A new study found that they emit way more carbon than regulators estimated.
Plug-in hybrid electric vehicles (aka PHEVs) are a popular choice among those who want to reduce their carbon footprint but are not yet ready to make the full commitment to all-electric vehicles.
But a previous assumption by regulators like the European Union that PHEVs emit 75% less carbon than gasoline and diesel-dependent cars is actually false, according to researchers from Brussels-based non-profit Transport & Environment who studied hundreds of thousands of cars registered in Europe between 2021 and 2023.
In a new study published on Thursday, the researchers claim that plug-in hybrids actually only emit 19% less than cars with internal combustion engines.
“I think it’s quite a scandal to have this gap between real world and official data,” one of the co-authors of the study, Yoann Gimbert, told Gizmodo.
That gap has also been widening over the years. In 2021, PHEVs actually emitted 3.5 times the official emissions estimates. By 2023, that number was nearly five times.
There are several reasons why this could be the case, according to Gimbert.
The first is that plug-in hybrid owners, at least Europeans, might not be using the cars in their intended way. Both plug-ins and standard hybrids rely on both an electric motor and an internal combustion engine. But, unlike standard hybrids, plug-in hybrids have a larger battery. As the name suggests, this allows them to be plugged in to charge externally and to drive some distances while relying entirely on the electric motor.
Gimbert said that European drivers might not be incentivized to drive it fully in electric mode.
