A guide to the latest fuel saving technologies

Auto engineers have developed many different technologies in the last decade to reduce your car’s fuel consumption.

With the plethora of advances made in the last few years or so, there is now a befuddling amount of technology that you can find in even some inexpensive compact cars.

In this article, we’ll be taking a brief look at the major systems offered today.

Hybrid technology

Micro hybrid – Up to 5% savings in fuel consumption

Better known as a start-stop system, a micro hybrid system can provide for a 5% efficiency bump. This system automatically stops the internal combustion engine to reduce idling time at red lights, thereby reducing fuel consumption.

In most vehicles equipped with a start-stop system, an enhanced starter and deep cycle battery is fitted so as to be able to withstand the increased numbers of engine starts. Other setups include an enhanced combined starter-alternator design.

Advantages include low cost, low complexity, and no interior cabin sacrifices in space.

Examples: Found on all hybrid vehicles as well as all current model BMWs, Porsches, Jaguars, Land Rovers, most Audis, Mercedes-Benz vehicles, and some GM vehicles.

Mild hybrid – up to 15% savings in fuel consumption

A mild hybrid vehicle that cannot drive on the electric motor alone (i.e. there is no pure electric vehicle mode). It uses a smaller electric motor and battery combination and therefore always needs the internal combustion engine working in tandem. The electric motor is there to assist the gasoline engine in propelling the vehicle.

The advantages are lower cost and smaller packaging than a full hybrid system.

Examples: Honda’s Integrated Motor Assist (IMA) in the CR-Z and Insight, General Motor’s eAssist system (e.g. on the Buick Regal)

Full hybrid – Up to 30% improvement in fuel economy

A hybrid vehicle with the ability to propel the vehicle solely on the electric motor alone without the assistance of the internal combustion engine.  However due to limited battery capacity a full hybrid is generally only able to do so under certain low load conditions such as light acceleration, light cruising, or in stop and go traffics at low speed.

The internal combustion engine will be summoned to step in to provide full acceleration as soon as those conditions are exceeded.

Advantages include significantly reduced fuel consumption, particularly in the city as the electric motor will do most of the work in stop-and-go traffic at low speeds.

Examples: Various Toyota and Lexus hybrid vehicles, Honda Accord Hybrid, BMW hybrid vehicles, Ford hybrid vehicles, some General Motors hybrids, Subaru Crosstrek Hybrid

Full plug-in hybrid – Up to 90% improvement in fuel economy (provided EV mode is mostly used)

Essentially a full hybrid vehicle with the ability to plug into a wall outlet or specialized high voltage quick charger to top up the on-board battery.

Plug-in hybrid vehicles tend to have bigger battery packs and higher output motors than their non plug-in versions. They are usually able to run the vehicle in Electric-only mode for much longer durations and even up to highway speeds.

These vehicles are designed to handle commuter-type range (20-100 kms) and conceivably can be driven in pure EV mode for extended periods without the internal combustion engine ever firing up at all as long as the battery pack isn’t drained and certain other conditions are met.

Examples: Toyota Prius plug-in hybrid, Ford C-MAX and Fusion Plug-in hybrids, Chevrolet Volt

Two Mode Hybrid

Essentially a full hybrid vehicle that can operate in two modes. Firstly like a regular full hybrid, and secondly as a variable system where the internal combustion engine and electric motors work in tandem and vary their power outputs depending on specific driving conditions.

Two mode hybrids were developed out of an engineering partnership among GM, Chrysler, BMW, and Mercedes-Benz.

Alternative technologies

Mazda’s i-ELOOP – Up to 10% improvement in fuel economy

Derived from “Intelligent Energy Loop”, i-ELOOP is Mazda’s in-house developed capacitor-based regenerative braking system. It aims to improve fuel economy in totally unobtrusive and less expensive ways.

The system converts kinetic energy and stores it in a capacitor to power all of the electrical systems in the vehicle. This system is less complex (and therefore smaller, lighter and less expensive) than a traditional hybrid and avoids the need for a  dedicated electric motor and battery.

Mazda also claims that the capacitors also have the ability to charge and discharge rapidly and are resistant to deterioration despite prolonged use.

i-ELOOP is expected to improve overall fuel economy by up to 10%, but like the hybrid systems is dependent on road conditions and driving habits.

This system is currently fitted to the 2014 Mazda6 and 2014 Mazda3.

Porsche Brake Energy Recouperation System

Porsche’s Brake Energy regeneration system incorporates a smart alternator that switches off when the car is accelerating or cruising to reduce the parasitic load on the engine.

The alternator only charges the battery when the car is decelerating, thus using its kinetic energy to provide power for the car’s on-board electrical system.

Visit an OpenRoad location near you to learn more.