The claims made either by maruti nor ARAI has shown the true mileage of Maruti Swift VDI. The actual mileage of Swift VDI is 18 in city or less, and 20 or less on highways. I am not saying this on my own but have spoken with many swift owners, and have also got reviews about it unofficially by a maruti service guy and he too agrees with the mileage figures I have told in the begining. There is a good turbo lag too, in highways and is risky and frightening sometimes while overtaking a bus or a truck.
Maruti unlike other auto manufacturers will give only 1 Year warranty and the amount of paint coats are also quite less compared to its competitions like VW, Chev, toyota etc.
But besides all this, maruti swift is a proper drivers car and will enjoy its other good attributes.!