Class leaders at the four-hour mark in the 55th Rolex 24 at Daytona are Max Angelelli (P), Dirk Mueller (GTLM), Sean Rayhall (PC) and Matteo Cressoni (GTD).

The third full-course caution flew following contact between John Falb and Matt McMurry at the Bus Stop, with McMurry collected and his Park Place Motorsports Porsche 911 GT3 R finding the tire barriers. McMurry was OK while Falb brought his car into the pits, and was assessed a penalty by IMSA for the contact.

Both Cadillacs from Action Express Racing had minor interruptions with the No. 31 car going behind the wall for barely a minute, if that, and the No. 5 car having the engine cover taken off. Despite the scares, neither one lost significant time.

It’s cold, and it’s now dark. Per Continental Tire with just over 20 hours remaining, before the end of the four-hour mark, temperatures were 51 degrees ambient and 67 on track. Those both figure to go down into the night hours.

With the No. 73 car retired, the list of official retirements is this:

  • No. 14 3GT Racing Lexus RC F GT3 (contact)
  • No. 24 BMW Team RLL BMW M6 GTLM (mechanical)
  • No. 59 Manthey Racing Porsche 911 GT3 R (mechanical)
  • No. 73 Park Place Motorsports Porsche 911 GT3 R (contact)

Cars that have been delayed significantly include this group:

  • No. 16 Change Racing Lamborghini Huracán GT3 (contact)
  • No. 51 Spirit of Race Ferrari 488 GT3 (unknown)
  • No. 52 PR1/Mathiasen Motorsports Ligier JS P217 Gibson (electrical)
  • No. 98 Aston Martin V12 Vantage GT3 (mechanical)

At Hour 4, 43 of the 55 starters are within 13 laps overall.

INDYCAR/Mazda Road to Indy/noteworthy open-wheel driver update. Tony Kanaan has driven the No. 69 Ford Chip Ganassi Racing Ford GT and run in the top three or four of his stint. He took over from Andy Priaulx and has handed off to Harry Tincknell. Grand marshal Dario Franchitti poked fun at Kanaan’s lack of laps prior to this stint:

https://twitter.com/dariofranchitti/status/825469493501636608

While Kanaan’s been in, Scott Dixon and Sebastien Bourdais have not been in their designated Fords. Ryan Briscoe, a name well familar to the open-wheel world, has been in for a while in the No. 67 Ford.

Spencer Pigot has been first of the two IndyCar drivers at Mazda in, but his progress has been delayed following a three-minute, 18-second penalty assessed in the fourth hour for an improper wave by. The No. 55 Mazda was also assessed a mechanical black flag. James Hinchcliffe has not yet been in the No. 70 Mazda.

Neither Ryan Hunter-Reay nor Graham Rahal has been in the Acura NSX GT3s yet. The tall IndyCar aces figured to be slotted third or fourth in their rotations after the Michael Shank Racing team ran through its six full-time sports car drivers.

Conor Daly hasn’t been in at Starworks’ No. 88 Oreca FLM09 but his friend Sean Rayhall has, and has helped steer that car to the lead.

Another driver with MRTI experience, Pato O’Ward, led during his first stint in the No. 38 Performance Tech Motorsports entry. O’Ward’s in a car he shares with James French, Nick Boulle and Kyle Masson.

Most of the Lexus contingent have open-wheel backgrounds. With Pruett’s No. 14 car out, that denies Sage Karam, Ian James and Gustavo Menezes a chance to race.

Austin Cindric did well to bring the No. 15 Lexus up from 20th to seventh in his stint, in a car he shares with Jack Hawksworth, Robert Alon and Dominik Farnbacher.

RC Enerson has not yet been in the PR1/Mathiasen car, as he’ll take the wheel fourth after past stints from Tom Kimber-Smith, Jose Gutierrez and Mike Guasch.

Hourly results are posted at results.imsa.com.