Bourdais, who won race 2 here in 2015 and race 1 in 2016, produced a 1min17.8545sec lap to edge Chip Ganassi Racing’s Scott Dixon by a mere 0.0623sec and last year’s double-winner Graham Rahal by 0.1285sec.

Alexander Rossi, Marco Andretti, Ryan Hunter-Reay and Zach Veach were fourth, fifth, seventh and eighth quickest respectively for Andretti Autosport, their symmetry ruined by a novice.

Santino Ferrucci, subbing for Pietro Fittipaldi in the #19 Dale Coyne Racing-Honda, and with only a brief test at Putnam Park in Illinois, to his name, was one of the few drivers to get a clean lap in when the cars were release from pitlane with a minute to go following a red-flag stoppage, and he made the most of it to go to P6.

That red flag was caused by Robert Wickens visiting the Turn 7 runoff, stalling and needing a bumpstart. It wasn’t the first stoppage of the session; that had come eight minutes earlier when Rene Binder stuffed his Juncos Racing-Chevrolet into the tire barrier at the bumpy medium-speed Turn 11, thankfully without much damage.

Top Chevrolet runner was Josef Newgarden in ninth, his Team Penske teamamtes Simon Pagenaud and Will Power occupying P11 and P13. Tenth was Tony Kanaan for AJ Foyt Racing-Chevrolet.

The Honda team that appears to be struggling quite surprisingly is Schmidt Peterson Motorsports – Wickens only 15^th and James Hinchcliffe 21^st.

IndyCar, Detroit first practice

Cla	#	Driver	Laps	Time	Gap	Interval	Mph
1	18	Sébastien Bourdais	15	1'17.8545			108.664
2	9	Scott Dixon	13	1'17.9168	0.0623	0.0623	108.577
3	15	Graham Rahal	14	1'17.9830	0.1285	0.0662	108.485
4	27	Alexander Rossi	13	1'18.1504	0.2959	0.1674	108.253
5	98	Marco Andretti	13	1'18.3009	0.4464	0.1505	108.045
6	19	Santino Ferrucci	21	1'18.3117	0.4572	0.0108	108.030
7	28	Ryan Hunter-Reay	15	1'18.3366	0.4821	0.0249	107.995
8	26	Zach Veach	17	1'18.3529	0.4984	0.0163	107.973
9	1	Josef Newgarden	14	1'18.3997	0.5452	0.0468	107.909
10	14	Tony Kanaan	13	1'18.4611	0.6066	0.0614	107.824
11	22	Simon Pagenaud	15	1'18.6425	0.7880	0.1814	107.575
12	30	Takuma Sato	15	1'18.6781	0.8236	0.0356	107.527
13	12	Will Power	13	1'18.9027	1.0482	0.2246	107.221
14	59	Max Chilton	17	1'18.9297	1.0752	0.0270	107.184
15	6	Robert Wickens	16	1'18.9724	1.1179	0.0427	107.126
16	23	Charlie Kimball	15	1'19.0906	1.2361	0.1182	106.966
17	20	Jordan King	17	1'19.1719	1.3174	0.0813	106.856
18	4	Matheus Leist	18	1'19.1933	1.3388	0.0214	106.827
19	21	Spencer Pigot	14	1'19.4102	1.5557	0.2169	106.535
20	10	Ed Jones	19	1'19.5470	1.6925	0.1368	106.352
21	5	James Hinchcliffe	11	1'19.6973	1.8428	0.1503	106.152
22	88	Gabby Chaves	16	1'20.2853	2.4308	0.5880	105.374
23	32	Rene Binder	16	1'21.8363	3.9818	1.5510	103.377