Four-cylinder engine and many others like it can improve, to slow global warming.
Image: Oleksiy Maksymenko Alamy
In Brief
- Hardware and software changes to the internal-combustion engine in cars can make it much more fuel-efficient.
- New rules due soon from the Environmental Protection Agency governing greenhouse gas emissions and from the Department of Transportation on fuel economy will force the efficiency of cars, SUVs and pickups to rise 4.4 percent a year from 2012 through 2016 and probably more in later years.
- Technologies such as direct gasoline injection, variable valve timing and cylinder deactivation can reduce the major sources of energy loss in engines: waste heat and engine friction.
Demand for automobiles is rising worldwide. So is concern about greenhouse gas emissions. In response, scientists and engineers are working diligently to perfect new power plants for future vehicles, including battery and hydrogen fuel-cell electric cars. Although these and other alternatives show great promise for the long term, perhaps the single greatest way to reduce fossil-fuel consumption in the near term is to further improve today’s dominant transportation power plant: the gasoline internal-combustion (IC) engine.
Fortunately, efficiency can be raised in a number of ways, notably, better control over the air-fuel mixture entering the combustion chamber, over the way gasoline is ignited there, and over the mechanical systems that harness that energy. These can improve traditional automobiles as well as gasoline-electric hybrid models.
This article was originally published with the title Better Mileage Now.
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49 Comments
Add CommentWhy is the FOUR-CYLINDER ENGINE shown on it's side or am i missing some point?
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Reply | Report Abuse | Link to thisThe best way to make cars more eff is build them in composites at 1/2 the weight and aerodynamic with 1/3-1/4 the engine.
An ICE's problem isn't it's eff but the fact it has much more power than needed. It needs to run eff be run at near full power. If not say cruising at 60 mph the 200hp engine is only using 10 hp but also another 10 hp in internal engine friction. Just the power idling would move a good EV at 60+mph!!
This is called part throttle eff. Until ICE's can solve that they will be grossly inferior to EV's. EV's are not just the future, many of us have them now though most of us had to build from scratch or convert a car to get one.
The best way to do an ICE is a small 10-20hp motor running at it's most eff point charging batteries if necessary, of an EV. But as fast charging/ battery swap stations and EV's hit the road, even that use for an iCE would go away.
Nice catch on the sideways engine pic !!!
I have been reading Scientific American since the 1960s and I will simply say that it isnt edited like it used to be. The motor rotated 90 degrees makes me a little sad.
Reply | Report Abuse | Link to thisI seriously doubt that fuel efficiency will rise 4.4% per year for the next 5 years, and more in later years. This problem will be attacked by the U.S. automakers the same way as it has been attacked in the past. There will be small improvments to fuel economy for most of the fleet. However, trucks and SUV's will continue to be their bread and butter products. To compensate, they will make more small cars than the market demands, forcing them to cut the price and ultimately the quality and features of the small cars. They will be helped out by their "partners" in the government with subsidies and tax credits to push the small cars and raise the overall mpg of the fleet. Also, since the feds are now tied financially to the automaker's success, expect quite a bit of fudging of the rules and calculations.
Reply | Report Abuse | Link to thisI know how to get people to design, build & buy cleaner cars. And it's cheap! $12 per car. Run a length of hose from the muffler to the interior of the cars cabin. That's it!
Reply | Report Abuse | Link to thisI'm fairly certain people will gravitate to the cleaner, more efficient cars quickly, and those that don't, well, they'll remove themselves from the data set quickly enough.
not ever going to press the subscribe or purchase button, I guess my days of reading sciam on the internet are closing.
Reply | Report Abuse | Link to thisThere's so much still that can be done on the engines to make them more efficient, on top of weight reduction and better aerodynamics for the cars themselves. A turbo, for instance, can reduce an engine size dramatically and give the same power output, and turbos are very efficient as they use waste-power (exhaust) which would otherwise go unusued out the tailpipe.
Reply | Report Abuse | Link to thisHonda has been leading designs in cam variablitiy ever since inventing Vtec (which came from designs on motorcycles), now with iVtec and other cam manipulating technologies, the engines run with optimum valve timing fuel injection etc. Small cars are also becoming "cool" to drive, not to mention affordable. If every Sunfire p.o.s. becomes a smart car, and every Suburban becomes a Sante Fe, emissions will be vastly reduced.
Truck drivers account for a lot of the ICE pollution though, in their big rigs. Perhaps we can develop more rail systems to get some big dirty trucks off the roads.
Also, sea shipping can become way more efficient... there was an SA article about some super efficient, super-tanker in Copenhagen which is great. I'm liking the trends!
Recently many people have started to build external combustion engines which are far more efficient than internal combustion ones. Look up 'Stirling engines', which use heat produced from carburants with great efficiency. The days of the external combustion energy are numbered as future technology will favour energy efficiency over maximum performance...
Reply | Report Abuse | Link to this"The ICE probelm isn't eff, but that it has much more power than needed." You hit the nail on the head! I owned a Toy SR5 pickup with a 2.0 L engine in the 80's that got great economy. Who makes a 2.0 L pickup today?? We can improve fuel econonmy by 10% tomorrow, never mind 4.4%. We may WANT more power, but what do we need?
Reply | Report Abuse | Link to thisjerryd – Good summary of practical combustion efficiency issues, but it seems Texans like run their 400 bhp Hemis all the way up to 80 mph! The technological breakthrough needed is to run 426 Hemi sonics on those EV big bass boomers!
Reply | Report Abuse | Link to thisBehold, the environmental mentality. Summed up in two words:
Reply | Report Abuse | Link to thisYou can't.
Lighter cars don't have to be less safe, in fact can be more safe with little steel at all. Composites are far stronger than steel and foam far more safer in a crash for absorbing energy.
Reply | Report Abuse | Link to thisUsing composites, EV drive, 40-60 mile battery pack and a 20kw gas generator even large SUV's can be 50 mpg after the battery range.
Soccordad the troll. Do you ever have anything but negative, bad info to say? It must be miserable being you.
I've never figured out why people need more than 100hp for any vehicle. Semi's use to have just that!! If they can deal with 100hp and 40 tons, can't we in a car?
Eco-Steve stirlings have never and never will be as eff as ICE's. Possibly steam in uni-flow engines running gens to charge EV drive batteries might. Another is using steam run from Semi's exhaust, say 100hp ICE, 40hp steam waste heat motor with 200hp EV drive could be very eff for semi's. preferably run on NG could get with truck/trailer lightening, aero 12-15mpg.
I can see many small cars using a 600CC turbo, direct injected 100hp motors with start/stop as a future ICE.
A big thing though I think will be 600-1000lb 3wheel EV commuters with 80mph and 100 mile range selling for just $8-10k getting 3-400mpg equivalent.
Why all this will happen is next yr gas will be $5/gal and up $1/gal every yr afterward until it gets about $10/gal when alt fuel, EV's will be enough to stop it's rise, replace it.
jerryd – Good points again, but seriously:
Reply | Report Abuse | Link to thisLarge truck diesel engines generate very high torque (take-off power & acceleration). High horsepower is needed to increase speed.
Your visions of the future seem to be based on ideal product design and technology, which is understandable. However, actual high volume product designs are based on such mundane considerations such as manufacturing facility investments, component cost and reliability and market acceptance. If a startup could raise unlimited venture capital and generate sufficient market excitement, your product vision could take off.
Back in the 1970s, us forward thinkers all thought that if gas prices ever reached n dollars ($1/gal? – I only remember 25 cents/gal in the late 1960s), we’d all be driving hydrogen burning ICEs. Gas prices in Europe are probably already over $5 (sorry, I'm not doing the research to make this small point).
Good intentions, though! Who really knows?
Hi Jerryd: As you say stirling engines are not direct drive motors for vehicles. But they are great at powering electrical generators, which in turn drive the wheels and store excess energy in batteries......This is why they can be adapted to convert wasted chimney heat into electricity to improve their energy efficiency. There are an enormous number of situations where they can convert wasted heat. The commercialisation is only now just really beginning, because in the past energy was sold too cheaply, giving little incentive to use it to its full potential.
Reply | Report Abuse | Link to thisAthough I would agree that a turbo is more efficient at some speeds and especially in a diesel engine, the exhaust heat is not all that drives it. Turbos have significant backpressure on the exhaust system. They are driven by the engine (drag). The efficiency comes from extracting more energy from the fuel, but it is not entirely free.
Reply | Report Abuse | Link to thisI know everyone wants to do the right thing for the planet, how- ever the reality is that there needs to be more help from the petrolium companies, EPA and the Government to make the change for a better and cleaner planet.
Reply | Report Abuse | Link to thisI like realism as opposed to dreams that will likely never come true. CAFE standards have been the most damaging policy ever for the American automobile industry. Expect more of the same going forward with the new unrealistic standards.
Reply | Report Abuse | Link to thisMost people want a practical car that they like to drive at a reasonable cost. The market for tiny ultralight cars with expensive drive trains in the name of squeezing out a few extra mpg is not that large.
Someone mentioned that gasoline prices are higher in Europe. Consider this: Currently the price at my near pump is 1.34. And that is euros per liter. Multiplying to get gallons and dollars, the price is 7.14 USD / gallon. When your price is like that, then you (hopefully) understand why people in Europe don't want to drive those gasoline hogs you used to like. If it is relevant to someone, I live in Finland.
Reply | Report Abuse | Link to thisJokunen – Thanks for the converted European fuel costs. U.S. fuel taxes still haven’t caught up with Europe’s. No matter what the price is, we always feel that if it goes one more nickel we’re going to quit using the stuff, but it never seems to works out.
Reply | Report Abuse | Link to thisBy the way, Jokunen, did you ever spend 12 hours driving from Houston to Kansas City? Those long straight highways get pretty tough. Europe’s still got better handling cars, too, but ours have been steadily improving. Good luck with your taxes.
The way to go in the US is increase gas taxes, as in Europe, instead of imposing design changes on manufacturers. Instead of taxing motorists indirectly, through higher car prices, without giving them any choice, you tax directly, and preserve the choice. You do not see many gas guzzlerz in Europe, but if you can afford one, at $7 per gallon, go ahead, you won't have much company. Additionally, instead of talking of this red herring, the global warming, we need all the fuel efficiency and alternatives we can get to get off imported oil. This is so obvious, for so many reasons, and yet, as a rationale for promoting economy, it is presented as a distant second to the purely political global warming.
Reply | Report Abuse | Link to thisStirling engines, and any kind of external combustion engine, are perfect from an emissions point of view, but the thermodynamic cycle they use is inherently less efficient than internal combustion engines, as turbines, they have a delay in responding to driver's sudden demands, and use more fuel. Even though, somebody was able to fly an airplane fitted with an steam engine. Diesels use less fuel because high compression ratios increase efficiency of engine, they last longer too, but breakdowns are more expensive to repair, they are heavier and have a lower rpm limit than gasoline engines, thus limiting top power. What about sleeve-valve (Burt-McCollum) and modern Wankel rotary engines?
Reply | Report Abuse | Link to thisJust to reinforce Jokunen's point, the price of petrol in the UK (a country that produces some of the oil it consumes) is slightly upwards of 8 USD/american gallon when converted.
Reply | Report Abuse | Link to thisAs a very natural consequence, the size of the average car on british roads is significantly smaller than the average on american ones, and so are their engines. Most city residents use small hatchbacks, while hybrid vehicles are quite common and rapidly gaining in popularity. In larger cities with better commuting infrastructure, many people are only using public transport and keep their cars for the occasional trip to the countryside. SUV's are quite a rare sight and muscle cars are almost unheard of.
So, if you rapidly want to increase your fuel efficiency, it is very easy to do, all it takes is a change in your consumer habbits. The vast majority of people in the US only need to travel a few kilometres per day to get to their work and back, and for these distances, anything bigger than a hatchback is an overkill.
Green roads for electric cars.
Reply | Report Abuse | Link to thisTo a herbivore grass is nothing but a energy resource to keep the engine going spread over a large area. So I wonder how much the total road area is and the energy that it is exposed to by the sunlight every day. What technical solutions do we have to harvest and distribute this resource? If possible then it would mean at the very least you could extend the range of electric cars by transferring solar energy gathered by the roads.
To a herbivore grass is nothing but a energy resource to keep the engine going spread over a large area. So I wonder how much the total road area is and the energy that it is exposed to by the sunlight every day. What technical solutions do we have to harvest and distribute this resource? If possible then it would mean at the very least you could extend the range of electric cars by transferring solar energy gathered by the roads.
Reply | Report Abuse | Link to thisWhy did you show a picture rotated 90 degrees?? If you don't know what you are looking at, do you know what you are talking about??
Reply | Report Abuse | Link to thisI had an '89 VW Quantum Turbo Diesel (same thing as an Audi 4000) that got 50 MPG all day, every day, for more than 200,000 miles. Plenty of pep, great handling, extremely reliable, power windows, big enough. I still have the fuel records, every tank full with mileage and date.
I'd still be driving and enjoying it but I accidently destroyed it.
jtdywer wrote
Reply | Report Abuse | Link to thisjerryd – Good points again, but seriously:
Large truck diesel engines generate very high torque (take-off power & acceleration). High horsepower is needed to increase speed.
JD If you look at my semi power system you'll note a 200hp EV drive which alone puts out far more torque than a 600hp diesel does. Now add the 100hp NG and 40Hp steam waste heat engine and it out classes even 800hp diesels in power at 1/3 the fuel use.
Your visions of the future seem to be based on ideal product design and technology, which is understandable. However, actual high volume product designs are based on such mundane considerations such as manufacturing facility investments, component cost and reliability and market acceptance. If a startup could raise unlimited venture capital and generate sufficient market excitement, your product vision could take off.
JD Well if you look at the increase in MC's, NEV's and the large drop in vehicle sizes over the last 2 yrs this has already started. My vehicles are just a cabin, safer version of MC's, mostly 3wh EV ones. I drive them now at 1/4 the cost of a similar ICE.
You'll find composite construction is far cheaper to start, run than overweight steel just a 1k/yr production line is very profitable. As my health gets better I'll be doing just that as will many of the X-Prize 100mpg contestants will.
Why is next yr gas will be $5/gal as the economy recovers and up $1/yr after that.
Do you like unusual engines? Taste this: enter www.oepm.es go to the Invenciones en espanol database, interpat, and look for the following patent numbers: P0546679 (rotary engine), P0272123 (square arranged pistons), P0156621 (double expansion engine, supposed to have low SFC), and P0433850 (5 stroke engine, also supposed to be economical). When dealing with marvelous engines, please note that there is almost nothing new under the sun, you can have lots of fun by looking into patent databases. Salud +
Reply | Report Abuse | Link to thisEach one of us could save ~10% in fuel costs just by modifying our driving habits! [search the internet for 'hypermiler techniques' for examples] A simple fuel consumption device can be purchased for around $200 for cars that don't already have one. It can pay for itself in a few months for most!
Reply | Report Abuse | Link to thisHow widely is is appreciated that Diesel and Petrol engines have opposite characteristics wrt fuel efficiency ?
Reply | Report Abuse | Link to thisA diesel gains from its relatively huge expansion ratio only when supplying a fraction of its maximum torque, this is why big diesels are fuel efficient compared to petrol engines - if driven lightly !!
A petrol engine wastes power at low throttle settings through the work done dragging the pistons down against the low manifold pressure on the induction stroke.
To get best efficiency from a petrol car, therefore use the higher gear and larger throttle - and don't hurry in either case
(diesel or petrol) No ammount of "fuel injection" fantasies etc. can ever change this.
Incorrect use of adverb "vastly". Emmissions will be "vastly reduced" when drivers become aware of what they are doing and
Reply | Report Abuse | Link to thisa) Drive diesel lightly and in the lower rather than the higher gear
b) Drive Petrols in the higher, rather than lower, gear with larger rather than miserly, throttle. Miserly throttle on petrol causes drag from the below atmospheric pressure in the inlet manifold.
Unfortunately, the story that lighter cars are less safe is a myth propagated by Detroit, the home of the SUV and the truck.
Reply | Report Abuse | Link to thisSmall cars like the Smart pass all safety regulations with ease and are probably safer than a shoddy SUV. Just because Detroit doesn't want to make safe small cars doesn't mean it can't be done.
Anything can be "pattented". All you need is the fee !
Reply | Report Abuse | Link to thisLet us do the following:1-direct multi point injection of fuel mixture fifty fifty diesel and gasoline in a micro processor based fuel compression /injection unit . 2- use of exhaust heat in air condition in cold countries and driving turbocharger for producing electricity in battery charger for for home electricity taking connection from garrage. Use solar energy on car top panel for car slow speed propagation on long highway in pleasure drive instead of gasoline as fuel. So modern cars should of modern design for long term cost benefit.
Reply | Report Abuse | Link to thisWhatever it is that you have in mind, certainly no glimmer of an idea - let alone a good one !- comes through from your comment
Reply | Report Abuse | Link to thisPlease ! - Go away - sit down - and sort-out your head , then maybe try again ?
Yes 30kW steam plant - particularly open cycle - is very light and cheap, as is the tender of water to lug-along. Why not put a gearbox after the "EV drive" when unlimited torque could become available. Just an idea - keep smilin !
Reply | Report Abuse | Link to thisStirling cycle can be more efficient than Otto, Diesel and Wankel cycles from a theoretical point of view, but probably, this cycle is not obtainable in practice, what can be implemented is a blunted practical version of Stirling cycle that is not so efficient
Reply | Report Abuse | Link to thisOtto, Diesel, and Wankel, are not "cycles", they are the names of :
Reply | Report Abuse | Link to thisa) The inventor of the 4-stroke internal combustion engine
b) The inventor - and creator - of the a piston engine where the fuel is injected into the space above the piston, at the top of the compression stroke (and some little way thereafter). The compreesion ratio needing to be high enough, to make the gas hot enough, to cause the fuel to ignite as it enters the small space. Thermodynamically it is similar to the Steam locomotive, i.e. pretty much a "Constant pressure" cycle, because heat is added to the gas at approximately constant pressure.
c) Thermodynamically the Wankel engine is a piston engine the same as a petrol engine because the compressed mixture is ignited all at once, and heat is converted into work as the volume increases as the mechanics move, which cools the gases . They are both examples of the "constant Volume" cycle because heat is added to a constant Volume of gas.
The Sterling engine has the dubiuos honour of a completely undefineable thermodynamic "cycle", but is of course subject to the pure mathematics of Msr. Carnot, who was first to show us that the maximum possible fraction of the heat from a fuel, that can be converted into useful mechanical work, is determined entirely by the (temperature of gasees to start with (at ignition) -minus the exhaust temperature) all divided by the highest temperature. i.e.
Max poss efficiency = (Th - Tc) / Th or 1 - Tc/Th all temps. in degr. K
This tends to severely limit the Stering engine's thermodynamic efficiency, but it may find a niche where there are huge Quantities of "low-grade heat"
i.e. Th not produced from FIRE - but where ?
I get the feeling that it will never compete with a well designed "Gas turbine"
Engine on it's side fit the page better....wouldn't run long in that position though. Most people reading this artical probably don't know the difference, hence the side-ways oil pan.
Reply | Report Abuse | Link to thisI suppose if one were traveling in a car going around the old Parabolica a Monza it would be possible for this engine to live, but only if you were doing it continuously.
How come the new zero-shift technology was not mentioned? That would replace all automatic transmissions with a lighter and more efficient transmission?
Reply | Report Abuse | Link to thisWhy was the 'zero-shift' transmission not mentioned? That would be lighter and more economical than any automatic transmission?
Reply | Report Abuse | Link to thisStirling engines will not be chosen by people who want a maximum power curve. But if you care about preserving the planet's ressources, drive a stirling engine vehicle which will give you the best mileage and lowest NOx output. Economy is of course good for the pocket too...
Reply | Report Abuse | Link to thisthis whole article is a rehash of 100 yrs of ice tech. whats really needed is to stop designing fuel utilization at the same effeciency as over 100 yrs ago( appox. 24 %) there are thousands of patents & demo motors getting minimum 50% greater milage without redesining the engine.the problem is the corrupt union of oil cos & auto manafactures via the government.just look at paul pantones designs.THEY WORK. so does numerous other designs. bruce crowler has a 5 cycle engine where the 5th cycle injects wet steam into the cylinder atd center on the stroke. another 50% boost. cant get a car company interested.why ?? all these simple changes cut into the oil cos bottom line !the int cob eng can go for a very long time both more effecient & almost no pollution. build a pantone reactor & run your engine. see for yourselves. the public needen,t buy very high tech( very expensive) cars .some simple , honest inexpensive redesigns can work perfectly for both very large milage boosts & no pullution from the tailpipe.the government still doesn,t permit evaporative carbs. why?? take a guess. look up POGUE CARBS.they were only permitted during WW2.during the war fuel shortages. gone now thanks to HOLLY CARBS. all the junk additives in gas prevent evaporative carbs. try some camping lantern fuel in your tank. gasoline without the adds. bob reidel
Reply | Report Abuse | Link to this"the single greatest way to reduce fossil-fuel consumption in the near term is to further improve today’s dominant transportation power plant: the gasoline internal-combustion (IC) engine."
Reply | Report Abuse | Link to thisThe trouble is, more fuel efficiency means it's cheaper to drive. Economists tell us that making something cheaper results in people consuming more of it. And the increase accelerates. The demand curve is downward-sloping and convex:
http://en.wikipedia.org/wiki/Demand_curve
The increase in consumption to which you refer,
"Demand for automobiles is rising worldwide."
is due in part to the very mechanism you claim reduces fuel consumption. That is, improving gas mileage may very likely *increase* the aggregate demand for fuel, the opposite of the intention to dictate fuel economy.
first define the problem! fuel consumption isn,t the problem.the internal comb. eng. can run on water if properly set up!! the problem is government control of all aspects of our personal lives. exhaust generated steam run over a catalyst will generate hydrogen. cheap &pollution free. however a threat to the oil & gov bottom line( taxes !!!!) personal freedom & the market will correct any problems without the necessity of a HUGO CHAVEZ-CASTRO-BARAC OBAMA style dictation of what we should be doing. those who think we need the government to dictate ANYTHING are the real problem.PERSONAL FREEDOM solves all problems. PS i,m not for anarchy,just limited government . anyone who is interested email me & i will give you a method of setting up an engine to run cheap & pullution free. you will however need to use personal initiative & work to set it up. regards bobbyr
Reply | Report Abuse | Link to thisFuel Eff has always been a size/weight/speed ratio. Heavy cars in the US are favored/preferred due to 'safety' issues. Safety kinda means one won't get killed in a wreck. Speed kills, the saying goes, and driving from here to yonder takes forever at posted limits.
Reply | Report Abuse | Link to thisTime for a paradigm shift all the way around.
As to the $7.14/gal equivalent EU-US price, remember that EU prices include the VAT and a ton of other taxes out of which they subsidize things like... Health Care of all things. Thus every driver in the EU is paying for things that everyone that doesn't drive -PLUS- all the roads and bridges and retirement benefits. Such a mess... to an accountant. Keep up the good work!
Ok, so today we build IC engines using all the toys the racers thought up in the '60s and '70s. Roller cam, roller lifters, balance shafts and fuel injection. Some have gone on to produce more efficient transmissions. Add computer controlled ignition, shifting and variable valve timing (and drive) and you are in 2010 from 1960. Lightening the assembly with materials has not really produced much in the way of savings as the strength of materials marches to a different drummer. The basics however still rely upon bearings of many designs, all giving up something to friction. Add the wind, the temperature and the load carried - thus limiting fuel consumption. Better we learn to fly.
Reply | Report Abuse | Link to thisWhile I can't pretend to read the writers mind on the view of the engine, it occurs to me that it may have been turned that way to show the drive belts. Some of which would go bye bye with some of the suggested changes. That or the photographer just took creative license rather than worrying about what the motorheads out there would think of the engine being on it's side.
Reply | Report Abuse | Link to thisSmaller lighter cars are a good route to go. Amory Lovins who is on the board of american automotive engineers has convincingly shown that composite materials are scaleable for cheap production if there is a will to retool plants. A sixty percent lighter car could use a much smaller engine for identical performance The fuel savings would approach the weight reduction (IE fifty or sixty percent). Add to this some other up and coming technologies like opposed piston engines (Recently they've gotten around emissions issues with this engine type) and you have an even smaller engine and more efficient engine package with a lot of punch for it's size.
I don't see internal combustion going anywhere for a long while yet, especially not with all the potential advances in efficiency. Amory Lovins makes a compelling case for simple efficieny measures and he does it by showing how profitable efficieny can be managing to make a tidy living off showing companies and heads of state how to make money out of being careful with energy use. Most of the measures he advocates go well beyond cars and many are easily implementable by the average home owner. Some estimates suggest we could cut fossil fuel use in this country by fifty percent without impacting productivity just bu adopting efficiency measures aggressively. This is also among the lowest cost options available to us. Not the solution to the whole problem but a very good bridging measure.
This issue is quite complicated and goes beyond the CAFE standards. It involves psychology and sociology as well as geography. The central core is where we can live. Not where we chose to live as with rising population, housing expenses, job availability not too many of us actually can select our place of residence.We need to be transported. In places too expensive already, like New York City, with available trains, people commute in trains. Boston has a similar situation but less rail available.Los Angelele, too little public and inconvenient transportation. So, we waste about 35% of our fuel speeding, driving with a high rate of anxiety, and without actually checking to see IF speeding actually helps. Well, I got news: it does not help. But will it stop this frenzy to know all you are doing is sending huge profits to the oil companies? Probably not. We are human and we use our emotions more than our intelligence. Too many drivers and passengers are still killed or seriously injured by not using seat belts. I can also get 40% less fuel efficiency by: refueling with the motor running; passing all others on the road; by looking for that specially close parking slot near the gym's door; by owning a car too huge for my needs (all for ego purposes or status); and by buying a car for each of my five children at age 16 plus one day so they can go to school not using the bus. Ego. Status.Emotions. Ignorance. All of these are the main causes of global warming. Good luck.
Reply | Report Abuse | Link to thisIf mileage starts at 20 mpg (say for a a light truck) and improves at 4.4% per year in 2012, it would reach about 25 mpg by 2016 and over 30 mpg by 2021. For cars that already get 30 mpg, mileage would improve to over 37 mpg in 5 years and 46 mpg in 10 years (it's exponential growth, which is sustainably only so long).
Reply | Report Abuse | Link to thisWow, by then the average US vehicle would be almost as efficient as Chinese vehicles are now.