NEW YORK (CNNMoney.com) -- Toyota challenged a California driver's story of an out-of-control Prius at a press conference Monday afternoon.
Company executives detailed preliminary findings of a joint investigation conducted by Toyota and the National Highway Traffic Safety Administration into the incident.
Prius owner Jim Sikes made national headlines last week with claims that his car's accelerator got stuck as he sped up to pass a car while traveling on California's I-8 highway outside of San Diego, and that he was unable to stop the car.
"As I was going, I was trying the brakes ... and it just kept speeding up," he said.
Sikes story is at odds with the findings of the investigation, according to Toyota and to a draft congressional memo obtained by CNN.
"While a final report is not yet complete, there are strong indications that the driver's account of the event is inconsistent with the findings of the preliminary analysis," Toyota said in a prepared statement.
Sikes said he called 9-1-1 for help as he was traveling in excess of 90 mph on a winding, hilly portion of the interstate. He said dispatchers tried to talk him through ways to stop the car, but nothing helped.
Eventually, a California Highway Patrol officer was able to catch up to Sikes and used the patrol car's public address system to instruct Sikes to apply the brakes and the emergency brake at the same time. That tactic worked, and he was able to stop the car.
However, because driving a hybrid car like the Prius with both the gas pedal and the brakes simultaneously depressed would cause serious damage to the car's electric motor and, possibly other systems, Toyota says the Prius is designed to prevent that from happening.
If the brake is pressed at the same time as the gas pedal, power to the engine will be reduced just as if the gas pedal had been released, the automaker said. During driving tests on Sikes' Prius and on an identical 2008 Prius, the system operated as expected, according the report, preventing the car from pushing forward while braking.
Investigators are extremely meticulous when taking apart a car in a case like this, said Ed Higgins, a Michigan personal injury attorney who has been involved in automobile defect cases. They are aware their work will be subject to intense scrutiny, so they measure and document everything, he said.
"I would think that any mechanical defect that would have allowed something to happen that otherwise could not have happened would have stood out like a sore thumb," he said.
The car also did not show damage consistent with the engine having been running at full throttle while the brakes were on, according to the report.
"Toyota engineers believe that it would be extremely difficult for the Prius to be driven at a continuous high speed with more than light brake-pedal pressure, and that the assertion that the vehicle could not be stopped with the brakes is fundamentally inconsistent with basic vehicle design and the investigation observations," Toyota said in a statement.
The car's front brakes showed significant wear and overheating, Toyota said. That kind of wear and heat would be consistent with the brakes being lightly applied over a long period of time, executives said at the press event.
Data from on-board computers indicated that Sikes had applied the brakes, to some degree, at least 250 times during the 23 mile incident, Toyota executives said, and that the brakes worked normally each time.
Edmunds.com has independently tested Prius cars similar to Sikes' and confirmed that the engine would stay engaged if the brakes were only pressed lightly, but not hard enough to actually stop or slow the car, said Dan Edmunds, head of auto testing for the automotive Web site Edmunds.com.
"If you're just riding the brakes, it will ride the brakes," he said.
"These findings certainly raise new questions surrounding the veracity of the sequence of events that has been reported by Mr. Sikes," said Kurt Bardella, spokesman for Rep. Darrell Issa, R-Calif., and ranking member of the committee.
Sikes' attorney, John Gomez, denied that the report proves his client was wrong about what happened to his car.
"The notion that they weren't able to replicate it in this particular case tells us nothing," he said. "They haven't been able to replicate a single one of these."
Sikes has no plans to sue Toyota, Gomez said.
Gomez is also representing the family of Mark Saylor, a California Highway Patrolman who was killed, along with members of his family in a Lexus sedan that accelerated out of control. A preliminary investigation has found that the accelerator pedal in that car probably became trapped on an all-weather floor mat that had been incorrectly installed in the vehicle.
Toyota has issued a recall for several models, including Sikes' Prius, to address possible floor mat entrapment. Sikes' floor mat was not interfering with the accelerator, investigators found, and there were no signs the pedal had become stuck in any way, according to the report.
The investigators findings "suggest that there should be further examination of Mr. Sikes account of the events of March 8," Toyota said in its statement.
Toyota spokesman Mike Michels also took issue with media coverage of the Sikes incident. Journalists sensationalized an admittedly dramatic event, he said, but the public would have been better served had reporters waited for all the facts.