"The result is a good basis on which to further intensify preparations of the car in the U.S. starting in September, ahead of the start of the IMSA season at Daytona in January 2023," BMW said.
The car had its initial test in the U.S. this week at Sebring International Raceway in Florida.
The car will run in the 2023 IMSA WeatherTech SportsCar Championship and is eligible for the FIA World Endurance Championship, including the 24 Hours of Le Mans. Ferrari, Cadillac, Acura and Porsche also have similar programs.
The cars will race in IMSA's GTP class. Rules specify they be rear-wheel-drive and use a standard hybrid system mated to a gasoline engine of the automakers' choice. The powertrain is capped at about 640 hp.
"The first weeks of testing with the BMW M Hybrid V8 went well," said Andreas Roos, head of BMW M Motorsport.
"We have completed a lot of kilometers, during which we uncovered the first weaknesses, which are totally normal with a new car, and have solved some of them already. Furthermore, it was important to get feedback from as many drivers as possible in order to get a good early impression of how our prototype handles. Their response has been very positive in this early stage. ... We laid a good foundation during the tests in Europe. Now we enter the next development stage in the U.S."
The company said 10 of its contracted drivers have driven the car so far.
During tests in Italy and Spain, the focus was on system checks and the first performance-related topics.
BMW said the car has been driven in hot and dry conditions, in the rain and in the dark, when its front and rear lights were seen for the first time.
"On the whole, there haven't been any fundamental issues," the company said, adding that teething troubles, normal for a new car, have been identified and will be addressed in future tests.
Both BMW M Motorsport and Bobby Rahal's Team RLL will test the car in the U.S., and the company said "a host of different drivers will be used again during these tests."