The factory Porsche 963 squad has won three of the eight races in which GTP cars have been eligible in the first season for IMSA's new cars featuring spec hybrid systems, including the last two at Road America and Indianapolis.
Tandy and Mathieu Jaminet are one of only two crews to have won more than once this season in Porsche's return to prototype racing and could have added further victories at Sebring without late contact with Filipe Albuquerque's Acura, a skid plank infraction after crossing the line first at Watkins Glen and a freak puncture at Road America.
Tandy and Jaminet, who will be joined by Porsche WEC driver Laurens Vanthoor for the 10-hour Petit Le Mans showdown at Road Atlanta, are just five points behind the championship-leading Action Express Cadillac and two points behind Wayne Taylor's Acura with the best placed of that trio likely to secure the title.
The #25 Team RLL BMW of Connor De Phillippi and Nick Yelloly is 38 points off the lead in fourth and could also win the title with a victory if any of its rivals finish third or lower.
Speaking to Autosport, Tandy said that while PPM "is the form team at the moment", he is "not totally sure about" what to expect from Road Atlanta.
"We’re coming off back-to-back wins with Road America and obviously Indy, so confidence is high," he said.
"What we do appreciate is Road Atlanta is a very different circuit and a very different race to the two we’ve done just now at Road America and Indy.
"So while we are the form team at the moment and the car has been quick at certain places, we’re still going to Atlanta with a lot of unknowns about which car, which chassis, which team is going to be quick. And obviously which car is going to last the distance and run to 10 hours flat out at the front of the field."
Tandy has won Petit Le Mans three times previously in Porsche GT machinery, including a remarkable outright victory in 2015 amid torrential rain as his 911 RSR's Michelin tyres proved superior to the Continentals used on the prototypes.
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However, the Briton says he's unclear on whether the characteristics of the 2.540-mile Georgia track will suit the characteristics of the 963.
"We’re not totally sure about Road Atlanta," he said.
"Our car seems very strong in the braking zones of heavy braking corners, which Atlanta doesn’t really have a lot of, it only really has one.
"We often seemed decent when the temperature range of the tyre is on the lower side, so for example if it’s difficult to cars to switch whichever range of tyre we’re given to use.
"Potentially it’s hot in the middle of the day in Atlanta, it could suit one car more than the other, but on the converse of that when the temperature drops towards the end of the race that could totally swing the other way.
"We have our ideas about what we might face at Atlanta and when particular cars might be strong and might struggle.
"I’m not going to give too much away, but it’s a track that is a bit more unknown to us than what we thought heading to Road America or Indianapolis for example."
