They were both rated best picks by the insurance institute.
A lack of data means that the insurance institute has not yet performed similar studies for stability control.
The insurance institute, paid for by car insurers, agreed to join the effort.
Even so, experts at the insurance institute expect the number of deaths to rise because speeds are higher.
Both vehicles were rated poor by the insurance institute and suffered average damage of more than $1,350.
Now the data of the insurance institute and the highway safety agency alike have been challenged.
The insurance institute uses ratings of poor, marginal, acceptable and good.
In 2003, major automakers agreed to work jointly on the problem, and a recent study by the insurance institute said progress was being made.
That leaves groups like the insurance institute, which uses the carrot and stick of publicity.
Recent studies by both the traffic safety administration and the insurance institute have also suggested stability control systems could save thousands of lives annually.