hmm Gangsta, dekho my presumption was as follows:
a. If the mods are just to get a kick once in a while, that is enough by switching back
b. If someone was to do 80-100km in a day, then yeh delhi traffic vaat maar dega, or you'd have a driver - either case same funda as above esp since i'm a firm believer in keeping things stock with such huge driving.
but i understand where you're coming from - and am glued. Have been using CNG since 2000-01 and both our cars are CNG, so I completely vouch for the cost savings