Scott Dixon led his reigning champion Ganassi teammate Dario Franchitti in a one-two as IndyCar testing resumed at Sebring on Thursday.

The second group of 16 cars took to the track for a two-day session following Monday's and Tuesday's initial 10-car group test of the new DW12 IndyCar.

Despite issues in the morning restricting him to only a handful of laps, Dixon was immediately quick – setting a 51.9674sec lap that stood as the day's best and eclipsed the times from earlier in the week.

Franchitti topped the afternoon session, and was 0.1727sec slower.

Rubens Barrichello showed he has immediately come to grips with the IndyCar as he led the Chevrolet contingent in third for KV. Teammate EJ Viso had a trip into the tire barrier and was seventh, while Tony Kanaan struggled for pace in KV's third car and was 10th.

Mike Conway (AJ Foyt) and Takuma Sato (Rahal Letterman Lanigan) completed the top five.

Oriol Servia was fastest of the Lotus-powered drivers for Dreyer & Reinbold in 12th. Fellow Lotus runner Alex Tagliani only managed one lap due to throttle problems in his Bryan Herta Autosport car.

Former Dreyer & Reinbold driver Ana Beatriz made a surprise reappearance with Andretti Autosport, taking James Hinchcliffe's car for what is currently billed as a one-off test.

Pos  Driver              Team/Car                      Time      Gap
 1.  Scott Dixon         Ganassi DW12-Honda            51.9674s
 2.  Dario Franchitti    Ganassi DW12-Honda            52.1401s  + 0.1727s
 3.  Rubens Barrichello  KV DW12-Chevrolet             52.2228s  + 0.2554s
 4.  Mike Conway         Foyt DW12-Honda               52.2230s  + 0.2556s
 5.  Takuma Sato         Rahal DW12-Honda              52.4111s  + 0.4437s
 6.  Graham Rahal        Ganassi DW12-Honda            52.4956s  + 0.5282s
 7.  EJ Viso             KV DW12-Chevrolet             52.6317s  + 0.6643s
 8.  JR Hildebrand       Panther DW12-Chevrolet        52.6868s  + 0.7194s
 9.  Charlie Kimball     Ganassi DW12-Honda            52.9339s  + 0.9665s
10.  Tony Kanaan         KV DW12-Chevrolet             53.2012s  + 1.2338s
11.  Josef Newgarden     Fisher DW12-Honda             52.2013s  + 1.2339s
12.  Oriol Servia        Dreyer & Reinbold DW12-Lotus  53.3479s  + 1.3805s
13.  Ana Beatriz         Andretti DW12-Chevrolet       54.1478s  + 2.1804s
14.  Katherine Legge     Dragon DW12-Lotus             54.5918s  + 2.6244s
15.  Ed Carpenter        Carpenter DW12-Chevrolet      54.6490s  + 2.6816s
16.  Alex Tagliani       BHA DW12-Lotus                56.0766s  + 4.1092s