Small Solutions to Greater Fuel Efficiency: Stop Idling, Manage Air Conditioning

March 30, 2007 – Vol.12 No.1

SMALL SOLUTIONS TO GREATER FUEL EFFICIENCY:
STOP IDLING, MANAGE AIR CONDITIONING.

President Bush this week continued to promote his Twenty in Ten goal: Reduce America's gasoline consumption by 20 percent over the next 10 years.

In their bid to help out, the US Postal Service, UPS, FedEX and Washington DC’s Metro transit system showed their offerings to the President; hybrid trucks and buses, biodiesel, natural gas and fuel cell vehicles. Ford put its concept Edge Hy-Series Hybrid hydrogen/electric SUV on the White House lawn for Presidential viewing along side a flex-fuel Chevrolet Impala from GM and a biodiesel-fueled Jeep Grand Cherokee from DaimlerChrysler.

Twenty in Ten includes increasing the fuel economy of cars and setting a mandatory alternative fuels standard to require 35 billion gallons of renewable and other alternative fuels be sold each year by 2017.

Automakers are resistant to an increase in fuel economy of only 4 percent per year, but have no problem building more ethanol-capable flex-fuel cars since it costs only $100 per car to do so.

Yet could a relatively small technological change offer as much as an eight percent increase in fuel economy? According to the Robert Bosch Corporation, sure, change the conventional starter motor to a stop-start system.

With stop-start the engine shuts off when the vehicle comes to a stop. The engine won’t idle when the vehicle is at rest. A touch of the gas pedal brings the engine to life, ready to accelerate.

Hybrids already have this feature and it’s considered one of the reasons hybrids get better fuel economy than their conventional counterparts. With stop-start any vehicle could realize the fuel savings.

Bosch says that the more robust starter motor it supplies for the system, along with electronics to manage battery power, ensures that the engine starts reliably, quickly and quietly.

In the US, an act of Congress, or perhaps a ruling by the US Environmental Protection Agency (EPA), could make stop-start systems standard vehicle technology by banning vehicle idling.

Bosch's stop-start system will be standard equipment on the BMW 1-Series which is rumored to make it to US shores for the 2008 or 2009 model year.

The company also says that fuel savings of up to 10 percent is possible with better management of vehicle air conditioning systems.

Bosch has created a new sensor that monitors the level of carbon dioxide in a vehicle’s cabin. When fresh air is fed into the passenger compartment the air conditioner switches into the fuel-saving air recirculation mode. After a time, when the sensor detects high levels of CO2 from occupants, the air conditioner switches out of recirculation mode back to outside air intake mode just long enough to replace stale air. The cycle then repeats itself.

Fuel savings would be realized only when the vehicle’s air conditioning system is in operation, which is often in some climates and in vehicles with full climate control systems.

Typically air conditioning systems can reduce fuel economy up to 20 percent in urban or stop-and-go driving. The Bosch technology would give back some of that wasted fuel.

Visit Bosch Group US at http://www.bosch.us/