RamYou are way out.WW2 we had themhalf gas producer and petrol...

Ram
You are way out.
WW2 we had them
half gas producer and petrol driven.
Not an expert.
But ones I saw were topped up at servo's with coke.Pull up at the servo and get a small shovel of coke and drop it in.
Bolted on the rear bumper...and pretty sure some kind of petrol mix.
Some experts will come along to this post and explain.
That's 73 years ago I saw them
regards