot and plugged into their 240v 50amp circuit which charged about 7 times faster than the outlet at our cabin. After a couple hours a ranger stopped by and asked me to move the car though just in case someone happened to have that site reserved. I get that it was the rule and I didn’t put up a fight, but it seemed unlikely that in a park with 100+ empty sites, that specific one would be reserved. In retrospect, I wish I had put a note in the window with a short explanation and my phone number so that I’d at least save them the work of looking up my license plate if they didn’t like it.

I didn’t leave the mobile charger plugged in overnight because I wasn’t sure how waterproof the whole setup was, but by the time we left, we had added about 25% to the battery which meant we could easily make it home without a stop, and it also saved us about $7 versus charging at the supercharger.

Yes, you read that right: $8. I love the challenge of being as frugal as I can with my charging to really milk the most savings we can, but when you look at the work required to save even a few bucks, it really doesn’t pay off unless you’re having fun doing it.

While it was a little tricky to fit Elijah’s bike into the car, all our stuff fit pretty easily. The frunk and the under trunk storage swallow up so much gear. And I was glad we had all wheel drive for the trip through the pass. There was quite a bit of snow over the weekend but thankfully we missed the worst of it. I did have chains along just in case.

All in all I’m glad we took the Tesla instead of the truck. These adventures with the Tesla are helpful in expanding my comfort zone. We’re still hoping to do a long road trip with it this summer!

One Year of Gas Prices

As part of my effort to closely track the cost savings of our Tesla, I wrote a program that uses Gas Buddy to track the prices of the six gas stations closest to our house with the logic being that these are the places we’d be most likely to buy gas from. In reality, we buy almost all our gas at Safeway but for some reason that one doesn’t usually have prices listed on Gas Buddy.

That program started running a year ago and below is the chart of how things have changed. The orange line (the cheapest gas) is usually the Costco near us.

When I was doing the calculations about whether I could save money with a Model Y versus buying another Ford Escape, I had planned on $3.50/gallon. So with the average gas price barely ever dipping below $4/gallon, I’m ahead of my estimated savings mark. But I’ll more on those specific savings numbers when we reach 20,000 miles in a few months.

Cold Weather Tesla Experience

Welcome to another Tesla Tuesday!

Our Model Y is parked in a garage and the temps outside rarely get much below freezing. Those two factors means that when I read the user manual, I skipped over all the cold weather information. That came back to bite me a bit when we spent a weekend in Leavenworth.

On our second night there, it got below 20 degrees and snowed an inch or two. We were leaving that morning so when I woke up around 6am (like I always do), I snuck out to go charge so we’d be ready to go when everyone else was awake. I turned on the climate control before going out to the car, brushed it off, and I was able to open the car door just fine. If that didn’t work, I knew I could use the app to release the door as well.

During the 4-minute drive to the supercharger, I told the car where I was going so that it would start preconditioning the battery. But when I arrived and tried to open the charge port, it wouldn’t open. Uh oh. I sat in the car for a while reading through the owner’s manual and found out that there is a small heater inside the charge port that is engaged with the rear window defroster. I turned that on and when I checked the charge port 5 minutes later, it opened easily.

So that was annoying but it’s not a big deal now that I know about it. I think the big takeaway was experiencing firsthand how the car would behave in cold weather. A few days ago, Tesla released a video talking about the innovation in their heat pumps, and my experience shows that it’s working. When we drove there last summer in 100 degree weather, we averaged right around 300 Wh/mi. On this trip in the cold, we averaged about 310 Wh/mi. In 60-70 degree weather with little HVAC usage, I’d expect around 265-270 Wh/mi. So temps in the teens or above 100 mean maybe a 10-15% increase in battery usage.

Where I did see a lot of loss was in warming up the car after it had been sitting. I didn’t know how long it would take to warm up and defrost so I probably let it run longer than it should, but between the normal loss from the car sitting around and the additional loss from having to do more work to warm up, I could see a 2-3% drop before I drove it the next morning. Thankfully it only costs $0.24 to fill 3% of the battery, but if I had planned a trip that was cutting it close on battery, I would want to factor that in.

We’re planning a multiday, 1000+ mile road trip next summer and I really want to do it in the Tesla so this was another good learning experience. That trip won’t be cold, but it’s all good data and it also helps me feel comfortable getting more of the usable range out of the car. When we do that trip, I want to do a full blog and possibly an accompanying video showing what it’s like to road trip in an EV. Maybe someone will find it interesting now, but I think it will be very interesting to watch it in 20-30 years when there are EV chargers everywhere and battery technology has progressed even more.

Random bonus story: As we were driving around Leavenworth looking for parking, a blue Model 3 was doing the same thing. I happened to notice their license plate and it was sequentially less than 50 numbers away from ours.

Why Tesla?

Welcome to another Tesla Tuesday!

If you’re interested in an electric vehicle, you might be wondering why Teslas are so popular despite their higher price. The price has gone up quite a bit from when we ordered ours, but we were asking the same question back then too. My one-word response is: experience. Other companies are making lots of announcements about EV models, but it’s not as easy as writing an idea on paper. The supply chain, manufacturing process, and support models are all quite different for EVs. Tesla has a ~10-year head start on other companies.

For example, battery efficiency is a mix of not just the physical design of the car but also the software that manages the battery. Take a look at this report which shows the energy used per mile. Our Model Y Long Range with 19″ wheels is one of the most efficient vehicles you can buy despite the largish size. Even the Model S Plaid (one of the fastest vehicles on the planet) has better efficiency than a Nissan LEAF.

As I was thinking about this post, a good video was posted to YouTube about this exact topic.

I don’t really understand the title image and the title itself is click-baity, but the video gives 10 good reasons why you might want to choose a Tesla over another EV.

  1. Direct sales – no surprise markups, no dealer haggling
  2. Safety – Model Y is both the safest car and the best at preventing accidents as tested by multiple agencies
  3. Charging – Road tripping in anything besides a Tesla is painful
  4. Depreciation – EVs hold value better than ICE because they run much longer and Tesla’s hold value much better than any other car
  5. Built in the USA. Teslas are the most American made vehicles.
  6. Technology – Over the air software updates every month
  7. Dash Cam and Sentry Mode – Alerts to your phone and recorded footage from all exterior cameras
  8. Autopilot – Keep centered in the lane on almost any road, enormous investment in AI so it gets better with every update
  9. Experience – There’s a lot to learn when a company starts doing EVs and Tesla is very far ahead of anyone else.
  10. Tesla App – Precondition, scheduling, valet mode, charging stats, avoiding peak rates, sentry mode live stream, scheduling service

I tried to pick my top 3 from that list but it’s too hard. We loved the direct sales model. It’s awesome to know that my family is driving around in the safest car on the planet. Charging doesn’t worry us on road trips. Our car gets better every month with new software updates. Autopilot is fantastic and makes driving so much more enjoyable. And as I already said, it’s comforting to buy with the company that is effectively operating 5-10 years ahead of other companies. Ford and Volkswagen are doing better than most, but then you have behemoths like GM that are struggling mightily.

That being said, I’m happy whenever someone buys a non-Tesla EV. Competition is healthy for the market and there’s so much demand for EVs that even Tesla can’t provide enough vehicles to satisfy it.

Choosing An EV With Enough Range

Welcome to another Tesla Tuesday!

Range is a key factor when picking an EV. Until superchargers are as ubiquitous as today’s gas stations, EVs do require extra planning. So how much range do you need?

For normal daily use, the only factor to consider is whether you will comfortably make it home at the end of the day so it can charge overnight. I underestimated how much I would love knowing that my “tank” was full every single morning! On a road trip the range can impact how many stops you make along the way.

Just like in a gas car, your driving style can dramatically impact your range. We average around 250 Wh/mi (watt hours per miles) which means our 75KWh battery is good for 300miles. The EPA estimated range is 330 miles, but that number always seems to be high for all cars.

As the car gets older, the batteries are going to lose some effectiveness. There are lots of studies about this, but data suggests that we’ll lose 5% of our range after 50,000 miles and then another 5% by the time we hit 150,000-200,000 miles. At 50,000 miles, our range will be an estimated 285 miles of real-world driving.

Most current battery technologies do not like to be charged up to 100% or drained to 0% (though Tesla has some models that do like to be charged to 100%.) The Tesla manual suggests charging to 90% and not draining below 10% for regular use. This knocks our 285-mile range down to 228 miles.

It’s not just driving that will impact your range. The car is using battery all the time. Teslas all can record from four cameras around the car while they are parked, and your battery management system might be running various fans to heat or cool the battery. If your day involves a lot of sitting in parking lots, plan for another one mile of loss per hour. There’s also a feature called “Cabin Overheat Protection” which makes sure the temperature in your car never gets above 105. If you have that enabled on a sunny day, you’ll be losing battery to run the air conditioner. Let’s assume we’re parked in the hot sun at work all day and knock off another 15 miles. That brings our example down to 213miles.

Heating and cooling the passenger compartment can use a significant amount of energy too so you’ll want to build in some buffer for that as well.

We put about 75-85 miles per day on the car so ~200 miles of range is plenty. It gets charged up every night and we’re ready to go the next day. The only time I really think about range is when we’re taking a longer trip.

So why am I sharing all this? It may sound like I’m hating on EVs, but my goal is to encourage you to get the biggest battery you can get if you’re thinking about an EV. Even if you’re only planning to use it for your normal daily routine, take your normal daily mileage and double it. Use that number when you’re considering various vehicles. Assume you’re only going to comfortably get ~1/2 to 2/3 of the EPA rated range.

We don’t think about this as much with gas cars because it’s easier to stop and fill them randomly. But on the flip side, if current battery ranges are more than enough for almost everyone’s daily commute, would the market really going to pay for even bigger batteries? What’s the incentive for car companies to shove bigger batteries in the car when that’s already a huge part of the cost of the car? A better fix is getting people to realize that they have more than enough battery for daily use and getting the fast-charging network built out more for long trips. This whole post will probably feel silly in 20 years.

Optimal Efficiency In A Tesla

Welcome to another Tesla Tuesday!

When driving a car powered by a standard internal combustion engine, the speed that gives you the best fuel efficiency is somewhere shortly after the point where you can cruise in the highest gear. That’s generally around 40-45 miles. But electric vehicles don’t have gears, so what speed can I drive if I really want to get the most range?

The short answer is that somewhere around 25-30mph gives optimal range, but the full answer is more complicated.

Other than driving speed, one of the biggest factors is how much air conditioning or heating is being used. Heat in a traditional car is free except for the blower motor, but in an electric vehicle, you pay to generate both hot and cool air. It’s a battery load that varies with temperature, not speed. Other electric loads such as headlights and wipers along with things like tire inflation, elevation, wind, and extra weight can all play a part as well. Most tests are assuming that HVAC is not used and that all the other factors remain constant. Real world values will vary.

Tesla did a blog post back in 2008 about this topic with the original Roadster. Unfortunately the images don’t load for that post anymore. They have an updated post from 2012 when the Model S was coming out and that does have all the charts available.

Another chart that I found with an image search shows a similar curve for the newer Model 3.

A post on does a breakdown of how the Model S range varies with the outdoor temperature. They pulled a lot of real world data donated by owners to generate this chart. It shows how much range can be lost when it’s cold, mostly because of cabin heating. The falloff in cold weather performance is one clear area where EVs lag behind traditional vehicles, but if you go look at Norway (a place we’d all agree is generally “cold”), more than 80% of their new cars sold are EVs. The whole country is transitioning to it. So while this is something to keep in mind, it’s far from a blocker for adoption.

The curves in these charts are generally more interesting than the actual y-axis values because those values will depend on your specific model. And while the shape of these curves is pretty consistent across the Tesla lineup (except maybe the Model X which is huge), they’re no the same across brands. You’ll generally find that there aren’t many cars that sip their battery power more efficiently than Tesla. Their experience really pays off in that category.

A lot of this data is available because Tesla is collecting so much of it and it can be easily shared/collected for these studies. These same laws of physics apply to traditional cars too, but we’re a lot less conscious of it because we can’t see the data as easily. I’ve never heard anyone ask “How much range did you lose when you changed your rims?” or “How much range do you lose because you added running boards to your truck?” But with a Tesla, it’s relatively easy to measure all these impacts.

So now I have a car that’s fun to drive, cheap to operate, and spewing out huge amounts of data! Win win win!

United States Fully Electric Vehicle Sales

Welcome to another Tesla Tuesday!

In the last three months, one in every 26 cars sold in the United States was a Tesla.

Staggering! In the third quarter of 2022, 6.1% of all US auto sales were full electric vehicles with about two thirds of those being Teslas and most of the Teslas are either the Model Y or the Model 3. With the way things are going now, it is looking like the fourth quarter will end with Tesla will be one of the top 10 auto brands by quarterly sales in the United States. They’re growing very rapidly while traditional auto maker sales are still roughly flat.

Electric vehicles are very common in my area. I pulled up to a stoplight the other day driving our Model Y and of the six cars waiting at the light with me (all going the same way, not spread around the intersection), FIVE of them were Teslas. Ford is coming on strong too and looks to be in solid possession of second place. I know that I’m living in a bubble of EVs so while the percentage of EVs being sold is huge out here, I didn’t expect it to average out to 6.1% for the whole country.

There’s a long way to go as the country shifts to EVs, but it’s awesome seeing so many people choosing this on their own and not being forced into it by legislation. EVs might not be for everyone yet, but they’ve certainly earned serious consideration in every car purchasing decision.

First EV Savings Milestone

Welcome to another Tesla Tuesday!

I’ve mentioned before that I’m pulling in a lot of car stats with TeslaMate. I’m also using the GasBuddy API to record the prices at the six gas stations closest to my house. This lets me calculate how much I would be spending on gas if I drove the exact same distances at the same time. I assume that I would fill up every day which isn’t accurate, but over time, it should be nearly spot on.

I take all that gas price data and compare it against the cost for every charge I’ve put into the car. Most of the charging is done at home (92%), but if I’m on the road, I have all those prices as well too.

So if I compare my actual charging costs versus the estimate gas prices for the same driving pattern, we have saved our first $1000! Despite the high entry price, we bought this car because I believe it will be cheaper than if we bought another Escape. Using my conservative estimates and the lower gas prices from last summer, I expected to save $1000 every ~8000 miles, but we hit the first $1000 of savings at 5800 miles.

Digging into those charging costs at home a bit more, here’s a chart for our electric usage for the last 11 years:

You can see where we got the new car at the end of the chart, and our monthly usage can vary quite a bit based on how much we drive. Do you see that spike back in January 2014? That winter we tried running a space heater in one room. I cut that off quickly after monitoring how much power it used. The space heater wasn’t cheaper than just turning up the furnace a bit more. So if you’re nervous about the additional cost of charging an EV at home, look around your house at those space heaters. If you have one or two of them running, that’s roughly the same as charging an EV (caveat caveat caveat but they can be in the same ballpark.)

Gas savings alone won’t make this car cheaper. I’m also counting on lower total service bills (no oil changes, less moving parts to fail, etc) and a higher resale value. We won’t know how all that plays out for many years, but it’s fun to see it working out better than planned so far!

Mountainous Tesla Trips

Welcome to another Tesla Tuesday!

We took the Tesla on our trip to the Sunrise Visitor Center at Mt. Rainier (200 miles round trip). Before the trip, I had used to check how the charging would work out. I’ve done a bit of work on that site to tweak the settings to pretty accurately match our real-world behavior and it said that if I left home with 90% charge, we’d hit the visitor center with 45% and we’d get back home with a comfortable 24%. I didn’t think much more about it

When we got in our car to leave, I punched the route into the car and it said that I would get to Sunrise with only 28% charge but then we’d get home with 10%. I knew that we had to gain a lot of elevation going up to 6400 feet at the visitor center, but those numbers seemed wild and since I’ve had experience with those estimates being pretty far off in the mountains, I was a bit nervous. But we went for it anyway.

My battery concerns were further fanned by ~30mph headwinds once we reached Enumclaw. That sucks energy too, but how much? The car was still confident that we’d make it back home fine, and I knew there were enough superchargers along the way to use as a fallback if needed. In the end,

Sure enough, the climb up to the visitor center did take a lot of battery, but not nearly as much as the car had originally estimated. We arrived with 44% battery remaining, only 1% off from what had estimated! I guess if the Tesla estimate had to be off, I would prefer for it to be pessimistic like this, but that’s so far off that it feels unhelpful. (Note that the trip shown in the image is only the distance from Enumclaw to Sunrise because we had a bathroom stop.)

The green line is actual usage and the gray line is estimated usage.

I’ll have a separate post about the hike, but after the hike, we headed back down the mountain. In a normal car, the best you can hope for is that your car smartly uses engine braking to generate enough power to run the AC, radio, lights, etc and you use no gas when you go down the mountain. In an EV, the story is even better. Not only is it running all of those things for free, but it’s also storing up all the extra energy that it doesn’t need right away. On the 16 miles down from Sunrise back to Hwy 410, we charged back up to 47%. We then proceeded to use that extra energy to drive an additional ~30 miles before we were back at 43% charge. So yes, we used more battery going up the mountain, but then we drove for 50 miles from the top for free!

This shows how much energy was consumed driving up and then coming down.

At the end of the day, we averaged 227 Wh/mi for the trip. We average 250-265 on a normal long trip so I don’t know if the lower usage on this was due to something with the mountain, changing winds, or the fact that most of the roads on this route were 50mph speed limits instead of 60-70 on the highway.

I’m continuing to learn more about what to expect from the car, and each time we do a trip like this, it makes me more and more comfortable exploring the limits of our range.

First Tesla Road Trip

Welcome to another Tesla Tuesday!

We recently took our first overnight road trip with our Model Y. We’ve gotten very used to daily driving/charging routines and never worry about running out of battery, but what would happen on a longer trip where we had at least one mandatory charging stop and a few nights away from home?

Our destination was about three hundred miles away, and while the Model Y has an estimated 330 miles of range, just like gas cars, you’re unlikely to hit that in real life. Plus, that would mean charging to 100% (not great for the battery) and discharging to almost 0% (not great for the battery and then how would we get back home?) So there would be at least one stop for charging along the way.

Another factor to consider was that our destination was far off the beaten path. The closest slow Level 2 charger (fairly slow, similar to what we have at home) was about 30 minutes away and the closest supercharger was more like 45 minutes away. Couple that with some mountain driving and I estimated that we needed to leave the last supercharger with about 50% battery to make sure we could get there and back.

The online Tesla road trip planner isn’t that useful if you’re not going to have destination charging because it doesn’t let you specify how much charge you want to have left when you arrive or get insight into all your options for planning the route. I prefer to use On that site, I could tell it my real-world watts per hour average (265), how much charge I’d leave home with (90%) and how much I wanted to arrive with (40%). Then there are even more options for whether you’d like fewer (but longer) stops or more (but faster) stops. The Tesla batteries charge the fastest from about 15-40% so if you’re really optimizing for ~5 minute charging stops, it’s best to stay in that range, but obviously that means more stops along the way, so you have to balance it all out.

My family needs to stop for a lot of bathroom breaks. I plan one every 60-90 minutes and sometimes we’ll get lucky and stretch it out to 2 hours. On this trip, I planned one required charging stop that was right next to a Panera around lunch time. Then I had a couple optional stops before and after that where we could get some electrons while using the bathroom.

On the way down, we ended up doing that lunch stop and then one more stop at the last supercharger before heading off into the mountains. The charging worked out fine, my estimates were good, and we arrived with more battery than planned because our bathroom/food stops were slower than the chargers. In fact, when we stopped for lunch, I had to go out and move the car because it was done charging before our food was done being made!

There ended up being a 110v plug that was right next to where we parked, and while that’s a slow way to charge, we were there for a few days so it didn’t matter. I plugged the car in on the day before we left, and we rolled out with 85% charge. On the way back, we made just a single stop for charging and food. Since I charged up pretty far and it gets slower as you go, that one took longer (29 minutes to go from 28% to 84%) But by the time we got our food and used the bathroom, we only waited about an extra 10 minutes and it saved us from making any more stops. We needed a bit of extra juice on that charge because after we got home, we had to head straight to school for a meeting and a trip to/from school is about 14% of the battery.

When planning the road trip, I had been thinking about how much money we would save versus driving the truck. I get about 20.5mpg on a road trip in the truck and with gas averaging around $4.80 that would have been $140 in gas. I estimated that the same trip in the Tesla would be about $15 in electricity. That was a mistake because I forgot that superchargers are more expensive than charging at home. So overall, it was more like $40 in electricity. That’s still a big savings and the savings are even greater if you factor in maintenance costs.

The truck has so much room that it’s super easy to pack and easy to move around to get comfortable. We were nervous about having enough room in the car since we’re used to packing in the truck, but when we hit the road, we had tons of extra space. The frunk and the under-trunk storage suck up so much stuff! Even with a big cooler in the trunk, we were at about two-thirds capacity.

Having autopilot on the long drive was nice. I could go for long stretches of road without constantly monitoring my speed or making minor corrections to stay in my lane. Traffic was heavy the whole way so it was annoying to come off the autopilot (lane-keeping) feature every time I wanted to change lanes, but in the back of my mind, I knew I could have paid money to avoid that so it wasn’t too bad.

I spent a lot more time planning our route than I would have with the truck, but now that we’ve got the first big road trip under our belts, I think future ones will be easier. It’s nice to know that the car is also watching our battery and if we ever did something dumb, it would scream at us and direct us to a charger. I think long road trips in the truck will be more annoying now without the benefit of Autopilot. It’s amazing how much less fatigued I felt after a long drive just from not having to spend the energy to stay in my lane. It doesn’t seem like much but it really adds up over the hours. And since the battery lasts a lot longer than our bladders, the charging stops weren’t much of a factor other than having to plan to stop at certain places.

I call this experiment a win and look forward to more road trips with our Model Y!