Mazda recently introduced a new regenerative braking system that powers the car’s electrical functions as the vehicle brakes. The system is called i-ELOOP — or “Intelligent Energy Loop.” It makes an internal combustion vehicle behave in a manner similar to a hybrid.

Converts kinetic energy to electricity

The system converts kinetic braking energy — usually lost to heat in the brakes — into electricity. That electricity is then sent to an Electric Double Layer Capacitor, or super-capacitor, for storage.

i-stop system turns engine on and off

When the car comes to a complete stop, the Mazda-branded “i-stop” system automatically shuts the engine off, conserving fuel. The auxiliary electrical functions — such as the sound system, heating, a/c and lights — then run off of the electricity stored in the super-capacitor. The engine then automatically restarts when the accelerator is depressed.

Improves fuel economy by 10 percent

The system is likely to be most efficient in stop-and-go city driving. According to a Mazda press release:

“In real-world driving conditions with frequent acceleration and braking, ‘i-ELOOP’ improves fuel economy by approximately 10 percent.”

Possible downside?

“Car and Driver” points out that an argument against the system could be that super-capacitors can only store electricity for a short time, and also discharge that power very quickly. However, the same article points out that the super-capacitor can be charged in seconds. Also, super-capacitors have great longevity and will likely never need replacement. The same is not true of batteries.

Similar to BMW’s EfficientDynamics system

The system is similar to the BMW EfficientDynamics system in that it stores power generated while braking. However, the BMW uses a more costly glass-mat battery instead of the capacitor.

Available in 2012

Mazda plans to begin introducing the system in its new cars next year.