For this, we would suggest you have a word with the nearest service center as they will be the better person to assist you with the possibilities. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Service centre.
Though all the colors have the same price. But it would be better if you can once confirm or walk into the nearest dealership as they will be the better person to assist you. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Car Showrooms.
Maruti Eeco returns a certified mileage of 16.11 kmpl, if you are driving with AC on then mileage can drop to 2-3 points. However, the actual mileage totally depends on several factors like driving conditions, road conditions, tyre pressure, etc. In order to improve the mileage, we would suggest you drive slower. Driving fast can reduce your fuel efficiency by up to 33% if you are traveling above 60 mph. It is best to change gears appropriately and match the gear and the RPM carefully.
For the CSD availability, we would suggest you have a word with the CSD staff or walk into the nearest dealership as they will be the better person to assist you because it depends on their stock book. You can click on the following link to see the details of the nearest dealership and selecting your city accordingly - Car Showrooms.