The Jerry Can is a red 2.5 gallon petrol can that thethreeprotagonists and the Online Player are able to pour out, creating pools and trails of fuel. The petrol fuel can be ignited to engulf nearby objects including cars and NPCs. A trail can be ignited in many different ways, including shooting it and burning out with a car on the gas trail.
Inscriptions on the jerry can are "Kraftstoff 20L Feueugefährlisch 1939", German for "Flammable fuel, 20L, 1939". Historically, jerry cans were first used during the Blitzkrieg at the beginning of WWII, to refuel Panzers quickly. However this jerry can may simply reuse the design of an original one, since it holds 10 liters (2.5 gallons) instead of 20 as inscribed.
Shooting a dropped jerry can makes it explode if it's not empty. In GTA Online, this explosion pushes players in passive mode, while any other explosive weapon doesn't.
Being set on fire while holding the Jerry Can will make it explode.
In the beta version of the game, the Jerry Can had a greenish-gray (possibly camo) color (as seen in the screenshot below).
This version of the Jerry Can obviously has German origin. However, the design is similar to the American version (which is almost a direct copy of the original German version)
The "Jerry" Can is so named because the term "Jerry" is a derisive slang for a German Soldier coined by the American GI's during WW II. So it litterally means "German Can". American first encountered the cans during the N. Africa campign. Since the cans are much better than the obsolete American counterparts, the Americans quickly adapted and eventually produced their own versions.
The Jerry Can can't refill cars with gasoline.
Although Trevor is constantly seen in artworks holding a silver Zippo-styled lighter (along with the Jerry Can) in a pose implying the use of it to ignite the gasoline from the can, the player still has to use other methods to ignite the gas in the actual game.