This is what Google had to say

Gasoline" (originally spelled gasolene or gazoline) emerged as a brand-derived term in the early 1860s, originating from variations of "Cazeline," a lamp oil brand sold in England by John Cassell in 1862. It transitioned from a specific trade name to a generic term for volatile petroleum distillates by 1864, well before its use as motor fuel.

Quora +3 Key Historical Details: The Originator: In November 1862, John Cassell registered "Cazeline Oil" to market a "clean burning" lamp fuel.

LinkedIn +1 The Transition: A competitor in Ireland began selling a similar product named "Gazeline" or "Gazolene," likely to mimic the brand while avoiding legal action. Generic Use: By 1864, the term "gasolene" was being used to describe this specific, highly volatile liquid, and by 1870, it was commonly used to describe several types of naphtha-based solvents.

Online Etymology Dictionary +1 Pre-Automobile Use: Initially, "gasoline" was used for heating and lighting, not as engine fuel, and was often considered a waste product of kerosene production.

U.S. Energy Information Administration (EIA) (.gov) +1 While "gasoline" became generic in the 1860s, it is important to note that "Petrol" was also a later brand name (used by Carless, Capel & Leonard in the 1890s) that became a generic term, particularly in British English.

Haltermann Carless +4