The new LMP1 version of the HPD ARX-01e made its track debut in private testing at Sebring yesterday.
The car is an upgraded version of the LMP2-spec HPD that Highcroft took to last year's American Le Mans Series title, and features new aerodynamics and suspension as well as the power increase required for the top class.
It completed 33 laps at Sebring yesterday in the hands of David Brabham and Marino Franchitti, who will share the car with fellow team regular Simon Pagenaud in next weekend's Sebring 12 Hours.
"Today was all about systems checks, making sure nothing was rubbing or leaking and I have to congratulate the guys because we had very little go wrong today and it is a great start for the week coming up," said Brabham.
"The Highcroft boys have worked very hard to get the car here. Obviously we would have liked to been testing before Christmas but it wasn't to be.
"Everything has been a bit of a rush but the Highcroft team as usual have just done a phenomenal job."
The car was running with Le Mans downforce levels, and Franchitti said the straightline performance gain was obvious even in the shakedown.
"The car is very slippery and we have a lot more power so we have a much better straightline speed performance than what we were used to," he said.
"Last year you would accelerate along the straight and hit a virtual wall, but this year the car seems to be accelerating all the way to the end."