For santro lovato is the best. there is no maintenance. I have two cng santro and recently third .
for best results like petrol type pickup, regularly clean your vehicles air cleaner either manullay or in service station. change air cleaner every 6 to 12 months if running is more than 15000 kms in a year. also get spark plugs ether cleaned or changed once in a year for best results. the problem of pickup or vibration to a greater extent is rectified by cleaning air cleaner and there is no need to visit your garage for setting as settings is not required . it is required only when spark plugs are cleaned or changed i.e once in a year.
I will advice to use petrol at least one km per week and that too only in top gear at speed above 50 - 60 kms so that when cng is not available the car will work smoothly on petrol and not jerk or otherwise fuel pump will choke up. also there is no maintainence in cng as compared to petrol in which tuning as on today cost 400 to 500 and in cng even if you change spark plugs it will cost 360 to 400 and air cleaner only rs. 125 to 150.If any body has any queries for cng for santro only please call me only on saturdays between 3 to 5 on 9223300851 . Hemal ganatra mumbai