Chrysler says it has sold more than 1 million vehicles equipped with its TorqueFlite 8HP45/845RE 8-speed automatic transmission, first installed in the ’12 Dodge Charger and Chrysler 300.

The rear-wheel-drive gearbox is used in 19 ’14 Chrysler vehicles across four vehicle segments, including the Dodge Durango, Ram 1500 and Jeep Cherokee lineups. Starting in ’15, it will be paired with Hemi-equipped Dodge Chargers, Challengers and Challenger SRTs.

Over the lifetime of the vehicles equipped with the advanced transmission, owners are expected to save more than 700 million gallons (2.6 billion L) of fuel compared with their predecessors with 5- and 6-speed gearboxes, the automaker says.

That quantity of gasoline is worth about $2.5 billion based on current fuel-price forecasts, Chrysler says. The transmission also will reduce combined carbon-dioxide emissions more than 6.6 million tons (6 million t).

“This is precisely the kind of impact we target with the TorqueFlite program,” Jeffery Lux, vice president and head of transmission powertrain, says in a statement. “And we fully expect this momentum to continue as we expand availability.”

The transmission is produced under license from supplier ZF Friedrichshafen at Chrysler’s Kokomo, IN, plant. The automaker also uses ZF’s 9-speed automatic transmission.

bpope@wardsauto.com