Toyota’s Chief Engineer Satoshi Ogiso figures that efficiency improvements of traditional gasoline engines may soon hit a wall. He gives the gasoline engine an improvement potential of “maybe 10 to 20 percent.” Today, we have proof that it is a fight of diminishing returns. Mazda is now at a point where it saves up to 10 percent of gas by idling the alternator. How is that done?
Mazda’s developed a regenerative braking system that uses a capacitor. Compared to batteries, a capacitor can be charged and discharged rapidly. Also, it does not wear out like a battery. Mazda stores the regenerated energy in the capacitor. It does not use it to power the car. That would need a hybrid system Mazda does not have. Also, even the new Electric Double Layer Capacitor (EDLC) Mazda uses would not get you far. Instead, Mazda uses the electricity to power the climate control, the audio system and other gizmos in the car that want electric power. As we know, the gizmos proliferate with abandon. And why does that save gas?
The electric power generated by the car’s alternator does not come free. The alternator demands power from the engine. As a rule of thumb, 5 hp are usually used, however, this changes with the amperage and type of the alternator.
Mazda calls its system “i-ELOOP.” It comes from “Intelligent Energy Loop.
The system uses a new 12-25V variable voltage alternator, a low-resistance electric double layer capacitor and a DC/DC converter. ‘i-ELOOP’ starts to recover kinetic energy the moment the driver lifts off the accelerator pedal and the vehicle begins to decelerate. The variable voltage alternator generates electricity at up to 25V for maximum efficiency before sending it to the Electric Double Layer Capacitor (EDLC) for storage. The capacitor can be fully charged in seconds. The DC/DC converter steps down the electricity from 25V to 12V before it is distributed directly to the vehicle’s electrical components. The system also charges the vehicle battery as necessary. Says Mazda:
“As a result, in ‘stop-and-go’ driving conditions, fuel economy improves by approximately 10 percent.”
The system will begin to appear in Mazda vehicles in 2012.
Mazda does not have hybrid technology and instead is betting on optimizing the ICE with Mazda’s Skyactiv Technology and other fuel saving tricks. As we see, the engineers have to get very creative to save a few more drops.