12 fuel-saving technologies for a happy Earth Day

In honor of Earth Day, we take a quick spin around some of the technologies automakers use to save fuel in modern cars.

Emme Hall
I love two-seater, RWD convertibles and own a 2004 Mazdaspeed Miata for pavement fun and a lifted 2001 Miata for pre-running. I race air-cooled Volkswagens in desert races like the Mint 400 and the Baja 1000. I have won the Rebelle Rally, seven-day navigational challenge, twice and I am the only driver to compete in an EV, the Rivian R1T.
Emme Hall
1 of 12 Chevrolet

Electric cars

What started as a quirky car for hippies and other greenie types has evolved into an almost-practical car for everyone. Many electric vehicles like the Honda Fit EV, Fiat 500e and the Nissan Leaf are pushing 90 miles of range on a full charge, although they're dwarfed by Tesla and the Chevrolet Bolt, rocking out over 200 miles of range. Single drivers can use the carpool lane, charging stations are getting to be more common and you get all that sweet, sweet instant electric torque off the line.

Porsche 918 Spyder
2 of 12 Porsche

Plug-in hybrids

Plug-in hybrids use a gasoline engine and a rechargeable electric motor, either using the engine to recharge the battery or using a combination of battery and engine. Hybrids can travel anywhere from 15 to 50 miles on electric power alone, and can get over 300 miles of range in gasoline/battery mode. Probably the best-known hybrid is the Toyota Prius, but we thought we'd give you a photo of the Porsche 918 Spyder. Yep...it's a hybrid.

Toyota fuel cell stack
3 of 12 Toyota

Fuel cell vehicles

Did you know hydrogen fuel cell cars are available, right now? True, they're only available to us fruits and nuts living in California, but that was once true of electric cars as well. Cars such as the Toyota Mirai, Hyundai Tuscon and upcoming Honda Clarity run by mixing hydrogen and air to produce electricity and water. According to the US Department of Energy, there are currently 24 public hydrogen fueling stations, where it can take as little as 3 minutes to fill the tank. Toyota claims the Mirai can go 312 miles on a tank of hydrogen, while Hyundai claims 265 miles. Either way, let's hope the infrastructure expands quickly to help the sale of these dream machines.

Mustang active grille
4 of 12 Ford

Active grille shutters

Your traditional gasoline-powered car might already have this little bit of fuel-saving technology. Active grille shutters open when the engine needs cooling, but close when the engine is doing just fine, rerouting the air around the car to reduce drag, and thereby increasing fuel economy. Many manufacturers feature this technology, including Ford, Chevrolet, Mazda, BMW and Toyota.

Mazda's i-ELOOP system
5 of 12 Mazda

Kinetic energy recovery

Both Mazda and BMW use technology to capture kinetic energy lost during braking, converting it to electricity to power accessories. Instead of using fuel to run creature comforts, anything from the stereo system to the headlights to climate control can be powered by this stored kinetic energy. In addition to saving fuel, this method ensures there's no extra draw on the engine when something like the air conditioning is turned on.

Porsche Cayman Auto stop/start
6 of 12 Porsche

Auto stop/start

While it might be the bane of many an enthusiast, auto stop/start is an effective technology for reducing fuel consumption, especially in cities where "commuting" often means "sitting in traffic." Our own Brian Cooley found that fuel savings can be anywhere from 3 to 10 percent with auto start/stop. While the tech has been ubiquitous in Europe for quite some time, the US is quickly catching up, with Ford, Chevrolet and Ram all adding the technology across their lineups.

Cadillac CT6 engine
7 of 12 GM

Cylinder deactivation

Cylinder deactivation lets you have your big V-8 and drive it too. By shutting off fuel supply to half or more of the cylinders under light load, cars can get better fuel economy while cruising down the highway. It's been available for some time in cars from Honda, Mercedes-Benz and GM, as in the Cadillac CT-6 powertrain pictured here. GM, however, has been working with Delphi and Silicon Valley startup Tula Technologies to develop Dynamic Skip Fire. An algorithm (of course it's an algorithm) determines if each individual cylinder is needed to meed the driver's input. If not, shut it off, baby. This could potentially allow a V-8-powered vehicle to sail at highway speeds on two cylinders.

Continuously variable transmission
8 of 12 Nissan

Continuously variable transmissions

If you've looked at a new car lately, you've probably heard the acronym CVT. The continuously variable transmission does away with fixed gears in favor of a pulley system, which constantly adjusts the drive ratio to best match the optimum engine speed. And instead of the limited ratios, tied to the number of gears, in a conventional automatic transmission, the CVT offers, potentially, thousands of ratios. Letting the engine run at an optimum speed for as much driving time as possible leads to greater fuel efficiency. Currently Nissan, Toyota and Honda are big proponents of the CVT, but many enthusiasts find the transmission technology makes for a boring and droning drive.

9 of 12 Ford

10-speed automatic transmissions

You wouldn't expect the 2017 Ford Raptor race truck to have much in terms of green tech, but you'd be wrong. It navigates some of the world's toughest terrain with a 10-speed automatic transmission. Sure, we've had eight- and nine-speed autos for a while, but manufacturers are upping the ante again. More gears at the top make for low-rpm cruising, which in turn produces better fuel economy. Look for a 10-speed transmission to show up on all Ford F-150 trucks soon, as well as on the 2017 Chevrolet Camaro ZL1. GM has also said it will add a 10-speed transmission to eight models by 2018.

Bridgestone Ecopia tire
10 of 12 Bridgestone

Low rolling resistance tires

Low rolling resistance tires have become common on EVs and hybrids these days. They help cut down on the energy used to roll the tire down the road, thereby increasing fuel economy. How much of an improvement could you see? A 10 percent decrease in rolling resistance translates to a 1-2 percent improvement in fuel economy. It's not much but small goals can lead to a big win when taken together. If you don't have low rolling resistance tires on your car, be sure to keep them properly inflated. Look for the label on the doorjamb for the proper psi level and check pressures once a month when tires are cool. Under-inflated tires can lead to poor fuel economy no matter what kind of tires you have. Over-inflated tires can make for a rough ride and loss of traction, especially in wet conditions.

11 of 12 ZF Lenksysteme

Electric power steering

Back in the day, if your car had power steering it had hydraulic power steering. The system used pistons and pressurized fluid to boost your inputs to the steering wheel. What kept that pressure? A constant pump, powered by the car's engine. Now most cars have electric power steering, where a motor is used to help turn the wheels. This motor only takes power from the engine when needed, giving manufacturers gains of up to 4 percent.

2013 Honda Accord engine
12 of 12 Josh Miller/CNET

Direct injection

First there were carburetors, then fuel injectors and now we have direct injection engines. These engines add a squirt of fuel directly (get it?) into the combustion chamber, instead of into the intake manifold. As a result the computer has better control over the fuel-air mixture that goes boom inside the cylinder, ultimately making your car move. This leads to less waste, more power and better fuel economy. Bosch, a supplier of engine technology to many manufacturers, claims that direct injection can result in a 15 percent gain in fuel economy.

More Galleries

My Favorite Shots From the Galaxy S24 Ultra's Camera
A houseplant

My Favorite Shots From the Galaxy S24 Ultra's Camera

20 Photos
Honor's Magic V2 Foldable Is Lighter Than Samsung's Galaxy S24 Ultra

Honor's Magic V2 Foldable Is Lighter Than Samsung's Galaxy S24 Ultra

10 Photos
The Samsung Galaxy S24 and S24 Plus Looks Sweet in Aluminum
Samsung Galaxy S24

The Samsung Galaxy S24 and S24 Plus Looks Sweet in Aluminum

23 Photos
Samsung's Galaxy S24 Ultra Now Has a Titanium Design
The Galaxy S24 Ultra in multiple colors

Samsung's Galaxy S24 Ultra Now Has a Titanium Design

23 Photos
I Took 600+ Photos With the iPhone 15 Pro and Pro Max. Look at My Favorites

I Took 600+ Photos With the iPhone 15 Pro and Pro Max. Look at My Favorites

34 Photos
17 Hidden iOS 17 Features You Should Definitely Know About
Invitation for the Apple September iPhone 15 event

17 Hidden iOS 17 Features You Should Definitely Know About

18 Photos
AI or Not AI: Can You Spot the Real Photos?

AI or Not AI: Can You Spot the Real Photos?

17 Photos