By Bernie Woodall
DETROIT (Reuters) - A probe into the risk of fire after a rear-impact crash for older model Chrysler Group Jeep vehicles has been raised a step closer to a possible recall and expanded to include a total of about 5.1 million vehicles, U.S. safety regulators said on Thursday.
The expanded probe includes about 3 million 1993-2004 Jeep Grand Cherokee SUVs, 1.1 million 1993-2001 model year Jeep Cherokee SUVs and about 975,000 2002-2007 Jeep Liberty SUVs.
Nearly two years ago, the U.S. National Highway Traffic Safety Administration opened a preliminary investigation into the possible extraordinary fire risk of 3 million Jeep Grand Cherokee SUVs in the event of a rear-end collision. On Thursday, NHTSA raised the level of that probe to an engineering analysis and expanded it to include the other two Jeep SUV models.
Chrysler's primary executive liaison with U.S. federal regulators, Dave Dillon, said that the risk of fire is not higher among the three models than for comparable models from other automakers, and that the models are safe.
"The vehicles are absolutely safe," said Dillon in an interview.
However, on its website on Thursday, the regulator said, "NHTSA's assessment of the data collected during preliminary evaluation indicates that rear-impact-related tank failures and vehicle fires are more prevalent in the Jeep Grand Cherokee than in the non-Jeep peer vehicles."
The action by NHTSA is short of a recall but may lead to one. A probe goes to engineering analysis from a preliminary investigation when NHTSA officials want to analyze an issue more completely before deciding to ask that the manufacturer conduct a recall.
Chrysler Group, majority-owned by Fiat SpA, no longer makes the Jeep Cherokee, but the Grand Cherokee and Liberty remain two of Jeep's best-selling models.
NHTSA's investigation began in 2010 almost a year after consumer watchdog group The Center for Auto Safety contended that the Grand Cherokee fuel tank storage system was defective and posed a hazard in a crash, in part because its fuel tank is located behind the rear axle, which it said increased the chance of leaks and fire risk after a crash.
Chrysler's Dillon said the fire risk is not higher than in competitive vehicles from other manufacturers and the fact that Jeep moved the Grand Cherokee's fuel tank to in front of the rear axle in models since the 2005 model year was due to a design change and not because previous models were not as safe.
NHTSA reported that through 2010 Jeep Grand Cherokee vehicles had been involved in crashes with fires that led to 15 deaths and 46 injuries. The regulator offered no similar figures for the other two Jeep models involved in the engineering analysis.
Chrysler is, as automakers normally do when an investigation is ongoing, supplying NHTSA with its own research and evidence that a recall should not be undertaken. Recalling millions of vehicles is a costly endeavor, but Chrysler did not say how much such a recall could cost nor how much the automaker has spent on its evaluation so far of the fire risk issue.
Dillon said Chrysler researchers found fewer crashes leading to fire in Grand Cherokees than those of other automakers after analyzing 21,322 accident reports from three U.S. states from 2000 through 2008.
The states, Florida, Illinois and North Carolina were chosen because they are large states where data could be sorted to include crashes that required that the vehicle be towed away, which yields a much larger sample than NHTSA's analysis of fatal accidents.
Those reports involved rear-end collisions of 1993-2004 Grand Cherokees and similarly aged peer SUVs Chevrolet Blazer from General Motors Co, Ford Motor Co's Explorer and the Toyota Motor Corp 4runner.
The incidence of fire was shown to be "extremely rare" for all of the models tested, and "almost always involve rear impacts so severe that no fuel system design in any vehicle could reasonably be expected to guarantee against fuel leakage or fire," Chrysler said in a research paper given to NHTSA.
The incidence of fire in the 21,322 rear-impact crashes ranged from 0.19 percent of rear-impact crashed for the Grand Cherokee to 0.33 percent for the Chevy Blazer, Chrysler said.
NHTSA said that the number of affected vehicles on U.S. roads is less than 5.1 million due to attrition, but offered no alternative figure.
(Reporting By Bernie Woodall; Editing by Alden Bentley and Sofina Mirza-Reid)