Everyone can benefit from increased fuel efficiency, whether from the personal costs of gas prices or addressing carbon emissions, and the nations biggest push in its history aims to drastically change how much fuel our vehicles consume. A federal mandate requiring 54.5 MPG on all cars released by 2025 puts the fire under automakers to increase fuel economy. The answers come from ideas as simple as aerodynamics and weight, but range to the complexity of variable timing valves and more. Lets explore some of the practical science being used here.

Aerodynamics and weight is a great place to start for increasing efficiency. we are developing technologies now give us lighter and stronger materials to make cars with. Advances in technologies with carbon fiber materials are close, and maybe the most simple efficiency measure to incorporate into cars. Lighter cars equals less energy to power them. The same goes for aerodynamics; less opposing force yields better gas milage. Automakers have tested many different shapes to make the body of cars to find the ones with the least drag coefficient, but also kept in mind that they want to keep these new ideas looking like the standard idea of a car. The simple outlook on aerodynamics is to keep the car body streamlined, but automakers have gotten a bit more creative than simply playing with shapes. Certain brands have tried out many options; replacing mirrors with cameras, using skinnier tires that have less drag, and perhaps the most creative, a grill on the front of a car that automatically closes when the engine doesn’t need cooling. The distant future of autonomous cars is certainly further away than 2025, but this idea with the grill and other features give an interesting look into what that may be like while working on efficiency.

The amount of gas wasted in city driving and in bumper-to-bumper traffic isn’t outrageously substantial, but there is plenty of energy there that companies could save, and that is exactly what has been done with the 2014 Chevy Malibu. Released last fall, it showcased an interesting feature that saves the wasted gas while idling a car. The engine automatically stopped when the car was brought to a stop. Consumers worried about the feel of the car when resuming acceleration, they worried it would be noticeable and annoying , but Chevy really performed on this one. The engine restarting is not even noticeable as it restarts automatically as soon as the driver begins to lift his/her foot off the brake. Truly innovative work by Chevy!
Variable valve timing is a more complex, mechanical aspect of working on fuel efficiency. The valves inside of an engine are used in combination with the pistons to make the crankshaft move and thus the car and important part of the valves and the pistons is mixing the right combination of oxygen and fuel to allow combustion. The way the valves opened in older cars, the engine often had to work harder to get oxygen, sometimes creating a vacuum, thus wear on the internal parts of the engine and a less optimal fuel-oxygen ratio. Today, with modifications among different brands, the valves are hooked up to sensors and when the valves yield less optimal ratios, an error message is sent to a computer, which adjust things accordingly.

The most effective method of conserving fuel, especially for highway driving, can be dealt with by not producing more power than is used. With V-8 engines and some V-6 engines, not all the pistons need to be used when traveling at a near-constant speed. When not needed (as determined by a computer) pistons can be deactivated by closing the valves which traps what would be the exhaust from the cycle and stops the piston in its tracks.

Most of these modern examples of fuel efficiency science are not very significant, and more advances will need to be made to reach 54.5 MPG by 2025. For now, these are the right steps to take as we wait for the science. Whether gasoline powered cars are on their way out or not, increasing fuel efficiency is a nice way to not only encourage that, but also to start to take action against emissions. And saving our wallets is a nice perk!

Sources: http://alternativefuels.about.com/od/researchdevelopment/a/cylinderdeact.htm
http://jalopnik.com/how-variable-valve-timing-works-500056093
http://www.freep.com/article/20130707/BUSINESS0101/307070119/general-motors-chevrolet-malibu-stop-start
http://motorburn.com/2014/01/12-of-the-most-aerodynamic-cars-in-production-right-now/