Some time ago while on holiday in Australia,leaded fuels were taken off the market.However a LS fuel (lead substitute) could be bought at the pumps.While there I was taken on sightseeing trips in a weight shift microlite,and it was brought to notice that there was a possibility that a precipitate could form in fuel tanks exposed to sunlight.This precipitate could block filters,jets ,etc.and it was suggested that the typical microlite translucent fuel tanks be darkened to prevent this.Car tanks of course were all in the dark.It appears only LS fuel was affected.I dont know the situation now but found this very interesting. Some say that using 100 LL Avgas in VW engines shortens life and causes scouring .Can adding "upper cylinder" lubricants to the Avgas help ? Best Regards, Eric Evezard, South Africa
