A flexible-fuel vehicle (FFV) or dual-fuel vehicle
(colloquially called a flex-fuel vehicle) is an alternative fuel vehicle
with an internal combustion engine designed to run on more than one fuel,
usually gasoline blended with either ethanol or methanol fuel, and both fuels
are stored in the same common tank. Modern flex-fuel engines are capable of
burning any proportion of the resulting blend in the combustion chamber as fuel
injection and spark timing are adjusted automatically according to the actual
blend detected by a fuel composition sensor. Flex-fuel vehicles are
distinguished from bi-fuel vehicles, where two fuels are stored in separate
tanks and the engine runs on one fuel at a time, for example, compressed natural
gas (CNG), liquefied petroleum gas (LPG), or hydrogen.
The most common commercially available FFV in the world
market is the ethanol flexible-fuel vehicle, with about 39 million automobiles,
motorcycles and light duty trucks manufactured and sold worldwide through
October 2013, and concentrated in four markets,
Brazil (23.0 million), the United States (15 million), Canada (more
than 600,000), and Europe, led by Sweden (229,400). The Brazilian flex fuel fleet includes over
3 million flexible-fuel motorcycles produced since 2009 through October
2013. In addition to flex-fuel vehicles running with ethanol, in Europe and the
US, mainly in California, there have been successful test programs with
methanol flex-fuel vehicles, known as M85 flex-fuel vehicles. There have been
also successful tests using P-series fuels with E85 flex fuel vehicles, but as
of June 2008, this fuel is not yet available to the general public. These
successful tests with P-series fuels were conducted on Ford Taurus and Dodge
Caravan flexible-fuel vehicles.
Though technology exists to allow ethanol FFVs
to run on any mixture of gasoline and ethanol, from pure gasoline up to 100%
ethanol (E100), North American and European flex-fuel vehicles are optimized to
run on a maximum blend of 15% gasoline with 85% anhydrous ethanol (called E85
fuel). This limit in the ethanol content is set to reduce ethanol emissions at
low temperatures and to avoid cold starting problems during cold weather, at
temperatures lower than 11 °C (52 °F). The alcohol content is reduced
during the winter in regions where temperatures fall below 0 °C
(32 °F)]
to a winter blend of E70 in the U.S. or to E75 in Sweden from November until
March. Brazilian flex fuel vehicles are optimized to run on any mix of E20-E25
gasoline and up to 100% hydrous ethanol fuel (E100). The Brazilian flex
vehicles are built-in with a small gasoline reservoir for cold starting the
engine when temperatures drop below 15 °C (59 °F). An improved flex
motor generation was launched in 2009, which eliminated the need for the
secondary gas tank
Most people
think that flex fuel vehicles are a fairly new technology, as in the last ten
years. Actually, the first commercial flexible fuel vehicle was the Ford Model
T, produced from 1908 through 1927. It was fitted with a carburetor with
adjustable jetting, allowing use of gasoline or ethanol, or a combination of
both. Other car manufactures also provided engines for ethanol fuel use. Henry
Ford continued to advocate for ethanol as fuel even during the prohibition.
However, cheaper oil caused gasoline to prevail, until the 1973 oil crisis
resulted in gasoline shortages and awareness on the dangers of oil dependence.
This crisis opened a new opportunity for ethanol and other alternative fuels,
such as methanol, gaseous fuels such as CNG and LPG, and also hydrogen. Ethanol,
methanol and natural gas CNG were the three alternative fuels that received
more attention for research and development, and government support.
Since 1975,
and as a response to the shock caused by the first oil crisis, the Brazilian
government implemented the National Alcohol Program -Pró-Álcool- (Portuguese: Programa Nacional do Álcool), a
nationwide program financed by the government to phase out automotive fuels
derived from fossil fuels in favor of ethanol made from sugar cane. It began
with a low blend of anhydrous alcohol with regular gasoline in 1976, and since
July 2007 the mandatory blend is 25% of alcohol or gasohol E25. In 1979, and as
a response to the second oil crisis, the first vehicle capable of running with
pure hydrous ethanol (E100) was launched to the market, the Fiat 147, after
testing with several prototypes developed by Fiat, Volkswagen, GM and Ford The
Brazilian government provided three important initial drivers for the ethanol
industry: guaranteed purchases by the state-owned oil company Petrobras,
low-interest loans for agro-industrial ethanol firms, and fixed gasoline and
ethanol prices. After reaching more than 4 million cars and light trucks
running on pure ethanol by the late 1980s, the use of E100-only vehicles
sharply declined after increases in sugar prices produced shortages of ethanol
fuel.
After
extensive research that began in the 90s, a second push took place in March
2003, when the Brazilian subsidiary of Volkswagen launched to the market the
first full flexible-fuel car, the Gol 1.6 Total Flex. Several months later was
followed by other Brazilian automakers, and by 2010 General Motors, Fiat, Ford,
Peugeot, Renault, Volkswagen, Honda, Mitsubishi, Toyota, Citroën, Nissan and Kia
Motors were producing popular models of flex cars and light trucks. The
adoption of ethanol flex fuel vehicles was so successful, that production of
flex cars went from almost 40 thousand in 2003 to 1.7 million in 2007. This
rapid adoption of the flex technology was facilitated by the fuel distribution
infrastructure already in place, as around 27,000 filling stations countrywide
were available by 1997 with at least one ethanol pump, a heritage of the Pró-Álcool
program.
In the United States, initial support to
develop alternative fuels by the government was also a response to the first
oil crisis, and some time later, as a goal to improve air quality. Also, liquid
fuels were preferred over gaseous fuels not only because they have a better
volumetric energy density but also because they were the most compatible fuels
with existing distribution systems and engines, thus avoiding a big departure
from the existing technologies and taking advantage of the vehicle and the
refueling infrastructure. California led the search of sustainable alternatives
with interest focused in methanol.
Ford Motor Company and other
automakers responded to California's request for vehicles that run on methanol.
In 1981, Ford delivered 40 dedicated methanol fuel (M100) Escorts to Los
Angeles County, but only four refueling stations were installed. The biggest
challenge in the development of alcohol vehicle technology was getting all of
the fuel system materials compatible with the higher chemical reactivity of the
fuel. Methanol was even more of a challenge than ethanol but much of the early
experience gained with neat ethanol vehicle production in Brazil was
transferable to methanol. The success of this small experimental fleet of M100s
led California to request more of these vehicles, mainly for government fleets.
In 1983, Ford built 582 M100 vehicles; 501 went to California, and the
remaining to New Zealand, Sweden, Norway, United Kingdom, and Canada.
As an answer to the lack of refueling
infrastructure, Ford began development of a flexible-fuel vehicle in 1982, and
between 1985 and 1992, 705 experimental FFVs were built and delivered to
California and Canada, including the 1.6L Ford Escort, the 3.0L Taurus, and the
5.0L LTD Crown Victoria. These vehicles could operate on either gasoline or
methanol with only one fuel system. Legislation was passed to encourage the US
auto industry to begin production, which started in 1993 for the M85 FFVs at
Ford. In 1996, a new FFV Ford Taurus was developed, with models fully capable
of running on either methanol or ethanol blended with gasoline. This ethanol
version of the Taurus became the first commercial production of an E85 FFV. The
momentum of the FFV production programs at the American car companies
continued, although by the end of the 1990s, the emphasis shifted to the FFV
E85 version, as it is today.
Ethanol was preferred over methanol
because there is a large support from the farming community, and thanks to the
government's incentive programs and corn-based ethanol subsidies available at
the time. Sweden also tested both the M85 and the E85 flexifuel vehicles, but
due to agriculture policy, in the end emphasis was given to the ethanol
flexifuel vehicles. Support for ethanol also comes from the fact that it is a biomass
fuel, which addresses climate change concerns and greenhouse gas emissions,
though nowadays these benefits are questioned and depend on the feedstock used
for ethanol production and their indirect land use change impacts.
The demand
for ethanol fuel produced from field corn in the United States was stimulated
by the discovery in the late 90s that methyl tertiary butyl ether (MTBE), an oxygenate
additive in gasoline, was contaminating groundwater. Due to the risks of
widespread and costly litigation, and because MTBE use in gasoline was banned
in almost 20 states by 2006, the substitution of MTBE opened a new market for
ethanol fuel. This demand shift for ethanol as an oxygenate additive took place
at a time when oil prices were already significantly rising. By 2006, about 50
percent of the gasoline used in the U.S. contained ethanol at different
proportions, and ethanol production grew so fast that the US became the world's
top ethanol producer, overtaking Brazil in 2005. This shift also contributed to
a sharp increase in the production and sale of E85 flex vehicles since 2002.
Since 1998 a total of 15.1 million E85
flex-fuel vehicles had been sold or lease in the United States through December
2012. Of these, about 11 million flex-fuel cars and light trucks were still in
operation as of early 2013, up from 7.3 million in 2008, 4.1 million in 2005,
and 1.4 million on U.S roads in 2001. For the 2011 model year there are about
70 vehicles E85 capable, including sedans, vans, SUVs and pick-up trucks. Many
of the models available in the market are trucks and sport-utility vehicles
getting less than 20 mpg-US
(12 L/100 km; 24 mpg-imp)
when filled with gasoline. Actual consumption of E85 among flex-fuel vehicle
owners is limited. Nevertheless, the U.S. Department of Energy estimated that
in 2009 only 504,297 flex-fuel vehicles were regularly fueled with E85, and
these were primarily fleet-operated vehicles. As a result, from all the ethanol
fuel consumed in the country in 2009, only 1% was E85 consumed by flex-fuel
vehicles.
Certain information for this article was
sourced from Wikipedia.org.
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