48-Volt Mild Hybrids Rise in Europe as Diesel Fade

European carmakers are rushing to offset fading sales of fuel-saving diesels with cheaper 48-volt “mild” hybrids that deliver similar efficiencies, Reuters reports.

The 48-volt systems consist of a more powerful starter motor and small storage battery. The package provides brief assist to a piston engine, notably during acceleration.

Market analysts Evercore ISI predicts that 55% of new cars sold in Europe by 2025 will be equipped with 48-volt mild hybrid systems.

A major appeal is that the technology can be added to an existing powertrain with almost no modification. The systems offer fuel savings of about 15%, and their manufacturing costs are at least €500 ($600) lower than those of diesels that offer similar mileage gains.

Mercedes-Benz, Renault, PSA and Volkswagen have been quietly adding 48-volt mild-hybrid systems to European models to offset the impact of slumping diesel sales. Manufacturers are making the move to meet an EU requirement that they reduce average carbon dioxide emissions from new cars to 95 grams per kilometer by 2021 from 130 g/km today.

Carmakers also are developing a flood of plug-in hybrids and all-electric cars to bolster their fuel efficiency averages. But Reuters note that those models won’t arrive in sufficient numbers soon enough to help with the 2021 deadline.