Madison (WI) - Americans are in love with their SUVs and even gas prices topping $3 per gallon aren't convincing enough for many to consider more fuel efficient cars. And probably they don't have to, if a research project at the University of Wisconsin-Madison makes its way into mass-production.

Roland Piquepaille has picked up in his Technology Trends blog a press release about a Chevrolet Equinox small SUV that has been modified as part of the Challenge X, which interestingly has been sponsored by Chevrolet - a company that is not really known to build the most fuel efficient cars around. What is special about this Equinox is that it is a hybrid vehicle, which combines an electrical engine to power the rear wheels and a diesel engine powering the front wheels.

Hybrids aren't new, but the concept of the University of Wisconsin-Madison has a few unique approaches. First, instead of a regular gasoline engine that is used, for example, in the Ford Escape Hybrid or Lexus RX400h Hybrid it uses a diesel engine that provides not only more torque but are also more fuel efficient at higher speeds - a discipline where today's available hybrid cars still disappoint. The first diesel-hybrid concept was shown last year by French auto maker Citroen, which promised to bring the car to the European market in the 2008 time frame.

Second, while electric engines in today's hybrids are often used to just start the car (a concept shown by Audi), to boost torque and to be active mainly a slower speeds, the electric motor Challenge X concept's Equinox runs all the time.

The creators of the vehicle, named "Moovada," claim that the new powertrain increases the Equinox' fuel efficiency by more than 50% to about 35 mpg, up from 15-20mpg. The cost to install the system into a stock car would be about $3000 - $5000, according to Liz Casson, team leader for the engineering student group. "Fuel prices would need to be around $4 per gallon for consumers to recapture their investment," she said.

Combining the most fuel-efficient engine out there today with the benefits appears to be a no-brainer these days. But car makers still have to invest lots of time and money into educating the US mainstream buyer that diesel engines aren't as bad as 20 years ago. And perhaps, car makers will also find out that hybrid technology may not just be great for enhancing a V6 engine to get V8 power at V6 fuel efficiency, but to create a vehicle with today's horsepower range and tomorrow's fuel efficiency requirements as well.

Source : Tom's Hardware US