Depending on your point of view, the future for mild-hybrid systems could be either exceedingly dim or unexpectedly bright.
Vehicles that employ them use electrification to a lesser extent than conventional hybrids, to provide a small boost of power or to power electrical accessories--but not to travel on electricity alone.
A few years ago, General Motors bet that mild hybrids would soon account for a large portion of its green-car sales. So far, that hasn't happened.
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But suppliers believe mild-hybrid systems could be key to helping improve the fuel efficiency of a larger share of vehicles, under the shadow of increasingly stringent carbon-emissions and Corporate Average Fuel Economy regulations in place around the world.
One of those suppliers is Bosch, which has developed a system that it calls the "hybrid for everyone," according to Charged EVs.
This setup is based around a 48-volt electrical system, with a small electric generator that can assist the engine with up to 10 kilowatts of power, and a tiny lithium-ion battery pack.
2015 Buick LaCrosse
Bosch says the system can increase fuel efficiency by 15 percent, as well as provide "more dynamic" acceleration.
A converter also supplies electrical power to a car's standard 12-volt system from the 48-volt hybrid system.
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Bosch claims a mild-hybrid approach allows for the use of less-expensive components, which means its systems could be installed in vehicles at a wider range of prices.
With added ultrasonic sensors, the company even claims this system could enable automated parking.
2013 Acura ILX Hybrid, New York City, July 2012
Without offering much in the way of specifics, Bosch says a version of the mild-hybrid system could allow cars to steer themselves into parking spaces.
There are even provisions for vehicles to be potentially manipulated remotely via a smartphone app, the company claims.
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While mild hybrids haven't proven to be much of a sales success so far, it's possible carmakers will build more of them in response to stricter emissions standards.
They could potentially serve as a half-step between engine start-stop systems and more complex and expensive full hybrids, which provide electric-only travel for up to a mile or two under low loads.
Bosch expects roughly 4 million new vehicles worldwide to be equipped with its new mild-hybrid system by 2020.