If drivers want to switch away from a completely gas-powered car to something electric, they have a few options. Namely, battery electric vehicles, hybrids, or plug-in hybrids (PHEVs).
All are seen as a way to reduce transportation emissions and move away from gas-guzzling internal combustion cars.
But it turns out that plug-in hybrid owners may not actually be plugging in their vehicles, making PHEVs not quite the environmental solution that they would appear to be.
General Motors CEO Mary Barra, speaking this week at the Automotive Press Association conference in Detroit, touched on this reality when she discussed GM’s plans for electric and hybrid vehicles.
“What we also know today with plug-in hybrids is that most people don’t plug them in,” Barra said. “So that’s why we’re trying to be very thoughtful about what we do from a hybrid and a plug-in hybrid perspective.”
Hybrids as a solution to EV sales growth
EVs are seen as a crucial climate solution. In the U.S., transportation accounts for the largest source of greenhouse gas emissions, and switching to electric vehicles cuts those emissions and reduces air pollution.
The recent growth in EV sales meant that transportation emissions stayed relatively flat in 2025, despite an increase in road traffic (and an increase in electricity emissions at large).
But the rate of that sales growth has been slowing, and is expected to slow even more in 2026, in part because the Trump administration ended federal subsidies that helped people purchase EVs.
With the end of those tax credits, plus tariffs and bad consumer sentiment tainting EV sales, automakers have looked to hybrids as a way to still get customers into more efficient cars.
GM is one of those automakers. In 2024, the company said it planned to bring plug-in hybrid options to North America in 2027.
At the conference this week, Barra said that while GM is enthusiastically investing in EVs “because we think that’s the endgame,” the automaker is still “continuing to evaluate” hybrid and plug-in hybrids.
Plug-in hybrids don’t need to be plugged in
If drivers aren’t plugging in their plug-in hybrids, though, then that vehicle option isn’t as helpful for the climate as it seems.
There are two main types of hybrids: HEVs, or hybrid electric vehicles, which use regenerative braking to recharge the battery, and PHEVs, or plug-in hybrids, which can be plugged in just like an EV to charge. (PHEVs also allow regenerative braking to charge the battery—just by a smaller amount.)
But plug-in hybrids don’t need to be plugged in to work. Plugging those vehicles into an EV charger will make them more efficient, and can allow drivers to avoid using their gas engine at all. However, they can still be driven without a charge and rely solely on gas.
Doing so could make plug-in hybrids even less fuel-efficient than gas-only cars, according to Consumer Reports.
“For example, once the BMW 330e xDrive sedan’s 20-mile electric range is exhausted, it only gets 25 mpg—3 mpg less than the conventional 330i xDrive’s EPA rating of 28 mpg,” per the outlet.
That’s likely because a plug-in hybrid’s battery increases the vehicle’s overall weight, making them less fuel-efficient. (Because of their batteries, electric vehicles are heavier than gas-powered cars.)
The climate reality of plug-in hybrids
So, are plug-in hybrids’ climate benefits actually overblown? Research says yes.
An October 2025 report from Transport and Environment, a European advocacy group for clean transportation, found that plug-in hybrids are “a diversion on the road to zero emissions.”
The real-world carbon dioxide emissions of plug-in hybrids, the report found, are nearly five times the ”official” emissions estimates.
European Commission driving data released in 2024 came to a slightly different conclusion, but showed the same trend: Plug-in hybrids produce about 3.5 times the official emissions determined in lab tests for regulatory purposes, that report found.
Basically, regulatory assessments to determine emissions assume that 84% of PHEV drivers operate their vehicles primarily with the battery. In reality, only about 27% do so.
Data on U.S. plug-in hybrid drivers shows the same issue.
A 2022 report by the International Council of Clean Transportation found that for plug-in hybrids in the U.S., “real-world electric drive share may be 26% to 56% lower, and real-world fuel consumption may be 42% to 67% higher than assumed within the EPA’s labeling program for light-duty vehicles.”
How efficient, and helpful to the environment, that plug-in hybrids really are, then, depends on their drivers. That’s why environmental experts—and even Barra herself—say that EVs are still ultimately the endgame for the auto industry.