I have some advice though I have all discs on my car. Never get the insides of the wheels washed. A lot of the Braking Force is gone.
btw Please do not try something like go very fast and slam the brakes hard to see if there are marks left on the road. You are most likely to cause a very big accident and you may be dead too. 
I think the Alto comes with a 9" Brake Booster and normally that is ok.
I will never take CNG. I cannot believe it makes your brakes and engine fail. 