Scientists have run the numbers, and the result isn’t exactly a pat on the back for the internal combustion engine. A study published in Science shows that replacing a functioning gasoline car with an EV cuts lifetime carbon emissions by 58%. Even if that gasoline car is only a year old. Also, the old “drive it until it dies” argument is more myth than reality.
The logic seems sound. Manufacturing an EV produces more CO2 than building a combustion car. So why not squeeze every last kilometer out of the old ICE companion before switching?
Because the operating savings are so enormous that they swamp the manufacturing penalty within about three years. After that, every kilometer driven in the EV is pure climate profit.
‘Obvious winner’
Elliott Campbell, environmental studies professor at UC Santa Cruz and lead author, puts it plainly: “Even in such an extreme scenario, the EV is still the obvious winner.”
His co-author, Roland Geyer, an industrial ecologist at UC Santa Barbara, adds that replacing a combustion vehicle with a battery-electric one “almost always reduces greenhouse gas emissions.”
The study modeled more than 400 vehicle combinations across the US market, accounting for grid mix, battery size, manufacturing emissions, vehicle class, and mileage. In 92% of scenarios, early retirement of the ICE car and its replacement with an EV resulted in a net emissions reduction. Case closed then? Not entirely.
Two exceptions
The phrase “almost always” translates into two categories of drivers who should stick to ICE. First, plug-in hybrid owners. Because PHEVs already cover a chunk of their miles on electricity and carry smaller batteries, the manufacturing hit of a full BEV can outweigh the gains in some cases.
Secondly, the annual mileage plays a decisive role. The study found that cars driven fewer than 7,054 km per year (half of the Belgian average), SUVs under 6,837 km, and trucks under 10,794 km do not generate enough operational emissions to justify the production footprint of a new EV. But for everyone else, the switch is a no-brainer.
Europe looks even better
The study used US data, where the grid is dirtier, and Americans drive more miles. Still, for Europe, the case is stronger. European grids carry a larger share of renewables, and the EU’s electricity mix is decarbonizing faster than the US average. The break-even point of roughly three years would likely shorten on our side of the Atlantic.
Kenneth Gillingham at Yale University called the paper’s angle “clever” and the conclusion “perfect sense.” Gregory Keoleian at the University of Michigan cautioned that scrapping a one-year-old car is an “extreme case” that most consumers will not do. But the point is that they could, and the climate would still win.
The paper’s main message is that hesitation is not climate-friendly. The “keep driving it” crowd has been wrong all along.
