@Akbar_Khan, I've driven a 2.0D Saloon and an Altis A/T on CNG aswell as without. I must say that the performance of the Altis on petrol is superb, but fuel prices pretty much neagte the need for performance these days! Altis on CNG is very impressive too, considering its a powerful 1.8L engine. Performance of the 2.0D is decent, not impressive in the least. Takes quite a while to reach 100Kph, but low end torque is good. Performance figures just cannot be compared. The Altis whops up 100KW compared to the 53KW of the Diesel. Base price, go for the Altis CNG! Resale ofcourse, 2.0D!! Good luck bruv and do let me know of your decision, because im in a similar situtaion.