F40
F40, F.40, or F-40 may refer to:

Transportation
Aircraft
Farman F.40, a French pusher biplane reconnaissance aircraft
Hirth F-40, a German aircraft engine
F40, the NATO code for the JP-4 jet fuel

Automobiles
Beijing F40, a Chinese subcompact pickup truck
Ferrari F40, an Italian mid-engine sports car
BMW 1 Series (F40), a German subcompact hatchback
GM F40 transmission, a car gearbox

Trains
EMD F40C, an American diesel-electric locomotive
EMD F40PH, an American diesel locomotive

Watercraft
Brazilian frigate Niterói (F-40), a Niteroi-class frigate of the Brazilian Navy
HMS Jervis Bay (F40), a British armed merchant cruiser
HMS Roberts (F40), a Roberts-class monitor of the Royal Navy
HMS Sirius (F40), a Leander-class frigate of the Royal Navy
INS Talwar (F40), the lead ship of the Talwar-class frigates of the Indian Navy

Other uses
F40 (classification), a disability sport classification for athletes of short stature
F40 (full name F40T12) is a common size fluorescent lamp, at 4 foot or 1.2m