What is the cylinder on the left side of a dirt midget car? Almost looks like a fire extinguisher but I can’t tell, it’s right by the driver?

Answer 1

Oil tank for the dry sump engine lube system

Answer 2

Look at the color!

I suspect it is an over flow tank or catch tank of some sorts.

The pictures I see show fire extinguishers inside the car and some times mounted on the roll cage.