There will be always control of government on Diesel Prices, as it is directly related to inflation.
About Petrol govt already almost not controling it, so petrol prices depends directly on international crude prices.
Petrol CAR: useful only when you are usage is very less. But still some people prefer Petrol Car because of power, less initial cost. But found most of people regret there decision after some time.
Diesel Car: Engine noise, initial higher cost, less power compared to petrol Engine is major issues with Diesel car, very limited options for many of us.
There is always waiting period for diesel car, but try to negotiate with dealer, they will try to make avaliable it for you as soon as immediately.
Once you Finalized car, alway visit more than one showroom and try to negotiate to get more discount.
If you like to travel, Dont want to think always about how much money you need for travel please go ahead with Diesel Car!
-Vijay