IAG is calling on car manufacturers to improve bumper bar design after crash tests revealed high repair costs even at low speeds.

Subsidiary companies NRMA Insurance and SGIO tested nine of Australia's top-selling small cars in a simulated 10kmh collision - the most common type of accident.

The Honda Civic sedan was the most expensive to repair at $7386, or 31% of its total value. The Suzuki Swift five-door hatch was next at $5547 (35%).

The Toyota Corolla five-door hatch was the top performer, with a repair cost of $1019 (4.4%).