"It's the first time I have driven an Indycar, as well as my first run at Texas Motor Speedway, so before we got started I really didn't know what to expect." Mann said, "But it didn't take much time for me to get comfortable in the car and up to speed.
"Overall I'm not only pleased, but excited by how the test went," said the 27-year-old Briton.
Also out testing at Texas were Simona de Silvestro (for HVM) and JR Hildebrand (with Panther Racing.)
Murray/Dixon to swap cars for the day
Scott Dixon is to trade in his open-wheel Dallara for a NASCAR Car of Tomorrow - but only for a cross-series promotion next week on March 16.
Dixon will trade cars with his Ganassi stablemate Jamie McMurray for a day, with Dixon trying out the #1 Chevrolet Impala at Talladega and McMurray getting to sample the IndyCar at Barber Motorsports Park
"Talladega? This is going to be a pretty cool experience. It's not every day someone gives you the keys to a stock car at one of the biggest tracks on the planet!" said Dixon, adding that he was just as excited to see what McMurry would do in the IndyCar. "I know he's been looking forward to getting in an IZOD IndyCar Series car for quite some time. [He's] even downloaded some of my in-car camera laps from Barber Motorsports Park – so this should be fun!"
The exchange could be seen in a new light given the $5m Vegas challenge for non-IndyCar drivers to come and see if they can win the season finale. Lewis Hamilton's previously announced swap of his McLaren with Tony Stewart's Chevrolet at Watkins Glen in the summer is less likely to see the F1 star at Vegas, however, as the Korean Grand Prix takes place the same day.
Sam Schmidt signs up Esteban Guerrieri for Indy Lights
Esteban Guerrieri is to leave the Formula Renault 3.5 series in which he was a title contender in 2010 - ultimately finishing in 3rd place in the championship - in favour of a shot at the Firestone Indy Lights title with Sam Schmidt Motorsports.
"Coming to race in the US is a big change of direction in my racing career," said the 26-year-old Argentinian.