Conor Daly was fastest overall but it was Ed Jones again setting the non-tow pace on the final day before qualifying for the Indianapolis 500 begins.
Daly set a 38.8426s (231.704mph, 372.891km/h) on his 54th lap in the #25 Andretti Autosport Honda to usurp team-mate Marco Andretti (#98 Andretti Herta w/ Marco & Curb-Agajanian Honda), who clocked his best of 38.9862s (230.851mph, 371.519km/h) on his second lap of Day 4 of practice.
Second through ninth were covered by less than a tenth of a second with the top 12 all setting a lap at an average speed exceeding 230mph, as turbos were turned up to 1.4 bar in preparation for qualifying.
Rounding out the top five were 2017 race winner Takuma Sato (#30 Rahal Letterman Lanigan Honda), Spencer Pigot (#21 Ed Carpenter Racing Chevrolet), and Ryan Hunter-Reay (#38 Andretti Autosport Honda).
Will Power (#12 Team Penske Chevrolet) was 11th, Scott Dixon (#9 Chip Ganassi Racing Honda) was 16th, and James Davison (#33 DCR w/ Byrd-Hollinger-Belardi Honda) was 23rd.
Having missed the day prior as McLaren Racing built up a spare chassis, Fernando Alonso put the #66 Chevrolet into 24th position.
In terms of non-towed laps, Jones remained the pace-setter with a 230.106mph (370.320km/h) effort in the #63 Ed Carpenter Racing Chevrolet, just ahead of Ed Carpenter himself (#20 Chevrolet) at 229.879mph (369.954km/h).
Power was fourth fastest on non-tows, Dixon eighth, Davison 20th, and Alonso 30th.
Kyle Kaiser produced the day’s major incident when he clouted the wall at Turn 3 in the #32 Juncos Racing Chevrolet, although the 22-year-old was thankfully uninjured.
“This is not what you want to be doing on the day before (#Indy500) qualifying.”
Kyle Kaiser is OK after this crash in practice, but the team faces a major setback as it tries to make the field of 33. Watch on @NBCSportsGold: https://t.co/PqVUeFoq4g#MustBeMay pic.twitter.com/esjN3F8z2V
— IndyCar on NBC (@IndyCaronNBC) May 17, 2019
Graham Rahal would later get away with a touch of the wall exiting Turn 1 in the #15 Rahal Letterman Lanigan Honda.
— NTT IndyCar Series (@IndyCar) May 17, 2019
Practice resumes tonight at 0800 local time (2200 AEST), leading into the first day of qualifying under the new-for-2019 format.
Results: Practice: Day 4
|19||19||Santino Ferrucci (R)||D/H/F||0:39.2025||229.577||369.468||30|
|20||7||Marcus Ericsson (R)||D/H/F||0:39.2137||229.512||369.364||39|
|25||88||Colton Herta (R)||D/H/F||0:39.2852||229.094||368.691||26|
|30||10||Felix Rosenqvist (R)||D/H/F||0:39.3927||228.469||367.685||64|
|32||42||Jordan King (R)||D/H/F||0:39.4658||228.046||367.004||56|
|34||31||Patricio O’Ward (R)||D/C/F||0:39.5581||227.513||366.147||38|
|35||81||Ben Hanley (R)||D/C/F||0:39.7059||226.667||364.785||81|
(C)hassis: D=Dallara | (E)ngine: C=Chevy, H=Honda | (T)yre: F=Firestone