Some of those arent necessarily permanent numbers, instead allocated specifically to teams for FP, tests and replacements. Such numbers that I am aware of are:
#15 - Red Bull (Sainz - 2014 Abu Dhabi test, Buemi - 2014 Barcelona test) - Not seen #16 used!!
#23 - Mercedes (Wehrlein - 2015 Barcelona test)
#24 - Mercedes (Wehrlein - 2015 Spielburg & 2014 Abu Dhabi test)
#29 - Ferrari (Marciello - 2015 Barcelona test, Fuoco - 2015 Speilburg test)
#30 - Lotus (Palmer - various 2015 FP and Barcelona & Spielburg Test, Pic - various 2014 FP and tests)
#31 - Red Bull (Gasly - 2015 Barcelona & Spielburg tests) EDIT:
Also used by Buemi and da Costa in demonstration events, and maybe a test Actaully these are from 2013!
#32 - McLaren (Vandoorne - 2014 Abu Dhabi & Silverstone & Barcelona Test)
#33 - McLaren (Turvey - 2015 Barcelona test) - HOW?! #33 is Verstappens
#34 - Force India (Yelloly - 2015 Barcelona test, Wehrlein - 2015 Spielburg Test, Ocon - 2015 Spielburg Test, Goddard - 2014 Abu Dhabi Test, Juncadella - various 2014 FP, plus more drivers!!!)
#36 - Sauber (Marciello - 2015 Barcelona test, van der Garde - various 2014 FP)
#37 - Sauber (Sirotkin - 2014 Russia FP, Fong - 2014 Abu Dhabi FP)
#38 - Toro Rosso (Verstappen - various 2014 FP) [Gasly and Wittmann drove unnumbered in 2015 Barcleona and Spielburg Tests) - still in use?!
#40 - Williams (Lynn - 2015 Barcelona test, Nasr - various 2014 FP and tests)
#41 - Williams (Wolff - 2015 Spielburg test and various 2014 & 2015 FP)
#42 - Manor (Leimer - 2015 Hungary FP, Rossi - Canada & Belgium FP plus Belgium and Russia GP [withdrawn])
#47 - McLaren (Vandoorne - 2015 Spielburg test)
Former numbers(?) -
#28 - Ferrari (Marciello - 2014 Abi Dhabi Test, de la Rosa - 2014 Silverston test) - Transferred to Stevens (so why Rossi couldnt get #16, which hasnt even been used!?!?)
#31 - Lotus (Ocon - 2014 Abu Dhabi FP and Test) - Transferred to Red Bull
#33 - Lotus (Lynn - 2014 Abu Dhabi Test) - Transferred to Verstappen (though McLaren used in 2015 Barcelona test for Turvey)
#45 - Caterham (Lotterer - 2015 Belgium GP, plus Rossi and Merhi for FP)
#46 - Caterham (Stevens - 2015 Abu Dhabi GP, plus Frijns in various FP and tests)
2015 Barcelona test - https://www.formula1...-barcelona.html
2015 Spielburg test - https://www.formula1...in-austria.html
For 2014, use google using the format "[Driver] [year] [circuit]" and suitable pics should appear.
Until a driver competes in a GP with a number different to a teams allocated number, it shouldnt be assumed that any number he/she drives with is his/her permanent number.
Edited by fridge46, 18 September 2015 - 12:29.