I have purchased tata indica xeta GLS with CNG fittment (by tata) 8 months back. The vehicle gives black smoke on CNG & petrol. The vehicle is jerking and having very poor pickup on CNG/Petrol. Regularly this vehicle shows check engine error. In the span of last four months, SIX TIMES I have sent my vehicle to TATA Service centre for the same repeated problems. These mentioned problems start very next day of servicing. The CNG version of TATA motors is a totally flop version. I strongly suggest eveyone to donot opt CNG version of TATA motors. read full review »