High European demand for Citroën's class-leading HDi Diesel engine, fitted to the Xsara, Xsara Picasso, Xantia and Synergie plus the company's commercial vehicles, means that engineers at the Citroën factory at Tremery in France are now working flat out seven days a week. In stark contrast to stories of surplus production elsewhere within the industry, the Citroën plant is currently operating 24 hours a day throughout the week, plus Saturdays and Sundays. With production levels already reaching 7,000 engines a day, it is planned to increase output by a further 1,000 units per day by the end of the year.