Engine Stop-Start Systems

Is a Stop-Start Vehicle Right for You?

Automakers today face a big challenge – how to build more fuel-efficient vehicles that will be loved by consumers. One recent answer to this conundrum is engine stop-start systems that let motorists drive the cars they like while reducing fuel consumption and exhaust emissions.

Stop-start technology is common on hybrid vehicles, but has only recently emerged on non-hybrids. The system shuts down the engine when the vehicle is at a complete stop − such as in traffic or at a stoplight. As soon as the driver releases the brakes or depresses the clutch pedal, the engine restarts automatically. While the engine is stopped, electrical accessories are powered by the vehicle’s battery.

Stop-start technology can be added to a traditional vehicle powertrain for about $300, making it more affordable than many other fuel saving technologies. And, with estimated annual fuel cost savings of around $167 (more than 12,000 miles in a vehicle that averages 20 mpg), stop-start systems can pay for themselves in less than two years.

One issue may be the special high-capacity battery required in a stop-start system. This type of battery is necessary to handle the added electrical loads, but costs nearly twice as much as a traditional battery.

Stop-start systems are carefully engineered to smooth engine off/on transitions, but drivers new to the technology may be disconcerted by the lack of engine noise when stopped. Also, heater and air conditioning performance may suffer if the engine remains shut down for an extended time.