Every manufacturer decides whether it wants it's car to be sold as a Taxi. If it does, it approaches the State Transport Authority for approval. Once approved, the Regional Transport Offices get the notification from the STA and only then can a car be registered as a Taxi.
The reason, why you don't see Tata Nanos replacing Auto rickshaws. J&K Govt once thought of using petrol Nanos as taxis, but Tata Motors stopped them.
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Coming back to replacing Indica, I will start with the most viable diesel options first. And will limit the options to hatchbacks only, which can be legally registered as taxis.
Is there any other car which can beat Indica diesel's PRICE-COMFORT-INTERIOR SPACE- CHEAP SPARES & SERVICE AVAILABILITY combo? No.
You can only go up the price ladder and look for a replacement.
Following are the diesel hatchbacks, which can be registered as taxis.
Etios Liva. The, now default, choice of the taxi operators after the Indica. Comfortable and spacious and much much better build quality. More expensive, yes. But, the rock solid Toyota reliability makes up for it. Livas are more reliable and last longer than Indicas.
If a car breaks down, it is not earning you any money. One loses money every day, till the time it is in the garage. I have seen Livas with more than a lakh kilometres on the odo, still, no rattles, no squeaks.
Where a three year old Indica is phased out, the Liva goes on.
Comparing Indicas with Livas, the operators make up for the money lost on the procurement cost.
Indica Vista. It used to be the other most preferred option. But, ever since, the Live became available as taxi, it stopped making sense.
The other options such as the Ford Figo, Nissan Micra, Chevrolet Beat, Suzuki Ritz, Verito Vibe, fail to match what the Indica at the bottom end and the Live at the top end, provide.
The exact reason, why you see the maximum number of Indica and Livas on the road.
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Now, the CNG hatchbacks.
In a city where CNG is widely available, it is the fuel of choice for a large number of taxi operators. Cheaper to run and cheaper to buy, since CNG variants are generally cheaper than their diesel siblings.
Since the original question was about the Indica, I am not factoring in the boot space equation. Indicas are generally used for intracity transport. For luggage, a roof carrier is more than sufficient.
There is no manufacturer, other than Tata, which offers cars with factory fitted CNG kits and can be registered as taxis.
- Alto 800 CNG. No.
- Wagon R CNG. No.
- Celerio CNG. No.
- Santro Xing with Hyundai approved dealer fitted CNG kit. No.
- Tata Nano CNG. No.
- Tata Indica CNG. Yes.
You do see many Wagon R and Santro taxis, but all of them have retrofitted kits, which means they get no warranty from the manufacturer.
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I would love to see the following hatchbacks being available as taxis.
- The Datsun Go in a diesel or CNG avatar. It is spacious & cheap. With more service stations, spares, it can be the car which can beat Indica in its own game.
- The Nano CNG. It would be perfect for intracity commute or short journeys. It is spacious for four adults and gives great mileage. And did I mention, one can buy three Nanos for the price of two Indicas!? But, the Tatas do not want a Taxi image for the Nano.
- All CNG hatchbacks from Suzuki and Hyundai. Needless to say, with an excellent service backup and reliability record, they make the ideal taxis. Unfortunate (for taxi operators), that the manufacturers do not want to make the same mistake (as what Tata did with the Indica.
- Honda Brio in a diesel or CNG avatar. Honda reliability with great space and mileage, it has the qualities to replace marginally more expensive Liva.