Tires and tired. Those will be the two main concerns for the men behind the wheel – such as Team USA driver Scott Speed – this weekend at Circuito Estoril in Portugal, the third stop on the inaugural A1 Grand Prix of Nations competition.

A regular stop on the Formula 1 circuit between 1984 and 1996, Circuito Estoril has a track layout very similar to its Iberian counterpart at Barcelona. And that means long-sweeping turns that are not only tough on tires, but very tiring for drivers.

"Every track has its unique challenges, but Circuito Estoril is one of the most difficult tracks because it is physically grueling, both for your tires and yourself as a driver," said Speed, who hopes to move the U.S. up in the standings with an impressive showing. "But it's the same for everybody. The driver who is physically up to the task and the team that is quick in the pits will win this race.

"Fortunately, we have great tires for this type of race. The surface of these slick Cooper A1 tires can become almost gel-like with the high track temperatures, and the way that they 'squash' into the track surfaces really helps with grip and cornering."

Located nearly four miles northwest of Lisbon on the northern coast of the estuary of the River Tagus, the track can be found in the hills behind the once-glamorous resort town of Estoril and the small fishing port of Cascais.

The 192-plus-mile race will include 71 laps. Drivers will attempt to break the track record for fastest lap (1:14.859) turned in by Damon Hill in 1993. Alain Prost was the first Grand Prix winner at this track, in 1984, while Jacques Villeneuve was the most recent, in 1996.