Firestone has found in tests that the left-rear tires on Ford Explorers become hottest of all during routine driving, he said.
That is why accidents involving Firestone tires on Ford Explorers were unusual, he said.
It is embroiled in a $3 billion recall of Firestone tires on Ford Explorers.
Firestone included an extra liner in its product and this was then also used to replace tires on Ford Explorers.
Most tires being recalled were supplied as original equipment on Ford Explorers, the most popular sport utility vehicle.
In 1996, several state agencies in Arizona began having big problems with Firestone tires on Ford Explorers.
More than 60 deaths have been caused by blowouts on Ford Explorers on Venezuelan highways, government officials say.
Ford has increasingly blamed Firestone for the tire problems, which have mainly occurred on Ford Explorers.
The move is an unusually swift reaction to the failure of industry and regulators to recognize a problem with Firestone tires on Ford Explorers.
One of the most publicized of all recent recalls was for Firestone tires on Ford Explorers.