FRANKFURT -- Automakers squeezed between carbon emissions cuts and falling sales of fuel-efficient diesels used the Frankfurt auto show to spotlight a future generation of electric cars that will largely come too late to help them out of their bind. But elsewhere at the show, suppliers such as Valeo and Delphi lifted the lid on a quicker fix: affordable 48-volt hybrids.
These "mild" hybrids, which add some electric power to existing gasoline models without a costly redesign, are now being deployed without fanfare by brands including Volkswagen, PSA, Mercedes-Benz and Volvo.
It is diesel's decline, executives and analysts say, that has finally set the stage for mass electrification. While diesel pollution problems became notorious with the Volkswagen test-cheating scandal, the subsequent shift to gasoline is bloating carbon dioxide (CO2) emissions, making the next round of European Union goals harder to meet.
"Our view is that 48 volts on a gasoline engine is an alternative to diesel," said Karin Thorn, vice president for vehicle propulsion at Volvo. "If and when the diesel market is dropping, something else needs to take its place."
Diesels are stalling already, in fact - and weaker second-hand values suggest the slump can only accelerate.
An attention-grabbing pledge by Volvo to "electrify" its entire range by 2019, initially hailed as a bold step, now looks more like an industry-wide reality.
PSA Group, which had previously seen no need for 48V hybrids, now plans to introduce them "across the board" in response to diesel's faster-than-expected decline, the Peugeot maker's programs chief Patrice Lucas told Reuters.
By quadrupling the 12-volt standard in conventional car electrics and allowing a beefed up starter motor to feed extra power to the drivetrain, complementing the combustion engine, carmakers can transform gasoline cars into mild hybrids without redesigning the vehicle's architecture and factory tooling.
The motor delivers a noticeable torque boost and recovers braking energy to recharge a battery - smaller and cheaper than those required by electric cars or "full" hybrids such as Toyota's Prius, which typically run at 100-300 volts. Total manufacturing cost comes in 500-1,000 euros ($600-$1,200) below an equivalent diesel.
"It's the most interesting enabling technology and will comfortably replace diesel," said Evercore ISI analyst Arndt Ellinghorst. "It can do the job and it's already cheaper - you don't have to be an early adopter to buy one."
By 2020, the brokerage expects 48V cars to outpace European sales of full hybrids, including plug-ins that can be recharged with a cable and driven in electric-only mode. By 2025, it predicts, they will equip 55 percent of all cars sold.
The technology is surfaced in luxury cars such as the Mercedes S class on show at the Frankfurt event and is trickling down to the mass market, chiefly in Europe and China.
Volkswagen's next Golf, a benchmark in compact cars, will arrive with 48V electrics in 2019, and other models will follow, development chief Frank Welsch told Reuters. "The technology has a lot of potential and will make hybrids more affordable for the masses," Welsch said.
Renault was among early adopters of 48V hybrids, with a system supplied by Continental for its Scenic and Megane cars. Nissan and Hyundai are among other mass car manufacturers with 48V in the pipeline.