Idle-stop will take off, says Bosch
BY JAMES STANFORD | 16th Mar 2009
Bosch is confident the fuel-saving technology, also known as a micro hybrid system, is a crucial middle step between combustion engine cars and more advanced hybrid models and will soon be picked up by most manufacturers.
Idle-stop switches off a petrol engine when the vehicle comes to a halt and re-starts it when the driver is ready to move off.
It has been introduced by a long list of brands in Europe, including Toyota, Citroen, Fiat, BMW, Hyundai, Mazda, Kia, Mercedes and Volkswagen, but the feature is not yet available on any cars in Australia.
This will change when the Mini Cooper D, a diesel model that uses just 3.9L/100km, is introduced locally in May.
Bosch automotive electronics senior vice-president Dr Hans-Peter Huebner, who visited Melbourne for the SAE Change by Design conference earlier this month, is convinced idle-stop will quickly spread across the industry.
He said it was a relatively inexpensive way for car-makers to reduce the fuel consumption of their vehicles, helping to meet emission targets and appease customers.
“We believe we will have a very high penetration with this,” he said.
“You can save fuel easily with this system, also from a social perspective using fuel when an engine is just idling and not providing any value.”
Dr Huebner said his company was confident 85 per cent of new cars sold in Europe in 2014 would use the system, with other regions to follow.
He said initial idle-stop systems had drawbacks including fluctuations on re-start that could momentarily dim the lights and cut the radio, but said a recent DC converter advancement, as introduced on the European BMW 1 Series, had cured that problem.
Dr Huebner said the current idle-stop systems, linked to an effectively standard lead acid battery, would help reduce fuel consumption but would not be able to draw a charge from the engine and brake like existing hybrids.
“If you want to do some recuperation, a system like this will not be very efficient due to the nature of the battery as a lead acid battery is very reluctant to take energy in a short time and therefore you would need other storage possibilities,” he said.
Dr Huebner said Bosch was working on several advanced components for hybrid, teaming up with Samsung to draw on its battery knowledge.
He said plug-in hybrids with combustion engine range extenders would be the next step before the automotive industry moved on to full electric vehicles depending on battery capacity and whether fuel cells can be made reliable and affordable.
Dr Huebner said it was not clear when full electric vehicles will be widespread.
“It is very difficult to predict when it will come,” he said.
He added that while fully electric cars appeared to be gaining momentum, significant take up of the technology would not happen overnight.
“It might seem like pure electric is not far away, but from our point of view it will not come tomorrow – there is still a long way to go,” he said.
Dr Huebner said there was life left in petrol and diesel engines which could be made significantly leaner.
“There is still a long way to go with the combustion engine,” he said.
Fuel saving improvements would include smaller capacity with turbo or supercharging, cylinder deactivation, variable valve actuation, improved ignition control, direct injection, better exhaust gas treatment including recirculation and better transmission controls.
Dr Huebner said there would also be savings to be had with electric control of some engine auxiliary systems such as cooling fans and pumps.
He pointed to the example of replacing hydraulic power steering assistance systems with electric systems, adding that this switch also brought other benefits such as parking assistance systems.
Thanks to improved control, electric assisted steering systems have been developed to help park the car with limited input from the driver (such systems are now available on a handful of prestige models in Australia).
“On one side you have the fuel saving benefits 0.3L/100km and you also have the opportunity to introduce innovations,” he said.
Bosch predicts petrol and diesel engines will still dominate sales around the world in 2016. Its data suggests hybrids will grow, but will not outsell ethanol flex fuel and LPG/CNG in Europe and the US.
Bosch predicts hybrids will grow faster in Asia, which will have close to no interest in ethanol.
Customers are not about to give up combustion engines, said Dr Huebner.
“Combustion engines will stay for a long period because most of the people like to have them,” he said.