Tata Aeris Petrol vs CNG 2026: Mileage, Boot, Power and Running Cost
The Tata Aeris gives you the same compact sedan with two fuels. Petrol is cheaper to buy. CNG is cheaper to run, and it asks for about ₹1 lakh more on the same trim. That gap is the whole decision.
Launch reports do not include a certified ARAI mileage sticker for the Aeris. Tata’s Anand Kulkarni told car&bike, as reported by CNBC-TV18, that real-world petrol use should be around 16 kmpl. There is no matching official CNG figure in those reports. This guide uses the published price card and engine numbers, then shows how to do the payback maths with your own pump prices.
Trim prices are in the variant guide. The wider car is in the launch guide.
Same car, two outputs#
Both versions use the 1.2-litre three-cylinder Revotron, with a five-speed manual or a five-speed AMT. Smart is manual only.
| Petrol | CNG | |
|---|---|---|
| Power | 86 PS | 75.5 PS |
| Torque | 113 Nm | 96.5 Nm |
| Tank | 35 litres petrol | Twin cylinder, 70-litre water capacity |
| Extra over the same trim | — | About ₹1.00 lakh |
| AMT extra over manual | About ₹0.55 lakh | About ₹0.55 lakh |
CNG gives up roughly 10 PS and 16 Nm. Around town with one or two people that is easy to live with. With four adults and a climb, the gas car is the slower one. The AMT on both fuels is an automated manual, so it pauses between gears. It is not the Honda Amaze’s CVT.
What CNG costs on the price list#
Introductory ex-showroom, in ₹ lakh:
| Trim | Petrol MT | CNG MT | Petrol AMT | CNG AMT |
|---|---|---|---|---|
| Smart | 5.29 | 6.29 | — | — |
| Pure | 6.14 | 7.14 | 6.69 | 7.69 |
| Pure+ | 6.74 | 7.74 | 7.29 | 8.29 |
| Creative | 7.49 | 8.49 | 8.04 | 9.04 |
| Accomplished | 8.19 | 9.19 | 8.74 | 9.74 |
Two traps sit in that table.
First, people compare Smart petrol at ₹5.29 lakh with Accomplished CNG AMT at ₹9.74 lakh and decide “CNG is too expensive.” That is a ₹4.45 lakh jump of fuel, gearbox, and trim together. The fuel step alone is ₹1 lakh.
Second, a city buyer who wants no clutch should compare Pure petrol AMT at ₹6.69 lakh with Pure CNG AMT at ₹7.69 lakh. That is the fair pair.
CNG cars are reported on 14-inch wheels even on upper trims. Higher petrol cars get 15-inch dual-tone alloys. If the alloys are part of why you wanted Creative or Accomplished, the petrol car is the one that has them.
Boot space before you talk about fuel bills#
Petrol boot space is 419 litres. That is not in dispute in the launch coverage.
CNG is. Autocar Professional says Tata’s twin-cylinder layout preserves 419 litres, and Tata has shown a render of that boot. Autocar India and CNBC-TV18 still expect about 227 litres, carried over from the Tigor CNG. Even 227 litres would be the largest CNG trunk among the Dzire, Amaze, and Aura, but it is a different car from a 419-litre tourer.
Open the boot of a CNG display car. If the floor is high and the space is shallow, price the car as a city commuter. If it really matches the petrol hold, the Aeris CNG is unusually practical for this class.
CNG safety hardware is specific: leak detection, one electronic control unit, direct start on gas, and extra rear structure around the cylinders. You do not get those parts on the petrol car because you do not need them.
A payback sum you can redo at the pump#
Do not treat the numbers below as Tata’s claim. They are a worksheet. Swap in today’s petrol price per litre, today’s CNG price per kg, and the mileage you believe after a test drive.
Assumptions for this example only:
- Petrol at ₹105 a litre, and 16 km per litre
- CNG at ₹85 a kg, and 22 km per kg
- Same trim, so the CNG car costs ₹1,00,000 more
- 15,000 km a year
Cost per kilometre:
- Petrol: 105 ÷ 16 = ₹6.56 per km
- CNG: 85 ÷ 22 = ₹3.86 per km
- Saving: about ₹2.70 per km
At 15,000 km a year, that is about ₹40,500 a year. The ₹1 lakh premium comes back in roughly two and a half years. At 8,000 km a year, the same saving takes about four and a half years. At 25,000 km a year, it takes about a year and a half.
Change 22 km/kg to 18 km/kg and the saving shrinks. Change CNG from ₹85 to ₹95 a kg and it shrinks again. The method stays the same:
- Rupees per km = fuel price ÷ km per unit
- Annual saving = difference per km × yearly kilometres
- Payback years = ₹1,00,000 ÷ annual saving
Add two costs the worksheet ignores. Insurance can be slightly higher on the dearer CNG car. A long highway trip can also force a petrol top-up where gas pumps are sparse. Confirm how much petrol the CNG car still carries, and what that backup is for, before you treat it as a touring tank.
Which fuel for which driver#
Buy petrol if:
- The car does school runs and weekend errands, not a long commute
- You want 15-inch alloys on a higher trim
- You care more about the 86 PS response than about the fuel bill
- You cannot see a CNG boot you are happy with
- You will sell the car in under three years and may not finish the payback
Buy CNG if:
- One driver does a heavy daily distance and can refill gas without a large detour
- You are comparing the same trim, not a base petrol with a loaded gas car
- The boot you saw still holds the bags you actually carry
- You plan to keep the car long enough for the ₹1 lakh to come back
Buy the CNG AMT if traffic is the reason you wanted an automatic and the kilometres are still high enough. Pure CNG AMT at ₹7.69 lakh is the sensible spot. Accomplished CNG AMT at ₹9.74 lakh only makes sense when you already wanted the top kit.
Buy the CNG manual if you want the fuel saving without the extra ₹55,000. Smart CNG at ₹6.29 lakh is the cheapest factory-gas Aeris on the published card. One report said Smart has no CNG. The Autocar price tables list it. Confirm the order form.
Petrol, CNG, and the rivals#
The Dzire is still the usual pick when the only goal is a low fuel bill and a workshop in every town. The Aeris case is six airbags on the base car, a large petrol boot, and a twin-cylinder layout that may keep more trunk than a single-tank rival. Price and safety versus the Dzire, Amaze, and Aura are in the comparison. If the dealer has both fuels, drive the same crawl and the same flyover in each.
What to write on the quote#
Ask for two on-road quotes, same trim, petrol and CNG. The ex-showroom gap is ₹1 lakh. Registration is a percentage of the car’s price in many states, so the on-road gap can be wider than ₹1 lakh. Use the on-road gap in the payback sum, not the ex-showroom gap.
Also ask:
- Waiting time for that fuel and gearbox
- Boot litres for the CNG car they will deliver
- Whether 14-inch wheels are what your CNG trim actually gets
- Service interval and the CNG filter or leak-check items, as a separate line
Save both quotes. If the dealer sends a heavy scan, compress the PDF and keep the two files side by side.
FAQ#
What is the Tata Aeris mileage?#
Tata has indicated about 16 kmpl for the petrol car in real use. A certified ARAI petrol or CNG figure was not part of the launch reports used here. Judge CNG on a test drive and on your city’s gas price.
How much more is the CNG variant?#
About ₹1 lakh ex-showroom over the same trim and gearbox. The AMT is a further ₹55,000 on either fuel, from Pure upward.
Does CNG cut the boot?#
Sources disagree. One report says the twin cylinders keep 419 litres. Others expect about 227 litres. Look in the boot.
Is the CNG car slower?#
Yes, on paper and on a loaded climb. It makes 75.5 PS and 96.5 Nm against 86 PS and 113 Nm on petrol.
Which CNG variant should most people shortlist?#
Pure CNG manual if you can live with a clutch. Pure CNG AMT if you cannot. Move higher only for features you will use every week.
Bottom line#
Petrol is the right Aeris when the kilometres are modest or you want the stronger engine and the larger wheels. CNG is the right Aeris when the same trim’s ₹1 lakh premium comes back inside the years you will keep the car, and when the boot you inspected still works for your luggage.
Do the sum with your pump prices and your real annual kilometres. Then book the fuel, not the badge.