Alternate strategy: 10/14 (not recommended, but possible) Tyre choice: Qualifying/Stint 1 - Alternate (reds) Stint 2 - Primary (blacks)
*** Notes: *** With the 21S1 iRacing build we have an rebuilt IndyCar with many changes to the driving and setup styles. High speed grip is more limited and low speed grip is improved. Tyres wear significantly differently now with temperature degredation being the limiting factor rather than raw wear % that we had in the past. Differing tyre compounds allow more strategic options for the races, with the primary (black) tyre able to withstand temperature longer than the alternate tyre (reds) at the expense of raw pace. You are not required to run both compounds in a race distance but you must start the race with the tyre compound that you also qualified with. At Road America the alternate tyre struggles badly past 5-6 laps with rear grip, so the alternative strategy starting on alternate tyres is not advised unless you practice a ton with it first. Protect the rear tyres in the race!
If you have any questions, feedback or discussion, head to the Majors Garage discord where you can either @ me or post in the #indycar or #question-answer channels.