Since the Arab Oil Embargo of the mid-1970s, automakers and government officials have been on a quest to boost fuel efficiency. The gains have come slowly, but today’s average unadjusted fuel economy for passenger cars sold is 29.8 mpg, up from a Corporate Average Fuel Economy target of 18.0 mpg in 1978.
Up to now, the improvements have mostly been a direct result of smaller engines. But there’s more to come. Next-generation autos will benefit from the use of lightweight body panels, less wiring, and a host of up-and-coming engine technologies, including direct injection, variable valve timing, and cylinder deactivation.
We’ve collected photos of some of the most promising technologies. From turbochargers and electric motors, to motor-generators and air conditioning compressors, we present some of the best fuel-sipping innovations.
Click on the VW XL1 to start the slideshow.
Theoretically, the plug-in hybrid can achieve extraordinary fuel-efficiency numbers, given the proper driving schedule. Volkswagen’s proposed XL1 is one such vehicle, reaching 261 mpg, the automaker says. To accomplish that, the XL1 employs just about every imaginable fuel-efficiency technology, including a 47-HP turbo-diesel engine, a 27-HP electric motor, carbon fiber-reinforced plastics in its monocoque, body panels, and anti-roll bars. The brakes also use carbon fiber ceramics, while the engine crankcase, steering gear housing, dampers, and other suspension components are made from aluminum. Even the XL1’s windows were designed with weight reduction in mind, all of them being made from polycarbonate. (Source: Volkswagen)
Aluminum wiring is a very bad idea. It oxidizes and corrodes very easily, causing unreliable operation and possibly a fire hazard. They tried that with house wiring many years ago with very bad results. If aluminum wiring is used, then the connectors must be welded, not crimped to the wire. The automotive environment is far worse than the household environment.
There is a serious error in jts's post. Almost no modern automobiles use the carburetor,. This is specifically because it is difficult for a carburetor to maintain optimum fuel-air stoichiometry under the widely varying load and speed conditions encountered by a car engine. Modern autos therefore use computer-controlled fuel injection which constantly optimizes the mixture using feedback from exhaust gas composition and operating conditions.
I am surprised that the myth of the "miracle carburetor" still persists. Were it possible to achieve a significant efficiency gain merely by changing the carburetor, the auto industry would have done so many decades ago, rather than endure the cost of converting to the feedback-controlled injection system.
Carburetors remain satisfactory in engines with a relatively narrow range of speed and load, such as boats, airplanes, and many stationary applications.
I would strongly suggest that tjs, review a college textbook that covers the thermodynamics of the Otto cycle.
The 'cylinder deactivation' is a pretty ingenious solution at increasing a vehicle MPG rating. It's even more surprising that it comes from GM, perhaps it will be something that's 'recalled' in the future.
Path, I have already optimized one of my routes to minimize our stop signs, which the city management loves stop signs, 4-way stops even more. Adding a few turns that require letting off of the gas is not so bad, avoiding about 8 stops in two miles is good. Adding a heavy tax on things that impede traffic flow, incresing both fuel consumption and pollution that results, might be a good idea. They may even be able to balance the budget with all thqat extra income.
The hills thing is an interesting concept, probably congress would vote it into law if it were presented. BUT some cities are so flat that it would not be possible. How many hills are there in Phoenix, Az?
This idea is quite fascinating. It will eventually increase the mileage that drivers cover with there vehicles. This idea will boost the economy and encourage more people to get there hands on vehicles. This has made the work of tax payers easier and efficient. It is amazing that the vehicles will be much lighter since they will have lighter body weight parts, there will be less wiring on the vehicles and the engine technology will be much more boosted. I am definitely looking forward to these innovations.
The question of whether engineers could have foreseen the shortcut maintenance procedures that led to the crash of American Airlines Flight 191 in 1979 will probably linger for as long as there is an engineering profession.
More than 35 years later, the post-mortem on one of the country’s worst engineering disasters appears to be simple. A contractor asked for a change in an original design. The change was approved by engineers, later resulting in a mammoth structural collapse that killed 114 people and injured 216 more.
If you’re an embedded systems engineer whose analog capabilities are getting a little bit rusty, then you’ll want to take note of an upcoming Design News Continuing Education Center class, “Analog Design for the Digital World,” running Monday, Nov. 17 through Friday, Nov. 21.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.