one can't give kms balloon tyres will work however they work less than normal road tyres. i'v used MAXX, its not very expensive but good for the purpose i use it (sand dunes).

Anyways, i would suggest its better not to use it on roads as they could easily turnover your FJ..specially if speeded over roundabouts. most of the cruisers/patrols slipped are coz of baloon tyres. Anyways, decision is urs.

Take care.