A bit late I know, but over the last 8 months using a twin burner (little) and a single burner (often) we used 10 litres of unleaded petrol in 10-12 weeks.
This was used in temperatures from -10c to +25c
I find the single burner much more efficient with fuel than the twin, I don't know why but it seems to be the same for those who commented above. You guys are using a lot of fuel for a hot country!
When we started using the twin burner more often I noticed an increase quite quickly. But having said that we were also in countries with low octane and poor quality fuel which is what I put it down to.
We carry a 10L jerry can in the trailer and fill up as and when required.
G

