I don’t smoke, and would Never do so anywhere near gasoline.
However, I’ve had Lucky car mechanics adamantly tell me a cigarette can’t cause a gasoline fire ‘cuz it burned at a lower ignition temp point than gas.
Look at what Myth busters found:
MythBusters Special 7: Hollywood on Trial
http://mythresults.com/special7
It is possible to ignite a pool of gasoline using only a cigarette.
*Partly plausible -
A cigarette has the potential to light a pool of gasoline but just doesn’t have enough sustained heat. Gas ignites between 500 °F and 540 °F, the cigarette at its hottest was between 450 °F and 500 °F but only when it was actually being smoked. An ignition is very improbable.
In my youth, I loved to watch my neighbor light his grill. He would douse the charcoal in gasoline...wait a minute for the fumes to build...and then THROW a lit match at the grill. It would flare up in a large ball of fire.
And I'm pretty sure that just about anything that is 'on fire' will ignite gas...you throw anything burning near evaporating gas, its going to ignite.
A cigarette, however, isn't typically burning with a flame. So, it normally wouldn't ignite gas.
So, why is it a bad idea to light up near gas?
1. That lighter people use to light the cigarette...well that is certainly a flame.
2. If a 'cherry' from a cigarette falls off, it gets very red on the way down, as its descent is the same as fanning it with wind...and when it hits, small sparks fly around. I would not bet my complexion that those sparks wouldn't light gasoline.
It is also routinely possible to douse a lit cigarette IN gasoline. Although not a smoker, I have seen it done many times. I believe it has nothing to do with temperature, but with embers versus a flame.