Mini-cars, the two-seat vehicles becoming popular withfuel-conscious auto buyers, fared poorly in real life crashsituations, according to the Insurance Institute for HighwaySafety.

In a recently released report, the IIHS said in tests with threemini-cars crashing into larger cars, occupants would sustain severeinjury or death because the minis lack the physical barrier largercars provide.

The tests involved three mini-cars–the Honda Fit, Daimler'sSmart Fortwo and Toyota Yaris–and their midsize model sisters. Thecars crashed into one another at a speed of 40 mph in head-oncollisions.

All three minis earned good frontal crashworthiness ratings inthe offset test into deformable barriers, but when they crashedinto heavier vehicles the cars did not fare as well.

“Though much safer than they were a few years ago, mini-cars asa group do a comparatively poor job of protecting people incrashes, simply because they're smaller and lighter,” Adrian Lund,IIHS president, said in a statement.

In a match-up between the Honda Accord and Fit, the Accord “heldup well,” but the Fit was “less than good” with a high risk of leginjury.

In the Mercedes C class vs. the Smart Fortwo test, the Smart“went airborne and turned around 450 degrees” when it hit the Cclass. The injuries in the Smart were judged to be “poor” with thelikelihood of injury to head and legs. The C class “held up well”with injury likelihood in the “good” range.

The description of potential injury in the Yaris appeared to beclose to cataclysmic. The car's door was torn away, driver's seattipped forward and the steering wheel “moved excessively.” The testdummy's head struck the car's steering wheel through the airbags,earning a poor rating for head protection. There were alsoextensive indications of neck and leg injuries. The Camry was ratedacceptable.

All three mini-cars earned a “poor” rating in the car-to-cartest.

Statistically, even though the mini-cars' safety has improved,minis that were one-to-three years old had a death rate of 35 permillion for single-vehicle crashes in 2007, compared to 11 permillion for very large cars, the IIHS said.

The IIHS said fuel efficiency standards can be improved withoutsacrificing safety with mini-cars through better use of technologyand reduction of the speed limit, which both reduces gasconsumption and decreases accidents.

Automakers should be forced to use “engine-enhancing technologyto improve fuel efficiency instead of to boost performance,” saidthe IIHS in its report. Not only would cars be more fuel efficient,but the less powerful cars would be safer to drive.