I have been driving a Smart cab KIA Carens cab on my own for 2 weeks now and below are my observations:
1.
It is not worth driving a CNG/Petrol cab is it is troublesome. You have to always top-up both CNG and Petrol. To top that off, 1 tank of CNG is not enough for 1 day's trip. Usually have to top-up at least twice a day. And only 2 places to top-up: Mandai ($1.28/litre)and Serangoon North ($1.34/litre). Operation time is only from 8am to 8pm. Thus, very inconvenient.
2.
It cost more money, naturally.
3.
CNG engine has only 75% of it petrol power. You can tell the difference when it comes to climbing up the ECP from Suntec city.
As for the car itself, it was surprising smooth and road handling is great. Very easy and comfortable to drive. The car seats are just at the right level where you literally put your bottom in and sit down. My only problem with it is the turning radius is relatively small for small a family size car. Many customers like the car and the comfort level it provides.
Sometimes there's some quick and small vibrating jerks but that's about all. Fuel consumption is not bad for CNG. At the same time it is also slowly but surely sipping away the petrol. Thus, I pump 92 and only on half tank all the time. As for the space wise, I personally think that is it larger than a saloon car booth.
Both Amk1777 and MoshiMoshi are right. It is time consumming and troublesome.
