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Study of Hyundai/Kia fires points to small and turbocharged engines

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January 22, 2019

Study of Hyundai/Kia fires points to small and turbocharged engines

A high number of complaints about certain Hyundai and Kia models bursting into flames has prompted a recall campaign to fix faulty repairs that the affiliated companies say were carried out during previous recalls of 2011-14 Hyundai Sonatas, 2013-14 Hyundai Santa Fe Sports, 2011-14 Kia Optimas, 2012-14 Kia Sorentos and 2011-13 Kia Sportages.

Analysis by HLDI suggests that the companies are correctly targeting vehicles with small and/or turbocharged engines, though it's unclear whether their proposed remedy will eliminate the additional risk of fire that these models carry. HLDI research also points to an increased risk of fire for turbocharged engines generally, across brands.

In June, the Center for Auto Safety petitioned the National Highway Traffic Safety Administration to investigate potential defects in Kia Optima, Kia Sorento, Hyundai Sonata and Hyundai Santa Fe vehicles from certain model years. The petition, which pointed to a high number of reports of fires unrelated to collisions, prompted HLDI to examine noncrash fire claims for those vehicles in the data it receives from insurance companies.

HLDI found that rates of noncrash fire claims were significantly higher for the 2011-13 Kia Optima and Hyundai Sonata than for other midsize sedans. The 2011-15 Kia Sorento, 2012 Hyundai Santa Fe and the 2013-14 Hyundai Santa Fe Sport also had higher noncrash fire claim rates than other midsize SUVs. The Sportage, which wasn't part of the original petition, wasn't included in the analysis.

HLDI analysts shared these findings with NHTSA, and, based on those discussions, expanded the study to look at fire claim frequency by engine type. They found that the Hyundai and Kia vehicles with a 2.0-liter turbocharged engine had the highest frequency — 4.2 claims per 10,000 insured vehicle years — compared with 1.7 for the control vehicles. Hyundai and Kia models with a 2.4-liter engine also had an elevated noncrash fire claim frequency of 2.7. In contrast, Hyundai and Kia vehicles with a 3.3- or 3.5-liter engine had about the same rate of fire claims as the control group.

For vehicles with the 2.0-liter turbocharged and 2.4-liter engines, fire risk went up dramatically as the vehicles aged.

The two engines were the focus of the original recalls by Hyundai and Kia. They are both from the Theta II engine family, which is the subject of ongoing NHTSA investigations. The higher fire rates HLDI found could be related to an issue with this engine type.

It's also possible that there is something specific to the turbocharged engine causing additional fire risk in that variant. A separate HLDI study found that, across brands, turbocharged and supercharged engines have higher noncrash fire rates than nonturbocharged engines. Turbocharged engines use recycled exhaust to increase power, allowing a smaller engine to match the power of a larger nonturbocharged one.

On the other hand, the problem may be unrelated to the engine. Reports have also linked a large number of fires, including one in which a driver died, to the Kia Soul, and the Center for Auto Safety amended its original petition to add the 2010-15 Soul. The small car has a different type of engine from the vehicles that HLDI studied. The Soul wasn't part of Kia's earlier recall campaign and isn't named in the current one.

As news of the new recalls broke, NHTSA, which usually oversees such safety campaigns, was mostly closed due to the partial government shutdown. Hyundai and Kia said they would proceed anyway.

HLDI studies have helped NHTSA get to the bottom of such issues in the past. Last year, certain Smart ForTwo vehicles were recalled after HLDI found they had a much higher than normal noncrash fire claim frequency. The problem turned out to be connected to insulation in the engine compartment.

HLDI plans to continue looking at the issue and will add the Soul and the Sportage to any future studies.