Returning to scene of his team's first win, and the result that kick-started an eventual title charge, Alex Gurney set the fastest lap deep into second Rolex Series practice to keep the #99 GAINSCO/Bob Stallings Racing Pontiac Riley on top of the pile in Mexico.
Gurney, who claimed his first Rolex Series victory at the circuit last year with co-driver Jon Fogarty, logged a time of 1min 20.536secs with only three minutes remaining on the opening day at the 2.5-mile, 14-turn Autodromo Hermanos Rodriguez, setting the #99 up as one of the favourites to take Friday's pole position.
“I knew we would be up there," Gurney, who shrugged off the effects of a heavy cold, admitted, "We made probably six or seven good changes and kept improving it and, at the end there, it was the best it had been. We are pretty happy, but we know the other guys are not going to slack off, so I am sure it will be very close at the top. But so far, so good.
“I would imagine you will see some [1min] 19s before the end of the weekend. The track will clean up some more and, obviously, the tyres are giving us that little bit more grip, so it will keep coming around.”
Ryan Dalziel and Burt Frisselle also proved quick in the session, which saw six drivers unofficially besting last year's qualifying record of 1min 21.221secs. Dalziel, whose #2 SAMAX team recently switched to BMW engines, notched a time of 1min 20.880secs near the end of the session, while Frisselle accepted third fastest in the #47 Doran Racing Ford-Dallara which, prior to Thursday, had never been on a race track at speed.
“It's exciting for this team to be able to take a brand new car to the racetrack and put it in the top five," Frisselle said, "It doesn't get any better than that. My brother set the fastest lap earlier today and we were in the top three, so hopefully we will have a great battle on Saturday with a couple of Frisselle brothers fighting for a podium.”
Rounding out the top five were Oswaldo Negri's #60 Michael Shank Racing Ford Riley and Marc Goossens' #91 Bob Stallings/Riley-Matthews Motorsports Pontiac Riley.
GT class action saw points co-leader Spencer Pumpelly go quickest with a time of 1min 27.835secs, under last year's qualifying record, but the American had had to battle with Kelly Collins and Lawson Aschenbach for top honours throughout the session.
Collins, the 2006 race co-winner, was second in the #07 Banner Racing Pontiac GXP.R he shares with Paul Edwards, while Aschenbach – in his first Rolex Series trip to the Mexican track – was third in the #72 Autohaus Motorsports Pontiac.