Shares of New York-listed Ford and Firestone's parent, Tokyo-listed Bridgestone, have had a rocky ride over the past month, as investors tried to measure the financial fallout from the recall of 6.5 million tires.

It was just about one month ago (August 9) that Japanese tire maker Bridgestone announced a recall of defective tires linked to at least 88 deaths in the United States.

Most of the recalled tires are on Ford vehicles, especially its popular Explorer sport utility vehicles.

Since the recall, shares of Bridgestone have been severely punished, plummeting to almost half of their value reached earlier this year on the Tokyo Stock Exchange.

Bridgestone said it will record a one-time $350 million US accounting charge on its earnings to cover the costs of the recall, and that earnings will be reduced by about 26 per cent for the year.

Some analysts warn that the tragedy might eventually lead to the disappearance of the Firestone brand altogether.

The costs could also mount as U.S. safety regulators continue their investigation into the accidents.

Also, Venezuela's consumer protection agency is pushing for Bridgestone and Ford to be criminally prosecuted over tires linked to 46 deaths in Venezuela.

Bridgestone has kept quiet about the tragedy. It has held only one company news conference about the recall on August 10.

On Wednesday, U.S. lawmakers grilled the chief executive of Bridgestone, Masatoshi Ono. He said he still did not know what caused his company's tires to fail in accidents, but that the company would continue to investigate the cause.

Many of the accidents involve Ford's Explorer rolling over, and Ford believes that the problems are linked to faulty tires rather than problems with the vehicle itself.

Analysts seem to agree that the financial brunt of the recall rests on the shoulders of Bridgestone, and not Ford. Consequently, shares of the auto maker have started to claw their way back from 52-week lows, with analysts believing that most of the bad news is behind.

In the meantime, hundreds of thousands of Canadians are schlepping to their Ford dealerships to have their SUV's tires replaced.

Whether its Firestone or Ford that pays, the bill is escalating, with replacement tires costing about $150 each, with four tires plus a spare per vehicle. The cost for Ford vehicles could easily surpass $212 million in Canada alone.