Minor accidents that would have caused no damage to a 1981 small car can bring a big repair bill for 1989 models, according to insurance industry tests.

The Insurance Institute for Highway Safety intentionally crashed 19 new 1989 two-door cars at 5 mph into two flat barriers, once going forward and once backward, and then bumped the front end of each car into an angle barrier and the back end into a post.Damage estimates calculated in January ranged from $3,445 for an Isuzu Impulse to $434 for a Geo Spectrum.

Identical tests on a new Ford Escort in 1981 caused no damage, institute spokesman Brian O'Neill said Thursday.

A 1989 Ford Escort suffered no damage in the straight-on barrier tests but the repair cost after the other two tests totaled $1,481.

O'Neill said the low-speed tests were conducted over the past month at test facilities in Hartwood, Va., using new cars purchased anonymously by the institute, which is financed by the insurance industry.

The highest repair estimates were for the Isuzu Impulse, the Daihatsu Charade at $3,047 and the Honda CRX HF at $3,040. The least damaged cars after the Geo Spectrum were the Toyota Corolla with $495 in damage and the Plymouth Colt with $642.

Prior to the 1983 model year, federal law required that cars sustain no damage in 5 mph front and rear barrier tests. For newer models, the standard was lowered to 2.5 mph.

Nine cars sustained no damage at all in the front and rear barrier tests in the 1989 study but all were damaged when nudged up against the angle barrier and pole.

Ford Motor Co. spokeswoman Joyce Stinson said the difference in damage to the Escort is due to changes in the model that include a lightweight bumper to help Ford meet federally imposed mileage standards. Lighter cars use less gas.

She said the pole and angle tests are "very tough" but Ford has voluntarily built other models to comply with the pre-1983 standard for straight-on barrier crashes rather than the less-stringent 2.5 mph standard.

A spokesman for Isuzu, Dan McCue, said the company had requested documentation on the testing and would not respond until it could study the material.

Kurt Antonius, spokesman for American Honda in Los Angeles, said the CRX HF model is designed for fuel economy with a lighter bumper but other Honda models have stronger bumpers than last year.

"The most important thing is that this is not related to auto safety," he said. The tests did not cover any injuries that might occur to driver or passengers in low-speed crashes.

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(chart) How they compare

Here's a list of new two-door cars in 5 mph crash tests with total dollar damage in four tests. Tests all were on 1989 models except where noted:

Isuzu Impulse $3,444

Daihatsu Charade $3,047

Honda CRX HF '88 $3,040

Chrysler Conquest $2,357

Pontiac LeMans '88 $2,144

Plymouth Sundance $2,117

Volkswagen Jetta '88 $2,105

Honda CRX $2,061

Volkswagen Fox '88 $1,887

Volkswagen GTI $1.875

Ford Festiva L '88 $1,849

Acura Integra LS '88 $1,763

Dodge Daytona ES $1,754

Saab 900 $1,673

Volkswagen Gulf '88 $1,655

Geo Metro Coupe $1,620

Ford Probe GL $1,592

Mercury Tracer '88 $1,571

Dodge Daytona $1,545

Nissan 240 SX SE $1,531

Ford Escort LX $1,481

Mazda MX-6 DX '88 $1,465

Honda Civic 3Dr $1,262

Nissan Pulsar NX '88 $1,248

Volkswagen Cabriolet $1,144

Toyota MR2 $1,091

Toyota Tercel EZ '88 $1,001

Mazda 323 '88 $934

Hyundai Excel GL '88 $842

Mitsubishi Mirage Tbo $824

Plymouth Colt $642

Toyota Corolla '88 $495

Geo Spectrum '88 $434