Stop/start shuts down the engine in certain driving conditions to reduce fuel consumption. The technology is becoming more prevalent worldwide.
The 2.5L Impala with stop/start yields an EPA-estimated fuel economy of 22 mpg city, 31 for the highway and 25 combined. The Impala with the 3.6L V-6 engine will not include stop/start technology.
The Impala becomes the second vehicle in Chevrolet’s U.S. lineup to feature stop/start technology, following the segment-first standard inclusion in the 2014 Malibu introduced late last year. The technology helps improve the Malibu’s city fuel economy by 14%.
Chevrolet engineers developed the stop/start in the Impala from extensive experience with GM’s eAssist system and the accompanying algorithms that allow engines to engage and disengage subtly.
Worldwide sales of vehicles with stop/start technology will grow from 8.8 million in 2013 to 55.4 million in 2022.
A big challenge for the team was overcoming “change-of-mind events,” instances in which the driver begins to stop, but then quickly accelerates. The algorithms adapt the system so the starter can fire even if the engine did not fully shut off.
The smart software also prevents the system from engaging if the car does not reach 6 mph since its last start, a welcome feature in stop-and-go-driving conditions. The system also considers cabin temperature, humidity, battery charge and other factors when deciding if the engine should come to a stop.
The team included a larger heavy-duty starter motor to assist with the additional ignition cycles.
The 2015 Impala goes on sale this summer with a suggested starting price of $27,735 for the 4-cylinder LS model, and $30,960 for the 6-cylinder LT model. These include an $825 destination charge, but exclude tax, title, license and dealer fees.