I have MEHRAN VX 2007.(26000 K/M) when i switch petrol to CNG, black smoke is exahausted.after 3,4 minutes it normal. car reducing oil levelit happens only if car runs a few k/m on petrol and switch to CNGwhat could be the problem
Black smoke isn't sign of weak engine...its the blue one....
if you are getting black smoke that indicates=un-burnt fuel coming out as it is.white or blue smoke are the sign of weak motor.get it properly checked.