[Resolved]  swift vxi — poor fuel efficiency

Address:

Thane, Maharashtra

i hv recently purchased MARUTI SWIFT VXI on 5 th sept 2010,from spectra motors ghatkopar mumbai,i found that the average fuel consumption is 9 km per lit, with partial AC on ,which i feel too low at K-SERIES engine.
i had first service done on 3 oct2010 at same place and in tht i mentioned complaint of poor fuel eff. they have reported checked /varified engine parameters but still i am not able to get the dDESIRED average on a contrary the av has gone down a little to 8.7 km /lit,
similarly without any operations(pressing any paddle) i get engine or say clutch ratteling noise momentery, what is the fault dont know.
spectra motors ghatkopar hv called me again for recheck , but can i know whats a probable cause fr both poor eff. and tht peculiar noise any relation ?
garde dh