How Long Can A Tesla Keep You Warm In A Frozen Traffic Jam? “Dirty Tesla” Finds Out [UPDATE]

In an opinion piece in the Washington Post (which Steve Hanley already skewered), the author wrote about the recent icy traffic disaster on I-95 in Virginia but imagined a scenario where the only vehicles were EVs. The issue, the writer claimed, was that if everyone had been driving EVs, the mess could have been worse.

He brought up the fact that batteries lose capacity more rapidly in cold weather, but noted that automakers can and do mitigate cold weather range anxiety. The author pointed out that Tesla’s heat pump helps extend the winter range, but neglected to balance the opinion piece with information about how fossil-fueled vehicles have similar problems.

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According to FuelEconomoy.gov, a normal gas car mileage is around 15% lower at 20°F during city driving than it would be at 77°F. It can also drop by as much as 24% for short three- to four-mile trips. It’s even harder on hybrids and EVs. Yes, EVs drop 39% in mixed city and highway driving, but in most cases with EVs, you don’t need to burn much fuel at all while idled — unless you own a hybrid, but even then, you might not. So, if we are going to be fair and balanced, we need to point out that, yes, EVs in general do have a higher drop when driving, but this is offset with the fact that EVs use minimal energy when not driving. That said, they do use energy to heat the cabin and much concern is about how much they use. Let’s turn to someone in a position to examine this better.

UPDATE: Also see this tweet reportedly providing perspective on how a Tesla handled the traffic jam:

Simulating The Scenario

YouTuber “Dirty Tesla” wanted to answer the question “how long can a Tesla keep you warm in a frozen traffic jam?#8221; The video is separated into six parts: the Virginia traffic jam disaster, setting up the experiment, a two-hour check-in, going over the Washington Post article, a 12-hour check-in and extending the test to 18 hours, and then the final results at both 12 hours and 18 hours.

Dirty Tesla rightly noted that the accident opened up a dialogue about how EVs would fare in a similar situation. It should be noted that there were a few Tesla owners caught in the traffic jam and in one of the comments to his video, a user noted that a pregnant woman from the Facebook Tesla Divas group shared that she was stuck in her Tesla for 16 hours during the traffic jam. Her battery was at 74% and only dropped to 61% by the time she got home. She simply turned on Camp Mode and slept.

Other commenters shared how their Teslas fared during the Texas winter storm last year, and a Nissan LEAF owner shared that they were stuck in traffic for 6 hours once and used the seat heater and their electric blanket. They only used 15% percent of the battery and their LEAF was a 2012 model. You can view more of the comments to his video here.

The Experiment

Dirty Tesla noted that his experiment included two Tesla vehicles. One is a 2021 Model Y with the new heat pump and the other one is a 2020 Model X with the old resistive heater. The resistive heater in the Model X uses more energy to keep the temperature comfortable than a heat pump does. However, the Model X has a larger battery. The Model X had 90% charge and the Model Y had 91% charge. Neither car had been pre-warmed or heated and the battery packs were cold. Also, he wasn’t in the vehicle and this makes a difference because the human body naturally generates heat. It may not feel like it during cold weather, but it does make an impact on experiments such as this one.

He wanted to see how bad this could get. He pointed out that the temperatures in Virginia during the traffic jam were in the low 20s; however, in Michigan when he started the experiment, it was 15 degrees and had dropped to 12 degrees around the 2-hour check-in. He also set the temperature in both vehicles to 70 degrees.

12 Hour & 18 Hour Check-in

To answer the Washington Post’s question, the Teslas did pretty well during 18 hours of freezing temperatures. He noted that he used solar at home to charge his cars but included the cost of electricity for those who may not have solar at home.

12 Hour Check-in

The Model Y battery level went from 91% down to 58%. It used 26.5 kWh at 0.16 per kWh, which would cost $4.22.

The Model X battery dropped from 90% to 47% and used 43 kWh at 0.16 per kWh, which would cost $6.88.

18 Hour Check-in

During this portion, he had lowered the inside temperatures of the cars to 60 degrees.

The Model Y battery went from 58% down to 48%, with 8 kWh used at 0.16 per kWh costing $1.28.

Conclusion

Although he didn’t include the results for the Model X at 18 hours, it should be noted that it cost under $10 to stay warm in freezing conditions. However, as he emphasized, with planning for emergencies such as the Virginia icy traffic jam disaster, one could survive up to 36 hours in their car. He also noted that both ICEVs and EVs have their advantages and disadvantages during emergencies, but I want to emphasize that the average American who owns a gas car and thinks EVs are ill equipped to handle emergencies probably spent more than $10 to keep warm during this event — much more.

Typical misinformation, or FUD  (fear, uncertainty, and doubt), often permeates the collective during disasters such as the one in Virginia. And the Washington Post — which is a news organization with access to research, information, and data — chose not to use that and spread the idea that it would have been worse off with EVs than without. Now, if the EVs weren’t Teslas, how would they have fared? I’d like to see similar experiments with the Ford Mustang Mach-E, Nissan LEAF, and other EVs. However, I don’t own any of those (or a car at all for that matter) and I live in south Louisiana where at the moment it’s in the 70s outside.

Sadly, we live in a world where FUD is profitable and the truth isn’t as appealing. Thankfully, there are good people debunking the FUD and proving the misinformation for what it is.