Following the Virginia shutdown of Interstate 95 that left countless people stranded in freezing weather overnight earlier this month, there was a surprising amount of news coverage making offhand comments about how victims would have been better off if they all were driving electric vehicles (Ed. note — there was also this Washington Post op-ed in which the author worried that an EV would be a poor vehicle to be stranded in And this Vice rebuttal to that article). While it seemed an inopportune time to advertise for EVs, it’s an interesting premise and encouraged Car and Driver to conduct a head-to-head experiment between a Tesla Model 3 and Hyundai Sonata N-Line to see who could keep the cabin warm for the longest period of time when stranded.
Realistically, you’d be better off in whatever vehicle is yielding the heaviest fuel tank or least-depleted battery when traffic stops. But there are other factors to consider. Idling an internal-combustion car for extended periods of time is not recommended and doing so when totally snowed in could potentially trap harmful exhaust gasses if the exhaust is not kept clear. Meanwhile, EVs are notorious for having their battery chemistry altered by colder temperatures. This is especially true if they lack the relevant thermal management systems, resulting in the maximum range being diminished by as much as 30 percent.
Earlier testing of Tesla vehicles has shown they tend to perform much better in colder environments than other EVs, however, making the Model 3 an ideal candidate for the matchup. The same might not be said of the Hyundai Sonata, though its 14.8-gallon fuel capacity and 2.5-liter motor make it a decent representative of the average commuter car. Keeping in mind that the experiment fell short of the kind of rigor necessary to be truly scientific, Car and Driver placed them both outside on a 26-degree day that dropped to single digits by nightfall.
The Model 3 was placed in camp mode, allowing the vehicle’s climate control system to remain active while the vehicle is parked. But the Sonata, which automatically shuts itself off after a prolonged stint of running without any inputs, had to have that particular function disabled. However, the outlet was unable to shut off the vehicle’s automatic headlamps (a standard annoyance on modern vehicles) and opted to tape over them to reduce the likelihood of making it a beacon for would-be thieves.
It should be said that the mere fact that you cannot customize which systems you want to remain operational on the Hyundai means the test started with a noteworthy handicap already in play. But the Tesla was using an older model resistive heater that’s supposedly less energy-efficient and had 40,000 miles on the odometer with testers estimating its 80.5-kWh lithium-ion battery pack had lost around 8 percent of its maximum charge over the years. Testers also said they failed to pre-condition the battery beforehand.
From Car and Driver:
The Model 3 started with a 98 percent state of charge, and we didn’t precondition the battery. In a real-world traffic jam situation, however, the battery and cabin would both be warm, not to mention it likely wouldn’t be near a full charge. But, despite cooling down the cabin to 47 degrees prior to the test by opening the windows, we didn’t see a significant decrease in battery percentage as the cabin rose to 65 degrees. We finally plugged it in nearly 37 hours later—with 17 percent battery remaining and an indicated range of 50 miles. The battery pack depleted at an average rate of 2.2 percent per hour; put in other terms, it could theoretically last a maximum of 45.1 hours, or just under two days.
We stopped the Sonata just after 24 hours, after it had consumed slightly less than a half-tank of fuel. Its average consumption idling worked out to 0.3 gallon of gas per hour or a maximum total idle time of 51.8 hours, or just over two days, based on its 15.9-gallon tank.
Converting these consumption figures to equivalent energy units shows an electric vehicle’s dramatic advantage in efficiency, with the Model 3 consuming 1.6 kWh per hour and the Sonata using more than six times the energy at 10.3 kWh per hour. That’s no surprise, as the Tesla is able to run only its HVAC system and just enough to keep the cabin at our 65-degree set point, while the Sonata has to keep its 290-hp turbo-four humming inefficiently at idle to run the climate control.
While that last paragraph seems to hand victory to the electric vehicle, it was the gasoline-dependent Sonata that was on pace to have the longer maximum total idle time. But there are loads of other factors to consider, starting with temperature.
Car and Driver explicitly stated that the vehicles were being tested in a survival scenario with a targeted interior temperature of 65 degrees. That’s great for the Tesla, which would have had to use more of its energy reserves to maintain higher cabin temperatures. But it makes little difference to the heater core found in the Hyundai because all it’s doing is reallocating excess engine warmth. In fact, a higher targeted interior temperature probably would have made the Sonata more efficient overall. Testers also acknowledged that the Model 3 would have had to exert substantially more energy to maintain the cabin’s climate if exterior temperatures were colder, whereas the Hyundai wouldn’t.
With the Sonata on pace to outlast the Tesla by several hours, keeping the hypothetical occupant warmer while stranded, it seems like the clear winner here. However, Car and Driver attempted to temper the results by mentioning how EVs tend to be charged overnight while gasoline-reliant cars tend to fill up only when convenient — which is probably accurate but also kind of like losing a boxing match and then suggesting the results would have been different if you had jumped your opponent on the street. Though in a real survival situation one wouldn’t even be running a combustion vehicle full time. They’d only have the engine turning sporadically to ensure adequate warmth, saving as much fuel as humanly possible the rest of the time.
Considering testers could have easily selected an internal combustion vehicle with a larger fuel tank or an EV that’s less adept at holding its charge in freezing weather, it’s kind of hard to know what to do with this information. With no noxious gasses to monitor, it’s probably far more comfortable to be stuck in an EV when it’s cold and there’s literally nowhere to go. But it seems like battery densities will need to continue coming up before electrics become the better option when an occupant’s survival is on the line in a true worst-case scenario.
Unless they forget to fill up the tank, that is.
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