Toyota said on Wednesday that it was concerned by the magazine rating, but had not experienced any similar problems in its own tests.
It offered to provide a loan car to concerned GX 460 owners until it identified a remedy.
"Our engineering teams are vigorously testing the GX using Consumer Reports' specific parameters to identify how we can make the GX's performance even better," Toyota said.
Toyota has sold about 5,400 of the Lexus GX 460 SUVs in the four months it has been on the market.
The car company has also suspended production of some Lexus models in Japan over problems with the breaking system.
Toyota has recalled more than nine million vehicles worldwide, including more than six million in the United States since late 2009, mainly for acceleration problems but also for some faulty brakes on some hybrid vehicles.
It faces a record $16.4m fine in the US for telling consumers and watchdogs about the potentially dangerous defects.
The company has been hit with at least 97 lawsuits seeking damages for injury or death linked to sudden acceleration and 138 class action lawsuits from angry customers suing to recoup losses in the resale value of Toyota vehicles following the recalls.
Toyota's US sales fell 16 per cent year-over-year in January and nine per cent in February before rising 41 per cent in March under unprecedented incentives.