"As our development of the enablers and computer controls continues, we'll extend the H.C.C.I. operating range up and down the load range," Mr. Alt said.
But Ms. Spagnoli said that all of the Load Range E tires used the same basic construction and therefore should be treated as a group.
Charles Sinclair, a Goodyear spokesman, said that the tire-related deaths had been spread among 10 different sizes and types of Goodyear Load Range E truck tires.
In Goodyear's case, many of the questions center on how the company went about adding protective nylon layers to its Load Range E tires.
The replacement offer was limited to a portion of Goodyear Load Range E tires because of a government warning last year that 15-passenger vans had an increased risk of rolling over under some conditions.
Adding the layers to all 43 lines of Load Range E tires took four years partly because "to put an overlay in some cases takes different equipment," he said.
Charles Sinclair, a Goodyear spokesman, said that there had been no deaths on tires with the nylon layers but that only 10percentt of the Goodyear Load Range E tires produced over the last decade had the nylon layers anyway.
Tire production data provided by Goodyear today appeared to indicate that the death rate associated with its Load Range E tires is considerably lower than the average for all tires.
"The company constantly monitors the performance of its tires and is confident that, put in proper perspective, all of Goodyear's Load Range E tires on the road today have excellent durability and performance," the company said in a statement.
The offer covers 15-seat passenger vans and ambulances and will resolve a 15-month investigation of 21 million Goodyear Load Range E tires by the National Highway Traffic Safety Administration, an agency spokesman, Rae Tyson, said.
The National Highway Traffic Safety Administration began a so-called preliminary evaluation, its lowest level of review, after receiving reports of 15 deaths and 129 injuries linked to Goodyear 16-inch Load Range E tires over the last five years.
