Yet, the CLS63 AMG is far from the only AMG model (and in turn, the Mercedes-Benz model) to feature a stop-start system, and it's that dogged obsession with the fuel-saving technology that's earned Mercedes a credit on the EPA's fuel-economy standards. These so-called "off cycle" credits are awarded when manufacturers might come up with an efficiency improvement that doesn't necessarily show up in the EPA's testing cycle.
The credits are a big deal for Mercedes-Benz which, according to Automotive News, shelled out $349 million for missing government fuel economy standards last year. While the German manufacturer was awarded credits for its use of stop-start, the total credits were lower than requested, AN reports. That's because the EPA was unsure of how often the system would be used in the real world, a long-standing problem.
Mercedes could still get its way, though, as the EPA has requested additional data on the systems. "There is a real savings here, and we have been able to definitively prove it," Daimler AG's manager of regulatory affairs, William Craven, told AN.