We originally experienced the problem in a test that we use to evaluate what's called lift-off oversteer. In this test, as the vehicle is driven through a turn, the driver quickly lifts his foot off the accelerator pedal to see how the vehicle reacts. When we did this with our GX 460, its rear end slid out until the vehicle was almost sideways. Although the GX 460 has electronic stability control, which is designed to prevent a vehicle from sliding, the system wasn't intervening quickly enough to stop the slide. We consider this a safety risk because in a real-world situation this could cause a rear tire to strike a curb or slide off of the pavement, possibly causing the vehicle to roll over. Tall vehicles with a high center of gravity, such as the GX 460, heighten our concern. We are not aware, however, of any reports of injury related to this problem.
Lexus recently duplicated the problem on its own test track and developed a software upgrade for the vehicle's ESC system that would prevent the problem from happening. Dealers received the software fix last week and began notifying GX 460 owners to bring their vehicles in for repair.
We contacted the Lexus dealership from which we had anonymously bought the vehicle and made an appointment to have the recall work performed. The work took about an hour and a half.
Following that, we again put the SUV through our full series of emergency handling tests. This time, the ESC system intervened earlier and its rear did not slide out in the lift-off oversteer test. Instead, the vehicle understeered—or plowed—when it exceeded its limits of traction, which is a more common result and makes the vehicle more predictable and less likely to roll over. Overall, we did not experience any safety concerns with the corrected GX 460 in our handling tests.
We urge all affected GX 460 owners to have the recall work performed as soon as possible. Meanwhile, repaired GXs have gone back on sale.
With the fix, the GX 460's handling is ultimately secure but is still ponderous and ungainly, as is common with traditional body-on-frame SUVs. In addition, the vehicle rides comfortably, has a plush, quiet, interior, and provides quick acceleration, but its third-row seat is cramped. Overall, there are better choices if you're looking for a seven-passenger SUV, including the Acura MDX and Buick Enclave. To help buyers see how the GX 460 compares with competitive vehicles, we are also posting our ratings and full road test of it today (available to ConsumerReports.org subscribers).Related:
Lexus resumes sale of 2010 GX 460
Recall: Lexus to update 2010 GX 460 stability control software
Fix for Lexus GX 460 expected "shortly"
Toyota tests more SUVs to assess safety risk, suspends GX sales overseas
Q&A: Consumer Reports on the Lexus GX 460 test
Toyota stops sale of 2010 Lexus GX 460 after Consumer Reports safety alert
Don't Buy: Safety Risk--2010 Lexus GX 460