Fuel efficiency of vehicles on the road: Little progress since the 1920s

May 05, 2009

(PhysOrg.com) -- Vehicles on America's roads today get only about three miles more per gallon than vehicles back in 1923, University of Michigan researchers say.

A new study in the journal by Michael Sivak and Omer Tsimhoni of the U-M Transportation Research Institute shows that overall fuel efficiency for vehicles in the United States was 14 miles per gallon in 1923 and 17.2 mpg in 2006.

The researchers documented and analyzed the annual changes in actual fuel efficiency of vehicles on U.S. roads from 1923 to 2006 by using information about distances driven and fuel consumed to calculate fuel efficiency of the overall fleet and of different classes of vehicles.

They found that overall fleet fuel efficiency actually decreased from 14 mpg in 1923 to a low of 11.9 mpg in 1973, but then rapidly increased to 16.9 mpg by 1991.

"After the 1973 oil embargo, achieved major improvements in the on-road of vehicles," said Sivak, research professor and head of UMTRI's Human Factors Division. "However, the slope of the improvement has decreased substantially since 1991."

From 1991 to 2006, fuel efficiency increased by less than 2 percent, compared with a 42 percent increase in mpg between 1973 and 1991.

According to the study, fuel efficiency for cars improved from 13.4 mpg in 1973 to 21.2 mpg in 1991, but reached only 22.4 mpg by 2006. For light trucks, the numbers were 9.7 mpg in 1966, 17 mpg in 1991 and 18 mpg in 2006. Medium and heavy trucks showed modest improvement from 5.6 mpg in 1966 to 5.9 mpg in 2006.

"Future improvements in fuel economy of vehicles are needed across the board, for both passenger and commercial vehicles," Sivak said. "Some of the improvements in effective fuel efficiency will come from the ongoing partial shift from using light trucks to cars for personal transportation.

"Given the differences in the fuel efficiency of light trucks and cars, a 25 percent shift would result in about a 2 percent reduction in the total consumption of fuel for all vehicles."

But the researchers say the focus should not necessarily be on classes of vehicles with the lowest , such as heavy trucks and buses, which have alternative societal measures that are relevant (e.g., miles per pound of freight or passenger miles per gallon).

Instead, the focus should be on the least-efficient vehicles within each class. For example, an improvement from 40 mpg to 41 mpg for a vehicle driven 12,000 miles per year saves 7 gallons of fuel a year. However, an improvement from 15 mpg to 16 mpg for a driven the same amount of miles saves 50 gallons of fuel a year.

"In other words, society has much more to gain from improving vehicles that get lower gas mileage," Sivak said. "Such improvements could be fostered by tax policies that assist the development and introduction of new relevant technologies and encourage scrapping older vehicles."

Provided by University of Michigan (news : web)

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User comments : 22

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DozerIAm
2.3 / 5 (4) May 05, 2009
fuel economy ON AVERAGE may not have improved, but nearly all the systems on cars have improved - engine efficiency, emission control, suspension, braking, and most importantly vehicle safety have all DRASTICALLY improved over that time frame. To ignore all the other aspects and focus on fuel economy in isolation is a bit silly.

...

and to then say Such improvements could be fostered by tax policies that assist the development and introduction of new relevant technologies and encourage scrapping older vehicles." is sillier still.
zevkirsh
2.3 / 5 (4) May 05, 2009
fuel efficiency on vehicles will improve dramatically when we stop using combustion. that will happen in 50 years.
joefarah
3.2 / 5 (6) May 05, 2009
Combustion engines will be hard to come by in 50 years. They will for certain, be the specialty, for applications not near a power grid. By 2020 most new cars will be electric, (unless H2 cars can cut through the safety and manufacturing cost issues).

High power applications will all be electric, as will low cost applications.

Also, the article says you save more on vehicles with lower mpgs by improving them. True, but there's not the same number out there, and the luxury vehicles will be the first vehicle class to go fully electric.

Want to save fuel - let's look at plastic or carbon-re-inforced bodies (no need to give up strength just because it's plastic). And go entirely electric. Hybrids carry too much weight and cost.
deatopmg
3.7 / 5 (6) May 05, 2009
AT WHAT SPEED!!! This is a gross distortion using partial information to fit some agenda.

the model T got about 25 - 30 mpg at 35 mph today's cars get about 70 mpg at 35 mph even though they weigh many times as much as a model T. These clowns appear to be stating mpg at the average speed of the day thus comparing apples and oranges - both roll but have completely different tastes.
John_balls
2 / 5 (5) May 05, 2009
fuel economy ON AVERAGE may not have improved, but nearly all the systems on cars have improved - engine efficiency, emission control, suspension, braking, and most importantly vehicle safety have all DRASTICALLY improved over that time frame. To ignore all the other aspects and focus on fuel economy in isolation is a bit silly.


He genius the whole purpose of the article was about fuel efficiency to talk about other parts of the system is irrelevant to the articles main point.



A point I'm sure you have a hard time grasping.



...





and to then say Such improvements could be fostered by tax policies that assist the development and introduction of new relevant technologies and encourage scrapping older vehicles." is sillier still.


Right, we now how the auto industy just tries to do the right thing. They have fought against almost every safety feature you enjoy today in your car.
John_balls
2.6 / 5 (5) May 05, 2009
AT WHAT SPEED!!! This is a gross distortion using partial information to fit some agenda.



the model T got about 25 - 30 mpg at 35 mph today's cars get about 70 mpg at 35 mph even though they weigh many times as much as a model T. These clowns appear to be stating mpg at the average speed of the day thus comparing apples and oranges - both roll but have completely different tastes.

AT WHAT SPEED!!! This is a gross distortion using partial information to fit some agenda.



the model T got about 25 - 30 mpg at 35 mph today's cars get about 70 mpg at 35 mph even though they weigh many times as much as a model T. These clowns appear to be stating mpg at the average speed of the day thus comparing apples and oranges - both roll but have completely different tastes.

Their is no agenda here my right winger.

Evidence just doesn't jibe with your DNA that you have been lied too.

Please show me a car that gets 75mpg while going 35mph that is not a hybrid.

Your probably not old enough or smart enough to know that their were plenty of cars sold in the eighties that got more mpg then most hybrids on the road today.
nkalanaga
3.8 / 5 (4) May 05, 2009
The 1994 Geo Metro got 62 mpg at 70 mph when new, and mine was still getting over 50 mpg in late 2006, when an idiot pulled out in front of me and wrecked it! True, it wasn't a fancy car, but it took two of us and luggage across the country five times in relative comfort, and was perfect for driving to work and back, 20 miles each way, daily. Never mind fancy new designs, I want a new 94 Metro!
MatthiasF
2.4 / 5 (5) May 05, 2009
Deatopmg,

There is relatively little difference in mpg impact from speed between 35 mph and 55 mph. Over 60 mph is a different story. So, no a modern car cannot get 70 mpg going 35 mph.

And no, they aren't comparing apples and oranges. They still have Ford Model T's around. To get the numbers you see, they run them through the same tests as modern cars to get the numbers you see. In some cases, the data comes from emissions tests by states (in order to allow the car on the road).

As far as the other posts, averages work well to spot trends in changes. While the engines might have become more efficient, the efficiencies are obviously hidden behind something incredibly inefficient. Perhaps a trend of customers buying huge, CAFE-standards-avoiding, sports utility vehicles?

http://en.wikiped..._Economy

And yes, older cars are less efficient, not because they were necessarily designed that much less efficient but from wear and tear or poor maintenance.
paulthebassguy
3.1 / 5 (8) May 05, 2009
This article only relates to "America's" roads. This only happens because american cars are useless, vulgar, and inefficient.
DoktorSerendipitous
4.2 / 5 (5) May 06, 2009
Not a surprising result, in view of the fact whatever the fuel efficiency improvements that automotive engineers had been able to achieve were squandered on additional amenities and convenience, which ended up adding more weight to automobiles. In addition, the introduction of freeways sacrificed fuel efficiency for the sake of faster travel time. Overall, however, I would suspect that a car traveling at 55 mph today is more fuel efficient than a car of the comparable weight 50 years ago--more so than the study suggests.

As for the possible alternatives to the internal combustion engine cars, an alternative existed at the very beginning of the era of automobiles--the electric car, but it failed. The reason for the failure is not that gasoline was cheap, but the grid-independent nature of the room temperature liquid fuel: one can stockpile the energy stored in liquid in a container, one can carry the container easily, and when the energy is expended, the container is empty--no heavy deadweight like the battery to carry around.

Hydrogen fuel is not the future of automobiles, although oil companies would wish it were, since much of the fuel supply grid that they created--gas stations--can be converted to handle hydrogen fuel, thus ensuring the survival of their business model--to keep consumers tethered to their energy supply grid. The reason hydrogen will fail is that it is far less grid-independent liquid fuel than gasoline: it can only be stored under the condition that can maintain high pressure; the container cannot be easily transported by the user, and the container is a heavy deadweight after the energy is spent. It has nearly all the portents associated with the failure of electricity as the "fuel" for automobiles in the early 20th century.

The situation for electricity has improved considerably in the meanwhile. In the early 20th century, there was no such thing as electrical grid outside of major cities, but now electricity is available in most part of the industrialized countries (not the case, however, in Third World countries), thus allowing electric cars to be recharged overnight at the owner's home. Furthermore, batteries nowadays can be charged rapidly, and the energy density per weight of the battery has increased considerably.

In spite of all this, one cannot ignore the fact that the electric car is far more grid-dependent than liquid fuel, which makes it unsuitable for use in probably most part of the world other than the industrialized countries. Furthermore, it is unlikely that commercial vehicles that must transport heavy loads and travel further than passenger cars can be powered by electricity stored in batteries.

Thus, our hope for electric cars to replace gasoline-powered cars by the mid 2020s must be viewed with a bag of salt--it probably won't happen, unless government mandates it.
Even then 80% of the world that constitute the non-industrialized countries are not going to mandate the replacement of gasoline-powered cars with electric cars for the simple reason that the internal combustion engine is the most grid-independent power plant amongst the available power plants for automobiles. In the part of the world where there is hardly any sort of energy supply grid, grid-independence is the critical factor in deciding the type of power plant to be in wide use.

To be sure, it is about time that mankind should come up with a replacement for the tremendously inefficient internal combustion engine, but that replacement must meet the fundamental functional characteristic of the internal combustion engine--its relatively grid-independent nature.
jimbo92107
4.7 / 5 (3) May 06, 2009
Toyota's iQ gets 65mpg. But it's not sold in the US.

Why?
Lord_jag
2.5 / 5 (2) May 06, 2009
The 1994 Geo Metro got 62 mpg at 70 mph when new, and mine was still getting over 50 mpg in late 2006, when an idiot pulled out in front of me and wrecked it! True, it wasn't a fancy car, but it took two of us and luggage across the country five times in relative comfort, and was perfect for driving to work and back, 20 miles each way, daily. Never mind fancy new designs, I want a new 94 Metro!


I had a geo metro for many years myself. It was an awesome car. 45mpg was the minimum I would ever get. It got me to work just fine. At 200,000 miles it started to burn oil so I got rid of it, but everything was cheap! Brakes cost me a whole $80 to replace all. Tires cost $100 for 4 brand new tires!

I want a brand new Geo Metro!
Nik_2213
4.3 / 5 (3) May 06, 2009
Sigh...

Never mind gas-guzzlers' fuel (in)efficiencies -- Though a modest raise in fuel tax might help there-- IIRC, this IC vs Electric issue was argued out decades ago...

You need cheerful hybrid cars that you can refuel with gas pump or spare can, but reclaim braking to the battery, and have range to commute / mall-run on battery alone.

Battery is not *huge*, may be modular with a variety or mix of tech. Smaller battery means smaller grid-load for plug-in re-charge.

IC may be a 'tiny', hyper-efficient Euro-engine, sixty-plus BHP from a litre or less.

Make them modular, so after-market can compete for efficiency and convenience, and customers can opt for different mixes of Electric / IC power & range...

Yeah, yeah, in my dreams...
wiyosaya
3 / 5 (3) May 06, 2009
I think it is interesting that some people seem surprised at the conclusions of this study. I am not surprised at all.

In fact, I heard a news story the other day where a former Chrysler exec was interviewed. He was remarking on the fact that the PT Cruiser will be discontinued this year.

These may not be his exact words, but he said something like "When the car was designed, there was no interest in pursuing fuel economy." He also said that an efficient engine could have been put in the car and the weight of the car could have been drastically reduced. Instead, what was produced was an overweight, inefficient piece of junk that appealed to people who think their car makes them "cool." Sad, very sad, IMHO.

Whether some of you like it or not, what this is emblematic of, IMHO, is unbridled capitalism. Where making a buck is more important than all else. The "big 3" in the US have had little interest in doing anything other than making cars as cheaply as possible, engineering them to fall apart, i.e., planned obsolescence, giving them far more "horsepower" than they need and selling that as "performance," and separating you from your money while making you think you have the greatest thing since perforated toilet paper.

No matter what, at this point, I refuse to buy an American car because I am not going to support an industry who's sole purpose is to sell me trash. IMHO, it is no wonder that the US auto industry is where it is. They are getting what they have given the US consumers, and they deserve it. It is too bad that we will likely get the same garbage after they get bailed out. The US should just let them fail, IMHO.

The Japanese auto industry has done far better, IMHO, however, I think that they are under the impression that they have to have models that are nearly identical to the same garbage that the US industry sells here. If any auto maker were to depart from the paradigm, I am willing to bet that they would be successful. Take the Prius, for instance.

At this point, though, I think we are stuck with a stagnant industry. Sooner or later, the US auto industry just might figure it out. However, if the almighty dollar bill is the driving force, I think it likely that they will fail again. At that point, I hope, the US should no longer bail them out.
Sirussinder
5 / 5 (3) May 06, 2009
What do you expect when the government keeps giving the big 3 billions of dollars to stay in business...STAGNATION!!

LET THE CAR COMPANIES DIE!!!

GARBAGE IN = GARBAGE OUT !!
david_42
3 / 5 (3) May 06, 2009
Rather than increased fuel economy, the last twenty years have seen a doubling of the base horsepower in cars from the Little 3. Any wonder that their market share has dropped. No one interested in improved mileage? Just a few million people buying imports every year. Very clever how the EPA was maneuvered into blocking small diesel vehicles, which would have made the decline of the Little 3 even faster.
KBK
3.4 / 5 (5) May 06, 2009
The interesting thing is that if you manage to get through the mental and communication barrier with individuals..almost every single person you know on this planet can find in themselves, somewhere...personal knowledge of suppressed (second to first hand info, ie, a friend says, 'my uncle knew this guy'), technologies that would have made gasoline, co2 emission issues and overall energy issues...obsolete nearly overnight.

Think about that for a few seconds.

If one looks for it, they can find lists of people that are 100's of names long..that have died, disappeared, been paid off, entire families and histories eliminated, etc, etc.... of the inventors of these technologies who have refused to bend to these control fanatics.

All you have to do is put in few days of serious effective searching....and this type of information will be abundantly clear to even the most adamant of naysayers.

After all, there would be no way anyone and any group (collusion) would try to stem the tide of alternative technologies, as they would only amount to about $1000US-1500US trillion worth of 'world change' in a very short time -that would have those who run the planet now--in a very different position.

I mean these people would not quietly collude to stop such things, now, would they?

Think about it for a few seconds. Use your head, your logic...not your emotions.
djp
3 / 5 (4) May 06, 2009
simple reason. If we used less of something, that something would be less needed. Now why would the manufacturers of this something allow this to happen?
DozerIAm
3.3 / 5 (3) May 06, 2009
...No one interested in improved mileage? Just a few million people buying imports every year.


American auto manufacturers cannot afford to build small, fuel efficient cars - the unit cost is too high on the labor side (due to union over compensation and over regulation by the government). So when the "Big 3" make a small, fuel efficient car, thay are about $2000 more expensive than manufacturers who are building with non-unionized labor. How do they make up the gap? By having lower quality control, lower quality parts, and by selling those cars at a lower margin of profit. People overall aren't fooled, so if they buy a small American car, it's usually their last one. You'll notice Honda and the other non "Big 3" automakers with manufacturing plants in the US chose areas outside Detroit, where labor was non organized and thus significantly less expensive. The sweet spot for American auto manufacturing is domestically the suv and truck market where the margins are higher. You'll also notice that GM plants abroad - which aren't hindered with American over-regulation and union level labor costs - are making quality small cars that are fuel efficient and profitable.
Lord_jag
5 / 5 (2) May 07, 2009
wiyosaya -
"Whether some of you like it or not, what this is emblematic of, IMHO, is unbridled capitalism. Where making a buck is more important than all else. "


But that's exactly the point. Did the PT Cruiser make money? Really? When you factor in the design cost and the retooling of a factory etc etc, did they make money? So why is GM failing if they are making money?

The problem is that they make cars that DON'T make money and capitalization is coming to bite them.

They need to get back to the bottom line and make cars that people really want to buy, not just a select few.
DozerIAm
4 / 5 (2) May 07, 2009
I would phrase it as they need to produce cars people want to buy because they are the best car or the most exciting car or the car that "speaks to them" in some intangible way - but not just because they are "American" cars". Unfortunately, I doubt the Big 3 can do that until CAFE standards are rolled back and the labor costs are reduced down to the actual value of the labor.
Jmaximus
not rated yet May 14, 2009
One could take the engine from a Cobalt and put it into a Model T and get triple the mileage. Americans don't drive open air Model T's though. They had all the safety features and comforts of a cheap gocart. Cars are heavier today because they are built like tanks for safety concerns, driven by lawsuits and mandates. A Geo Metro couldn't meet todays standards, let alone a death trap like the model t. There are so many reasons why this comparison is ignorant, but that is just one. It is like saying a new Quad core Intel PC is no better than a 286 because they both use about the same amount of power.

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