Posted on 13 Apr 2010
Consumers should not buy the 2010 Lexus GX 460 sport utility vehicle because of a handling problem that could lead to a rollover and possibly "serious injury or death," according to Consumer Reports magazine.
A “don’t buy” warning is rare for the magazine, but there was no doubt it was necessary, said David Champion, the senior director of the Consumer Reports auto test division. The litmus test was whether the testers would want their families in the vehicle. The answer was no, he said, so “I wouldn’t want anybody else in it.”
The handling problem arises if the driver takes his foot off the gas pedal while driving quickly through a sharp turn. That causes the rear end of the vehicle to slide toward the outside of the turn, a condition known as “trailing-throttle” or “lift-throttle oversteer.” On dozens of other S.U.V.’s tested by the magazine, the vehicles’ electronic stability control system detected and quickly stopped the slide. But the stability control didn’t stop the GX 460 until it was almost sideways, Mr. Champion said.
“This is the first time we have seen it in an S.U.V. with E.S.C.” he said, referring to electronic stability control. Consumer Reports said it was “rare” for the magazine to “judge a vehicle’s performance not acceptable.” The last instance was with the 2001 Mitsubishi Montero Limited in 2001.
Lexus issued a statement saying that the automaker was “puzzled” by the magazine’s results since it conducts its own tests, and safety is a top priority. But Lexus said “we will take a very serious look at this and appreciate Consumer Reports’ bringing it to our attention.”
Mr. Champion said that the problem came to light at the magazine’s test track in East Haddam, Conn., while looking for “any nasty habits that might catch a driver out.” He explained, “We want a car to be benign.”
The particular test that concerned the magazine involves a turn that suddenly gets sharper. The driver enters at about 60 miles per hour and then, as if surprised, lifts off the gas. Ideally, the electronic stability control would stop a slide caused by that maneuver, allowing the vehicle to safely complete the turn.
Four of the magazine’s drivers tested the Lexus without being allowed to watch one another or to compare notes, Mr. Champion said. They met later and discovered each had a similar problem with the tail sliding too far. “It was like ‘whoa, what about that rear end!’ ” he said.
He added that technicians from Toyota later inspected the vehicle and found it met factory specifications. The magazine anonymously buys its test vehicles rather than borrowing them from automakers.
Mr. Champion said such a problem could happen in everyday driving. For example, a driver heading quickly through a turn — like a highway off-ramp — who finds the turn is sharper than expected would naturally lift off the gas, he said. The danger, he said, is that during such a slide tall vehicles like S.U.V.’s are easily tripped by curbs or soft ground, potentially causing a rollover.
The problem with the Lexus is that the electronic stability control doesn’t work well, Mr. Champion said. “The design is too slow to correct the slide before you are too far gone.”
In its statement Lexus complained that the magazine did not demonstrate the problem for its representatives. However, Mr. Champion said that when the officials visited the track it was raining hard, which would have made an apples-to-apples duplication impossible. But, he said, they showed the Lexus officials a video of their earlier tests.
Mr. Champion said electronic stability systems used on other Lexus and Toyota models have always worked quickly to stop slides, so the problem on the GX 460 was surprising. The new Toyota 4Runner, which uses the same basic architecture as the Lexus, was tested the same day and did not have the problem, he said.
“I think it is more a calibration issue of the electronic stability control,” Mr. Champion said.