Sesi 30 menit ini berlangsung di lintasan basah dengan hujan ringan masih terjadi di beberapa area lintasan.
Jorge Lorenzo jadi pebalap pertama yang turun ke lintasan, disusul Valentino Rossi, lalu para pebalap lainnya.
Kondisi membaik saat sesi berjalan, tetapi para pebalap masih ragu untuk berganti ban dari wet ke slick.
Pada menit-menit terakhir sesi, beberapa pebalap mencoba turun dengan ban slick, termasuk Loris Baz yang akhirnya mencatat waktu tercepat 1 menit 41,913 detik.
Para pebalap selanjutnya turun pada sesi kualifikasi, dimulai dengan kualifikasi pertama lalu kedua, untuk menentukan posisi start saat balapan Minggu (17/5/2015).
Berikut hasil sesi latihan bebas keempat GP Perancis.
1. Loris Baz FRA Athina Forward Racing (Forward Yamaha)* 1m 41.913s [Lap 11/11] 296km/h (Top Speed)
2. Alex De Angelis RSM Octo IodaRacing (ART) 1m 43.312s +1.399s [9/9] 288km/h
3. Dani Pedrosa ESP Repsol Honda Team (RC213V) 1m 43.434s +1.521s [8/9] 292km/h
4. Valentino Rossi ITA Movistar Yamaha MotoGP (YZR-M1) 1m 44.083s +2.170s [12/13] 294km/h
5. Cal Crutchlow GBR CWM LCR Honda (RC213V) 1m 44.262s +2.349s [9/10] 300km/h
6. Marc Marquez ESP Repsol Honda Team (RC213V) 1m 44.270s +2.357s [9/11] 290km/h
7. Jorge Lorenzo ESP Movistar Yamaha MotoGP (YZR-M1) 1m 44.452s +2.539s [12/12] 292km/h
8. Scott Redding GBR Estrella Galicia 0,0 Marc VDS (RC213V) 1m 44.635s +2.722s [9/9] 288km/h
9. Danilo Petrucci ITA Pramac Racing (Desmosedici GP14.1) 1m 44.692s +2.779s [10/11] 294km/h
10. Maverick Viñales ESP Team Suzuki Ecstar (GSX-RR)* 1m 45.588s +3.675s [12/13] 292km/h
11. Andrea Dovizioso ITA Ducati Team (Desmosedici GP15) 1m 46.311s +4.398s [6/7] 297km/h
12. Alvaro Bautista ESP Factory Aprilia Gresini (RS-GP) 1m 46.364s +4.451s [12/13] 288km/h
13. Marco Melandri ITA Factory Aprilia Gresini (RS-GP) 1m 46.831s +4.918s [10/11] 283km/h
14. Pol Espargaro ESP Monster Yamaha Tech 3 (YZR-M1) 1m 46.972s +5.059s [10/10] 296km/h
15. Yonny Hernandez COL Pramac Racing (Desmosedici GP14.2) 1m 47.742s +5.829s [5/6] 290km/h
16. Jack Miller AUS CWM LCR Honda (RC213V-RS)* 1m 47.818s +5.905s [6/9] 288km/h
17. Karel Abraham CZE Cardion AB Motoracing (RC213V-RS) 1m 47.905s +5.992s [10/11] 292km/h
18. Nicky Hayden USA Aspar MotoGP Team (RC213V-RS) 1m 48.434s +6.521s [5/7] 288km/h
19. Mike Di Meglio FRA Avintia Racing (Desmosedici GP14 Open) 1m 48.657s +6.744s [9/10] 290km/h
20. Stefan Bradl GER Athina Forward Racing (Forward Yamaha) 1m 48.757s +6.844s [6/9] 279km/h
21. Hector Barbera ESP Avintia Racing (Desmosedici GP14 Open) 1m 49.175s +7.262s [7/11] 284km/h
22. Aleix Espargaro ESP Team Suzuki Ecstar (GSX-RR) 1m 49.342s +7.429s [6/7] 282km/h
23. Bradley Smith GBR Monster Yamaha Tech 3 (YZR-M1) 1m 49.453s +7.540s [4/5] 294km/h
24. Eugene Laverty IRL Aspar MotoGP Team (RC213V-RS)* 1m 50.321s +8.408s [8/9] 287km/h
25. Andrea Iannone ITA Ducati Team (Desmosedici GP15) 1m 53.101s +11.188s [4/6] 275km/h
Fastest practice time:
Jorge Lorenzo SPA Yamaha 1m 32.647s (FP3)
Official Le Mans MotoGP records:
Best lap:
Marc Marquez SPA Honda 1m 32.042s (2014)
Fastest race lap:
Marc Marquez SPA Honda 1m 33.548s (2014)