MADISON, Wis. – So, what do you know about stop-start technology? Ever driven a stop-start car?
Probably not. Neither have I. But a recent conversation with Cecilia Smith at Texas Instruments got me interested. Smith is vice president of the Mixed Signal Automotive (MSA) part of TI’s High Volume Analog and Logic business.
The idea behind stop-start seems quite straightforward. The system automatically switches off the engine when the car is at a standstill and restarts it as soon as the driver presses the clutch pedal or releases the brake.
Imagine your car stuck in a traffic jam or waiting at a traffic light. The ability of a vehicle to automatically stop its engine when stationary and then fire up again when it’s time to move could lead to significant fuel savings and reduction in vehicle emissions, according to Navigant Research.
Stop-start vehicles, in fact, might be finally coming our way, in volume, over the next several years. In its recent report Navigant Research forecasts that total global sales for light-duty stop-start vehicles will exceed 55 million by 2022, accounting for 54.3% of total vehicle sales.
Of course, today the reality is much different.
The stop-start market share in the United States in 2012 was one percent, compared to Europe’s double-digit percentage, according to a report by SAE International, formerly the Society of Automotive Engineers.
So, what’s stopping carmakers from going big on stop-start vehicles -- especially in the United States?
One nagging issue is the lag time between stop and start. Carmakers are worried that driver impatience (or the Jackrabbit Syndrome) might just kill the US consumers’ appetite for stop-start technology.
A case in point is a Honda’s decision earlier this year. The Japanese carmaker decided to drop stop-start technology for the US market in its Honda Fit when it’s launched in the US market in 2014.
Automotive News reported last September:
The fuel-saving technology, which shuts off the engine at stoplights, is popular outside North America. In Japan it comes standard on all versions of Honda's new Fit small car.
But the lag between stop and start makes it slow off the line. That’s partly why engineers chose not to apply it to US-bound cars.
Nobuhiko Shishido, a lead powertrain engineer at Honda for the new Fit, said that in the United States, where speed and power rule, stop-start systems mean small cars will be left in the dust.
But exactly how long is this lag we’re talking about? Three seconds? Five seconds? ‘Til next Thursday?
Well, no. Shorter than that.