The PSA Peugeot-Citroen Group is expecting to have fuel saving stop-start technology in 1.9 million vehicles in Europe by 2014.
That's almost four times the number which next up Fiat proposes, at 540,000.
Daimler will be next in numbers, at a planned 350,000, followed by VW with 200,000, GM Europe with 140,000 and Ford with 70,000.
Meanwhile, Renault has done an about-turn on the technology and is actively evaluating the products of a number of suppliers, with a view to making it available across its whole range.
Stop-start is estimated to cut emissions by up to 20 percent in city driving.
