Two lawmakers from the Communist Party, which is nominally in opposition to the ruling United Russia faction but is ​usually fully supportive of the Kremlin, voiced scathing attacks on the government's handling of the issue ahead of a parliamentary election ⁠due in September.

One of them, Vyacheslav Markhayev, said people were queuing 36 hours to get just 15 litres of gasoline in the far eastern Zabaikalsky region.

So, that's just under 4 gallons.

Cars don't use that much fuel while idling, but at that point, even idling is using a substantial amount of the fuel.

https://carxplorer.com/how-much-gas-does-a-car-use-when-idling/

A modern car uses between 0.1 to 0.6 gallons of fuel per hour when idling, with the exact amount depending heavily on engine size and whether the air conditioner is running.

Even at the bottom end of the scale there, and assuming modern cars, a 36-hour queue would consume nearly all of the fuel you'd get waiting in line.

For a modern vehicle, it is almost always better to turn the engine off if you expect to be stopped for more than 30 seconds. The amount of fuel used to restart an engine is minimal and equivalent to only a few seconds of idling. This simple habit can lead to significant fuel savings.

I guess if they try to allow large gaps and don't worry about other cars cutting in the line, so that the restarts are infrequent, they can reduce that by keeping engines off as much as possible.

The fuel overhead from the queuing itself is gonna be meaningful, even aside from the human time overhead.