Hi Mr. Asharaf,
This is in regards to your query posted on the website CarDekho.com, we would like to inform you that Maruti Ritz comes in both Diesel and Petrol variants. Maruti Ritz Petrol gives mileage of 14.5 km/l in city conditions and 18.0 km/l on highways. The Diesel Variants of Maruti Ritz gives mileage of 17.7 in city condtions and 21.1 on highways.
Maruti has a good and vast service network and there will be no problem of maintenance and replacement of parts at later stage but the resale value of the car might decrease as the company has decided to discontinue the vehicle. Despite this, there will never be any shortage of parts as manufacturers make parts for next 10 years. Also, as Ritz share a good number of parts with its sibling Swift there will be no shortage whatsoever. If you would like to consider, the Indian auto market has many other offerings in the same segment such as Tata Bolt, Nissan Micra, Ford Figo, Honda Brio and Grand i10, Maruti Swift, Chevrolet Sail hatchback.