Why Not Start and Stop?

A Mazda executive is blaming the EPA's testing for the lack of stop-start technology spreading here in the US. Despite it's popularity overseas and the ability to save 7% in fuel for a very small price tag, the start-stop technology has not made a significant dent in the market. (Source: AutoNews).

According to the Mazda exec, Robert Davis, the EPA testing which creates the figures shown on the MPG sticker will show very little change in the car's fuel economy.

And so, car makers are very reluctant to put the start-stop into cars when the EPA is going to say it doesn't really do anything. Customers just aren't going to believe dealers when they say, "No, really, this does something" when the sticker doesn't show it.

In case you're wondering, start-stop technology turns the engine off when the car is stopped or decelerating. It then restarts the engine when you step on the gas pedal. It's found in full and mild hybrids, but hasn't made a dent in more conventional cars.

The EPA testing includes only one complete vehicle stop, which results in a 0.1 or 0.2 mpg improvement according to Davis. Customers aren't going to want to spend $500 more for a technology that's just going to give them back so little. But Davis points out in real world driving, you could see a 7-9% increase in fuel economy.

The article points out that Mercedes, Audi, Mazda, Volkswagen and others all offer start-stop technology elsewhere. And if the EPA changes its rule development, we could see it here in the US.