Juz flipping thru' wanbao tis evening. It says dat some car drivers hv used CNG instead of petrol in order 2 cut costs. Now d price of CNG is $1.40/L. But oni can go 2 jurong island, mandai link or jalan buroh 2 top up d gas.
Lastly, it oso states dat if u nid 2 travel for 300km, u nids 2 spend approx $30 for CNG supply.
there was an article on newpaper last week..
saying that if u pump singapore's cng for about 25-30 bucks,
you can get it at 6 bucks at jb for same amount.. and 3/4 tank does not apply..
but i can say that cng will lower your car's performance.. ive test driven one..
http://www.sgforums.com/forums/2/topics/314873