CNG cars contributed 17% to the total sales and 33% to the sales of the models with CNG variants. CNG’s contribution to the overall industry sales is about 8.5%. Maruti Suzuki has 9 out of 15 models with CNG options. The biggest driver of the demand is the low running cost of CNG cars at about INR1.80 /km. For petrol / diesel cars it is about INR 5.20 /km, the company said.