"The new car does better in the small overlap test than the TSX, which earned a marginal rating, but not as well as the TL, which earned the top rating of good," said the Institute in a statement on Tuesday.
The small overlap test replicates what happens when the front corner of a vehicle collides with another vehicle or an object such as a tree or a utility pole. The TLX earned an acceptable rating in the small overlap front test, good ratings in four other crash tests and a superior rating for front crash protection.
"In the small overlap test, the driver space was maintained reasonably well, with maximum intrusion of about 7 inches at the lower hinge pillar," the Institute said.
It added: "Measures from the dummy sensors indicated that injuries to the left lower leg would be possible, but the risk of other injuries in a crash of this severity was low."
The National Highway Traffic Safety Administration has not rated the 2015 TLX.
The 2014 BMW 3 Series sedan earned a marginal rating in the Institute's small overlap test and good in all other crash tests. The 2014 Audi A4 earned a poor rating in the small overlap test and good in all other crash tests.
The TLX is on sale now at Acura dealerships.
Edmunds says: This is a key piece of safety information for car shoppers considering the Acura TLX.