Federal traffic safety chief Joan Claybrook announced plans to require auto makers to place tamper-resistant odometers in their new cars beginning in 1980 as part of an effort to combat what she called "the billion-dollar fraud" of turning back milleage figures on autos at the time of sale.

The rules would set new requirements on the accuracy of speedometers and odometers, and provide for some form of indication when a car's odometer passes 100,000.

Claybrook said the national highway traffic safety administration regulations also call for speedometers on 1980 model cars to read only to a maximum of 85 miles an hour. And, she wants the 55 mph reading on the speedometer to be highlighted to remind drivers to observe the national speed limit.

Claybrook said there were two major effects of odometer tampering, which would become a federal crime under the proposal.

"Someone who purchases a car that they think has only gone 20,000 miles presumes that it is in far better shape than in fact it is if it has gone 60,000 miles," she said. "So they might not check the brakes or have the car overhauled or do any of those things that you would do if the car were older - and that's a safety hazard."

"Secondly, people lose a lot of money," she added. "One of the cheapest wasy to manufacture money is to turn the odometer back. The fraud involved is in the billion-dollar range, and I wouldn't be surprised if it was far in excess of that."

Claybrook said the auto industry "has no reason not to support the measure," which would require vehicle dealers and distributors to retain mileage disclosure statements issued by and to them for four years.

The regulations also would call on states to include odometer information on state certificates of title.

In addition to the odometer rules, Claybrook said that, within a month, she expected the NHTSA to propose new standards aimed at making it harder to steal a car.

Claybrook said "the annual cost to society of auto theft is conservatively estimated at over one billion dollars, but a recent study puts the cost between $2.6 and $3.6 billion." There is a need for more protection against theft, she added.

She said her proposals "would make it much more difficult for thieves to hot-wire ignition systems, jimmy door locks, duplicate ignition keys and get under the hood of a vehicle."

"We are concerned, of course, with vehicle theft and its relation to safety because stolen cars are involved in accidents at a phenomenal rate - something like 220 times the normal accident rate," she added.

Some auto makers have taken their own steps to combat theft, Claybrook said. She singled out Ford Motor Co. for developing a door-lock button that is so rounded at the top that a coat hanger put through a window crack cannot hook it and open the door.

She also said that other possible mandated security improvements might include special latches that only allow a hood to be opened from inside the car and separate keys for the ignition and door-locks.

The fines against auto amkers for violating any of the federal safety regulations that are approved can run up to $1,000 a vehicle, up to a total of $800,000.

Although representatives of Ford and General Motors Corp. attended the press conference, held at the Department of Transportation, neither would comment on the proposals.