Maruti 800 is not available in diesel variant as it only came with a 800 cc petrol engine. You can wait for a few more days and can opt for a 800 cc diesel engine Celerio, which will be launched soon in India. It is coming with a all new motor, which is said to be the most efficient motor in an Indian car, with a mileage of 30 kmpl. Maruti 800 has been permanently discontinued due to its old technology and lesser features.