Tata Tiago EV XZ +Tech Lux LR

140km a day is a fair bit of running, and we can understand why the low running cost of CNG appealed to you. But as you say, CNG has its downsides, and queuing to fill it is one of them. 

A hybrid is a good altenative but there is nothing available in your Rs 15 lakh budget. There are lots of good petrol and diesel automatics in the Rs. 15 lakh range, but the fuel cost would burn a hole in your pocket. An EV makes the most sense, and this is an opportune time to switch to one. They are the best automatics, and you will find EVs a joy to drive after dealing with the heavy clutch of your manual Maruti Ertiga. 

We assume you can install a home charger, in which case your other bugbear of filling at a fuel station is eliminated. Your fuel station is effectively at home. And with the home charging, your electricity costs are low, which in turn makes your 140km drive extremely light on the pocket. The trouble is that there are not too many EVs around the Rs 15 lakh mark, but there are some good options. 

The new Tata Punch EV is the best option, but it's a little tight in the back. However, since you drive yourself, this shouldn’t be an issue. A cheaper alternative, but not as nice to drive, is the Tata Tiago EV, a no-nonsense car with a lower range than the Punch. So, you will have to charge it every day. 

With a Rs 10 lakh budget, the Tata Tiago EV will be a good option for you. The Tiago EV is a smooth and sensible car, and its small footprint makes it adept for urban usage. 

It gets a 24kWh battery and its real-world range is around 190km, twice as much as your daily usage. However, you will have to charge it almost daily to ensure there is more than sufficient range at all times. By charging the car at your home, the running costs of this EV will be similar to or even lower than those of a bike. 

Alternatively, you could opt for a diesel Tata Altroz. It is a very fuel-efficient option, and even though the running costs will be higher than an EV, these will still be significantly lower than a similarly priced petrol car.

Unfortunately, no EV is available within a budget of Rs 7 lakh. You will have to extend your budget by at least 1-1.50 lakh to purchase the entry-level MG Comet or Tata Tiago EV. 

The MG Comet is an excellent urban runabout, due to its tiny footprint, which makes it easy to manoeuvre and park. Occasionally, it can seat four passengers in relative comfort, with the only limiting factor being access to its rear seats due to its two-door layout. The Tata Tiago EV is relatively more conventional in its approach, and it drives a bit better than the Comet. 

Also, it is the Tata Tiago EV, which will feel a bit more comfortable and confident for the occasional highway drives. Hence, if this is going to be your primary vehicle, we'd recommend the Tata Tiago EV for its well-roundedness.

 If you drive mostly in the city, you can go for the Tata Tiago EV. It fits in your budget, is generously equipped, and is built specifically for the daily city drive. The Long Range version gets a 24kWh battery paired with a 75hp electric motor, with a claimed range of 315km. 

In real-world testing, Autocar India recorded an average range of around 187km, which is adequate for everyday city use, especially if you can charge the car overnight at home. Occasional short intercity trips can also be managed with some basic planning. 

The MG Comet is a good option for a first-time driver. It is easy to drive, has a spacious cabin, despite being a two-door, and the electric powertrain is smooth and silent enough.

However, the 2-doors mean the Comet is not the most practical option in its segment, the boot is small, and the small tyres mean the ride can get choppy. If this is important to you, you could consider the Tata Tiago EV. Otherwise the Comet will do just fine.