05-11-2002
ENERGY: 40 Miles Per Gallon in an SUV?
The SUV: No longer just a vehicle, it has been held up as a gas-guzzling
beast by some and as an all-weather family friend by others. But is it
possible to have a roomy, safe, suburban utility vehicle with all of
today's features that is also fuel-efficient? Members of the Union of
Concerned Scientists say yes, because the technology exists. But without
the government's help, they say, such a vehicle may not hit the
road.
In 1975, lawmakers passed corporate average fuel economy (CAFE) standards
that required an automaker's vehicles to average 27.5 miles per gallon.
But they exempted light trucks, a category that includes SUVs, pickup
trucks, and minivans. As a group, those vehicles must average 20.7
mpg.
Fast-forward to March 2002, when the Senate dealt environmental groups a
blow by striking down a bill that sought to raise the average fuel-economy
of all vehicles to 36 mpg by 2015. Instead, the Senate enacted a provision
giving the Transportation Department two years to review the existing CAFE
standards.
SUVs are on the low end of the fuel-economy scale; many have mileage rates
in the mid-teens. The problem with this low mileage, environmentalists
contend, is twofold: Each extra gallon of gas burned increases consumer
reliance on foreign oil and produces carbon dioxide, which, scientists
say, contributes to global warming.
But SUV sales are soaring. Between 1980 and 1999, the light-truck market
share in the United States rose from 22 to 50 percent of vehicle sales,
according to the Alliance of Automobile Manufacturers. In 2000, SUVs made
up one-fifth of all passenger-vehicle sales. And a Maritz Research survey
shows that, on a scale of features that new-car buyers want, fuel-economy
ranks just 25th-well below safety, comfort, and space.
Nevertheless, fuel-efficiency technologies have been advancing. Already on
the road are two small-scale hybrid gasoline-electric cars, Honda's
Insight and Toyota's Prius. Both can exceed 50 mpg. Hybrids are powered by
a conventional engine and an energy-saving electric motor. In addition,
Honda just introduced a hybrid Civic.
Larger hybrids aren't far behind. The first hybrid compact SUV expected on
the road is the Ford Escape HEV, due to start production in 2003. For its
4x2, Ford is targeting 40 mpg for city driving and 29 on the
highway.
But UCS analysts say automakers could double the fuel-efficiency of their
SUV fleet with today's technology. In 1999, using the popular 19.3-mpg
Ford Explorer as a model, the group designed its own SUV that reached 28.4
mpg. Last year, the researchers updated the plans and achieved 40 mpg in a
nonhybrid. A study by the National Academy of Sciences concurred that
raising CAFE standards is feasible from a technology standpoint.
According to UCS Senior Analyst David Friedman, these currently available
technologies include:
* An engine with variable valve timing, which helps get air and fuel
inside more efficiently.
* Displacement on demand, which is an 8-cylinder engine developed by
General Motors that can shut off half its cylinders when the car is
cruising.
* Integrated starter-generators, which allow an idle vehicle to shut down
its engine and start it up again quickly.
* A continuous variable transmission, which rather than relying on four or
five gears, has an infinite number of gear ratios that keep the engine at
its most efficient.
In addition to these improvements, UCS researchers recommend
low-rolling-resistance tires and a "unibody" construction to
reduce vehicle weight. Combine all that with today's hybrid technology and
tomorrow's hydrogen fuel cells and "you can go even further,"
Friedman says.
But won't the fuel-efficient SUV sacrifice power, size, and even
attractiveness? Not, Friedman says, if "you keep performance where it
is today." He says automakers' efforts have been going into
"power and speed and weight. Without regulations driving fuel-economy
higher, technology is instead being used to beef up vehicles on the
road."
AAM's Eron Shosteck disagrees. Some of the fuel-saving technology, he
says, is "not feasible from a cost or safety standpoint." As an
example, he cites the low-rolling-resistance tires, which he says create
winter driving worries because they don't adhere to the road as well as
standard SUV tires.
And cost is certainly a factor. Both sides acknowledge that adding these
features would add thousands to the price of an SUV. Friedman, however,
estimates that at least twice the additional amount spent at purchase
could be saved on gas over the life of the car.
Whether these technologies will ever combine to create an SUV with the
fuel-efficiency of a compact car depends a lot on the CAFE standards that
the Transportation Department devises in the next two years. Until then,
the two sides will continue to drive the debate.
Erin Heath
National Journal
