Plug-in hybrid vehicles are often touted as a bridge to battery electric vehicles, promising to reduce emissions by operating as EVs for short journeys and relying on fossil fuels for longer journeys.
It only fulfills its promise if you are billed regularly. Real-world data extracted from vehicles’ on-board computers shows that this is often not the case.
Using that data, the Fraunhofer Institute was able to determine how much of that energy comes from a charge when plugged in. They found that less than a third of Germany’s 1 million PHEVs plug in only sometimes or not at all.
U.S. automakers should take note as they promote future PHEV models as attractive options for U.S. drivers. By blending gas and electricity, these automakers hope to improve overall fleet efficiency without widespread EV deployment.
“We’re looking to reduce carbon emissions across our lineup, and we’re doing it in a very efficient way,” Ford CEO Jim Farley said on an earnings call this month.
However, new research shows that PHEVs barely achieve the expected efficiency.
At best, Toyota drivers derive 44% of the energy they use to drive from electricity, meaning they are most often plugged in. worst? Only 0.8% of Porsche drivers averaged 7 kilowatt-hours over two years. In other words, the average Porsche PHEV driver charges less than 50% of the battery capacity at any one time.
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Previous studies have shown that PHEVs produce emissions approximately 3.5 times higher than their official ratings. This new study explains why, as it directly assesses how much power a vehicle gets from charging. (PHEVs, like all hybrid vehicles, can operate in a mixed mode using both gas and electricity. This study used data directly from the vehicle to understand the two.)
One of the many drawbacks of PHEVs is that the batteries that can power the vehicle for short distances are anemic. Some can only go for a few miles, but many sold these days can go about 20 to 30 miles on battery power. European regulators and automakers have proposed extending the range of future models in the hope that higher-performance batteries will encourage people to charge their batteries more often.
However, this is not guaranteed. Vehicles can still be at risk when driving electronically. That’s because most PHEVs are based on fossil fuel platforms, where the electric motor and power electronics cannot supply 100% of the vehicle’s power needs. When the driver places the car on the floor, the gasoline engine must start. In other vehicles, the engine runs in cold weather to warm the cabin. In that case, the question most PHEV drivers seem to be asking themselves is, “Why bother plugging in?”
This brings up another question: why bother with PHEVs?
PHEVs have been touted as a way to ease cautious consumers into going full EV. The argument goes like this: As EV charging networks are built out, drivers will become accustomed to plug-ins. By the time the next car is ready, the network will be ready and customers can step into their EV with confidence.
But if no one plugs in a PHEV, you definitely won’t get into the habit. Without a full charge, an electric drivetrain won’t benefit anyone. The nation continues to suffer from worsening air pollution. And drivers carry hundreds of pounds of weight and endure increased recalls and repair costs due to complex drivetrains.
Tweaking the PHEV formula to make it more reliant on batteries could help. The interim solution is called an extended range electric vehicle (EREV) and is designed to run on battery power until it runs out of charge, at which point it is recharged by a fossil fuel engine. So far, there are no EREVs that owners don’t have to plug in. It can easily run on gasoline for the lifetime of the vehicle. BMW used to make an EREV for the i3, but they discontinued it a few years ago. Ford and Stellantis have both announced EREV pickup trucks, but none have been released yet.
Meanwhile, EV charging networks continue to expand. By the time automakers produce PHEVs and EREVs in large numbers, drivers may no longer need the comfort blanket of a gas engine. (My family came to that conclusion two years ago. After a 10-year split between a BMW i3 EREV and a Chrysler Pacifica Hybrid PHEV, we traded in for a Kia EV9.)
Legacy automakers have reconsidered their electrification strategies more times than I can count, and they may be forced to change course again.
PHEVs may have been a nifty solution on paper, but they never materialized in the real world.
