Avtur is aviation turpentine- 99.9% pure kerosene, I used it for my kero heater at home when I was a RAAFIE, for the same reason, once its been in a tank and not used it s drained out- considered to be dirty.  I would think that it would need the additives you've described!!  Burns very cleanly with little smoke or smell but wouldn't like to hazard a guess what it's octane rating is??  Len

 
Dad's 63 Landy. Founding member of the local 4x4 club too back in the day.
I used to sit on his knee learning to drive it down a local beach.

I just started joining this forum. Most of my time went on off-road driving but I haven't tried using bikes and ATV. 

Nice one HAK, but.....
Oh oh , I can hear Betty in the background getting a bit jealous and starting to grumble  !!!!