Seven Fuel-Saving Technologies That Are Changing the Auto Industry

Sami Haj-Assaad
by Sami Haj-Assaad

Every car, whether it has a big V8 engine or an electric motor powering the wheels, is being equipped with fuel saving technologies.

Recall variable-valve timing. Introduced on the Acura NSX, and at one time a revolutionary technology, now practically all cars have some form of VVT. Now more technologies are being introduced as innovations for saving fuel. Let’s take a look at some of the more important and popular features being introduced on new models; many of which will soon be as prevalent as variable valve timing.

1. Start-Stop systems:

You might think that an idling car isn’t too big of a deal, especially when it’s just for a stop-light, but all those seconds add up. After making a big splash with hybrid vehicles, idle start-stop systems are starting to show up everywhere.

There are a few different kinds of start-stop systems, and for different kinds of vehicles. In mild hybrids, start-stop systems consist of a gas engine, an electric starter/generator and a beefy battery. When the car is braking, regenerative brakes store the energy from the deceleration of the car in the battery. When the car is stopped, the generator shuts off the gas engine. When you need to get moving again, the car uses the energy stored in the battery from the regenerative brakes to work the electric starter and start the engine. Items like your car radio still work thanks to the stronger battery used in this system. If the stop is prolonged, however, the gasoline engine may come on.

In some vehicles, there isn’t a need for all that complicated technology. Rather than requiring heavy and expensive electrical components Mazda uses a start-stop technology called i-stop that puts a piston in the best position to restart the fastest when the engine turns off. That piston would already have air and fuel ready to be ignited, so that when the car needs to start again, it doesn’t require much time or power. This allows the car to start in as quick as 0.35 of a second. Other car companies like Mercedes-Benz are using technology like this in its big cars too. Mazda states that its start-stop system results in about 10% better fuel economy and while no Mazda vehicle is available with the feature in North America, look for it to arrive soon.

Currently government fuel economy testing methods don’t take into account start-stop systems, so for cars that do come equipped with them, like the 2012 Kia Rio, real world fuel economy numbers could be better than advertised. If and when government testing does take into account the benefits of start-stop systems, look for this new feature to go mainstream.

2. Variable Displacement/Active Cylinder Deactivation:

SLK 55 AMG (R 172) 2011

Another way to help improve fuel economy is to shut off unnecessary cylinders. Mercedes-Benz uses a cylinder deactivation system that deactivates half the cylinders in its V8 and V12 engines, essentially turning them into more frugal 4, or 6 cylinder engines. GM has a system that’s present in quite a few of its trucks that shuts off half the cylinders in the engine when cruising. This is also present in sportier cars like the automatic transmission equipped Chevrolet Camaro SS.

Chrysler’s version of cylinder deactivation is present on its HEMI V8s. In Chrysler products the system will shut off half the cylinders at speeds above 18 mph during moderate rpm. Chrysler says that thanks to cylinder deactivation technology its vehicles have 10-20% better fuel economy.

Honda also offers a cylinder deactivation technology called variable cylinder management (VCM) that shuts off two or three cylinders in V6 models like the Accord, Pilot and Odyssey.

3. Direct Injection:

Fuel efficiency might mean frugalness to some people, but it also means getting the most out of your engine. Direct-Injection means that the gasoline is injected right into the cylinder chamber of each cylinder in the engine, and at such a high pressure that the liquid gas is actually a gaseous gas, mixing better with the air and improving combustion. This improved combustion means more power is being generated, and as a result fewer emissions remain.

James hope, Kia Product Communications Manager explained that due to direct-injection, along with other key technologies, the Kia Optima is able to achieve best-in-class highway fuel consumption with its 2.4-liter 4-cylinder model, and tons of power from its relatively small 2.0-liter turbo.

4. Smart Alternator:

Hyundai has been boasting its smart alternator technology, which is in all of its U.S. Models. The major function of this alternator is that it chooses the best time to recharge the car’s battery. For example, when you’re decelerating, the system will kick in to charge the battery, as opposed to when you’re accelerating, and likely want all of the cars available power. “It allows us to cut the alternator drag,” said Derek Joyce from Hyundai Public Relations. “It basically recoups energy that would probably be wasted anyways.” Joyce also said that the technology helps improve fuel economy by around 1.5 to 2 per cent.

5. Electric Power Steering:

Furthermore, many companies are switching to electric power steering instead of conventional hydraulic steering systems. Rather than powering a hydraulic pump and keeping up system pressure at all times, the electric system only needs to engage when steering is required. Not only does the system save fuel by not being a drag on the engine at all times, it also helps cut weight by removing all the hydraulic components. The new Chevrolet Malibu Eco features this electric power steering and Chevy says it can help improve fuel economy by up to 2.5%.

Mark Meyers, General Motors global vehicle performance manager said “Electric power assist steering is just one example of how a system improvement can deliver not one but several benefits for customers.” He added that “By the end of the 2013 model year, more than half of all Chevrolet, Cadillac, Buick and GMC vehicles will have electric power steering.” Electric power steering is also making its way into BMW models, as well, as part of its EfficientDynamics philosophy and can be found on everything from Ford and Dodges to Hondas and Hyundais.

6. Eco Button:

Your next car may also feature a little button somewhere on the dash that helps get your more miles per gallon. “When activated, ECON mode alters the Drive-by-Wire throttle system response curve in the range from about 10 percent of pedal movement to 80 percent,” said Chris Martin, from Honda Public relations, about what the ECON mode button does in the new 2012 Honda CR-V.

He added that “With less gain, the throttle opening in this range increases more gradually to reduce a potentially excessive peak input for better fuel efficiency.” He explained that ECON Mode affects more than just your throttle though. “ECON mode also alters the operation of the cruise control system and the air conditioning system, allowing for slightly increased variances with the set speed or the set temperature in order to conserve fuel whenever possible.”

Many other automakers, from Chevrolet to Hyundai use an “eco mode” that puts the transmission on a short leash, making the vehicle shift sooner into higher gears when accelerating to reduce engine rpm and save gas.

7. Low Rolling Resistance Tires:

Finally, more and more companies are including low rolling resistance tires on their vehicles. Martin says “[Honda] has had great success working with the tire manufacturers to develop all-season tires that provide handling expected and appropriate for each vehicle while significantly reducing rolling resistance.”

Low rolling resistance tires minimize energy wasted from friction between the tire and the road. Traditionally used only on hybrids, these tires are now being used on a wide variety of models. Mazda recently started including low rolling resistance tires on its Skyactiv Mazda3. These can result in pretty significant fuel savings, up to five per cent. However, there are certain compromises when having low rolling resistance tires. They tend to not be as grippy as traditional tires, and can even be less comfortable.

With automakers still wanting to offer a wide range of vehicles by combining several of these seven new fuel-saving technologies it’s possible to make a noticeable improvement in fuel economy, without having to make due with a smaller engine or switch to a hybrid powerplant.

Sami Haj-Assaad
Sami Haj-Assaad

Sami has an unquenchable thirst for car knowledge and has been at AutoGuide for the past six years. He has a degree in journalism and media studies from the University of Guelph-Humber in Toronto and has won multiple journalism awards from the Automotive Journalist Association of Canada. Sami is also on the jury for the World Car Awards.

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2 of 5 comments
  • Ladylion Ladylion on May 28, 2012

    How come Ford is not mentioned.......a good article would be montioning all manufacturers, not just select ones.....for example.... By the end of the 2013 model year, more than half of all Chevrolet, Cadillac, Buick and GMC vehicles will have electric power steering. Ford already has this in all their vehicles

  • Durga prasad Durga prasad on Oct 20, 2012

    is power brakes work when a running engine is off