[Omkar]

Tata Altroz CNG Review

Tata Altroz CNG Pros

• A well-calibrated CNG system that’s comfortable to drive
• A CNG car with factory-backing, factory warranty & OEM standards of safety / quality
• Mature on-road behaviour, including at highway speeds despite the added weight
• 210 litres of usable boot space even with the CNG tanks
• CNG benefits like cheap running costs and lower CO2 emissions
• Looks absolutely stunning! Solid build too
• Nice interior with good quality parts & adequate space
• City friendly nature: light controls, agreeable ergonomics & good driveability (in CNG too)
• Available in the top variant, unlike other CNG models
• Enjoyable Harman 8-speaker ICE. One of the better systems in this segment
• Impressive kit (voice-assisted sunroof, wireless charger, auto headlamps & wipers, air purifier, ambient lighting...)
• 5-star NCAP safety rating is commendable

Tata Altroz CNG Cons

• Reduced power output is evident on the highway. CNG mode has lesser top-end performance
• Many Indian cities & towns don’t have CNG pumps. Queue for CNG can be long in metro cities
• Higher maintenance costs & upkeep (overall) in comparison with regular petrol variant
• Automatic transmission unavailable with the CNG kit
• Focus on CNG driveability means that the FE numbers won’t be as high as the competitors
• Instrument cluster from Tiago/Tigor CNG doesn’t feel premium
• Mature suspension does have a firm edge at low speeds (16" rim variants)
• Fire extinguisher is not easily accessible
• Some missing features (cruise control, auto-dimming IRVM, wireless Android Auto & Apple CarPlay, thinner spare tyre on top trims, split-folding rear seat...)
• All passengers need to get out of the vehicle while refilling CNG
• Tata's after-sales service quality is a hit or miss. Remains a gamble

This review has been jointly compiled with Vid6639. Thanks to him for the expert observations!

Since the Tata Altroz has already been reviewed by Team-BHP, this report will only focus on the 1.2L Petrol CNG model. For easy reference, here are direct links to the complete Altroz road-tests:

The Full Review

Altroz 1.5L Diesel

Altroz 1.2L Turbo-Petrol

Altroz 1.2L DCA Petrol

Introduction

CNG cars have always been aimed towards the fleet market, but given the rise in petrol and diesel prices, alternative fuels are becoming more and more popular. We saw Tata introduce the CNG variants of the Tiago and Tigor last year and these cars were primarily focused on regular car buyers. And it worked! The CNG variants contribute to about 40% of the Tiago and Tigor sales (petrol variants not EVs). That’s a very good response from the market and shows that the average customer is willing to buy a CNG car given that it is factory built and well-equipped.

So, Tata Motors has introduced the CNG variant of its B2-segment hatchback, the Altroz. On the surface, it may seem like just a CNG variant, but a lot of thought and effort has gone into this CNG conversion and it shows. The sequential CNG kit has been designed and patented by Tata. At the end of the day, if you have to buy a CNG vehicle, factory built is the way to go.

Tata’s timing of introducing the Altroz CNG is also pretty good considering that the cost of CNG recently fell by almost Rs. 8 / kg. If you’ve been following the rise and fall of the cost of CNG in your city, you know it’s been nothing less than a rollercoaster ride. Let’s take Mumbai as an example - CNG was available for ~ Rs. 50 / kg in mid-2021. In mid-2022, its price increased to ~ Rs. 80 / kg. In January this year, we saw prices go up to Rs. 89.50 / kg, but now, to the relief of most CNG car owners, the price has come down to Rs. 79 / kg (as of May 26, 2023). With the government focusing more on domestically produced natural gas, the price of CNG has come down (source) and is expected to stay in this range. Currently, CNG isn’t bound by GST and states levy VAT as high as 24.5% on gas. There have been talks about bringing the gas under the GST regime which is expected to further stabilize the cost of CNG (source). So, in a way, with stable fuel costs, more customers are likely to open up to the idea of owning a CNG car.

Another big hurdle with CNG cars is that the tank eats up boot space completely. Tata has solved this issue to an extent. Usually, you see a big single gas tank in the boot, but in the Altroz, Tata has gone with a twin-cylinder setup for better space utilisation. This makes a big difference as it allows you to use some boot space that otherwise wouldn’t be possible. Powering the Altroz CNG is a 1.2-litre, 3-cylinder Revotron petrol engine which makes 73 BHP and 103 Nm in CNG mode (vs 87 BHP and 115 Nm in petrol mode). The engine is mated to a 5-speed manual transmission. The Altroz CNG also gets a retuned suspension setup to balance the additional 150 kilos of weight. We’ll talk about all the changes in detail, so read on.

Tata Altroz CNG Price & Brochure

Tata is offering the Altroz iCNG in six variants: XE, XM+, XM+(S), XZ, XZ+(S) and XZ+O(S). The prices start at Rs. 7.55 lakh and go up to Rs. 10.55 lakh (ex-showroom, Delhi). You can check out the detailed price list here. The approximate price difference between the pure petrol version and the CNG variant is about ~ Rs. 1 lakh. That is on the higher side, but considering that this is a factory-fitted CNG, you get the peace of mind that a CNG kit won’t void your warranty. Moreover, this is a way better integration than any aftermarket sequential kit.

You can download the Tata Altroz iCNG brochure here - Tata Altroz iCNG Brochure.pdf

Ground Clearance

To bear the additional weight of roughly 150 Kg, Tata has retuned the suspension of the Altroz but made sure that the ground clearance remains the same. The Altroz CNG’s unladen ground clearance is rated at 165 mm.

Standard & Extended Warranty

The Altroz CNG is being offered with a 3-year or 1,00,000 km warranty. Extended warranty details haven’t been disclosed yet. As always, we recommend you opt for the maximum extended warranty for additional peace of mind.

Safety

The Altroz is known for its 5-star GNCAP safety rating. In the CNG variant, the rear boot floor has been reworked and it also gets additional reinforcements at the rear to aid safety. The top variant is equipped with safety features such as dual airbags, ISOFIX, ABS + EBD, Cornering Stability Control, reverse parking sensors, ISOFIX child seat anchors & seatbelt reminders (for driver + front passenger, both), reversing camera, automatic headlamps & wipers and voice alerts.

Apart from these, there are a few CNG-specific safety features like the use of high-quality stainless steel tubes and fittings to prevent any leaks. They’re also rust and corrosion-resistant and have been tested across temperatures and pressures. In the case of an accident, the CNG fuel is automatically cut off and the remaining gas from the tubes is released directly into the atmosphere through a special nozzle. The car also switches to petrol automatically if a leak is detected in the system.

The Altroz CNG is fitted with a micro switch inside the fuel lid. This is an additional safety feature that turns off the engine as soon as the fuel lid is opened. The switch will also not allow the engine to be cranked until the lid is closed. There’s also a fire extinguisher placed under the driver's seat.

[Omkar]

So, what's new on the outside?

Not much. There have been no design changes specifically for the CNG variant and it looks identical to the regular Altroz:


The Altroz measures 3,990 mm in length, 1,755 mm in width and 1,523 mm in height, with a wheelbase of 2,501 mm. The CNG variant has a kerb weight of 1,181 kg which is 145 kg heavier than the regular petrol variant:


Changes have been made to the suspension tune to make sure that the added weight doesn’t make a huge difference in terms of the balance:


You get auto halogen projector headlamps on the XZ, XZ+ and XZ+(O) variants. Foglamps are located high on the bumper. They have integrated LED DRLs and double up as cornering lights:


The Altroz used to get two tyre sizes for its 16" wheels. Now they’ve standardised the 185/60 R16 size for all engine variants. The base variants come with 165/80 R14 tyres:


Sunroof is now available on the XM+, XZ+ and XZ+(O) variants:


50 lakh cars milestone badge on the rear door:


"i-CNG" badge sits on the bottom right corner of the tailgate:


Unlike when the Altroz was first launched, the end can is not blackened (reference image):


Petrol tank capacity remains same at 37 litres:

[Omkar]

So, what's new on the inside?

Tata made a few changes to the interiors of the Altroz when they launched the dual-clutch automatic last year. The CNG variant carries over the same changes and a few CNG-specific additions:


Right spoke doesn't have any buttons because the CNG variant doesn't get cruise control (regular Altroz does):


One thing that will feel like a big step down is the instrument cluster. While the regular Altroz gets a part digital instrument cluster with an analogue speedometer, the CNG variant uses the Tiago / Tigor CNG’s instrument cluster. Since it had CNG-specific readings integrated, Tata decided to use the same in the Altroz as well. You get a tachometer on the left and a petrol fuel gauge on the right. In the top right corner is the CNG tank gauge. MID shows a digital speedometer, odometer, 2 trip meters, distance to empty, average fuel consumption and outside temperature. There’s no engine temperature gauge though:


This indication shows when the car is running on CNG mode:


While running in petrol mode, the MID displays instant fuel efficiency:


CNG button is neatly integrated into the cluster of buttons on the driver’s right-hand side:


CNG variant also gets leather upholstery but doesn’t get the tri-arrow detailing that we’d seen on the DCA variant. This is a simpler design and looks nice with the contrast white stitching:


This sticker on the driver-side B-pillar tells you the location of the fire extinguisher. It’s under the driver’s seat and it can be accessed from behind the seat:


A typical ABC-type fire extinguisher sits under the driver's seat. We found this placement to be odd. The reason being…


…that in order to access the fire extinguisher, the driver seat needs to be at the maximum height! For someone like me who’s 5’10” or Vid6639 who’s 6’ tall and prefers sitting low, this is a pain. The fire extinguisher is something that needs to be easily accessible in an emergency. But getting out of the car, raising the seat height to the maximum and then getting in through the rear door to reach the fire extinguisher defeats the purpose. It could’ve been placed in the passenger footwell like in the Tiago CNG. Not very comfortable for the passenger, but at least there’s that peace of mind of having a fire extinguisher handy:


Bosch telematics unit sits under the passenger seat. It records driving data for the connected car features:


The touchscreen is the same 7-inch unit as the regular Altroz. Tata should’ve taken this opportunity to introduce the bigger touchscreen that we saw in the Nexon. Since the Altroz XZ+(O) variant gets an air purifier, the AQI is displayed on the touchscreen:


New addition in the CNG variant is wireless charging which gives this notification on the touchscreen:


You now get a 5V, 3A Type-C USB charging port:


Wireless charging pad has tri-arrow detailing:


Since there are no drive modes, a blank replaces the switch behind the gear lever:


Roof console houses the switch for the sunroof:


Sunroof is decently sized and lets in enough light:


Tata cars have had voice commands and they’ve also had sunroofs. But the Altroz is the first car where you get a voice-operated sunroof. Here’s me and Vid6639 trying out a few commands in Hindi:

https://www.youtube.com/watch?v=453m0kYqLmU

Passenger side sun visor also has the sticker informing the occupants about the location of the fire extinguisher:


Basic CNG related safety instructions are pasted on the windshield:


Rear bench seat with the black leatherette upholstery:


5V USB port below the rear A/C vents:


The Altroz CNG has a boot space of 210 litres:


You can fold down the backrest of the rear seat to get more luggage space:


On the tailgate you will find this sticker that shows the location of the manual shut-off valve:


It’s on the left side, under the boot floor:


Hard plastic tank cover acts as a boot floor. It is quite sturdy and is held in place by two straps:


Underneath, you have a twin-cylinder setup. The total water capacity of these tanks is 60 litres. Tata has gone for this setup to get some usable boot space:


The regular Altroz gets a toolkit placed in a Styrofoam case. But here, you get this nice sturdy bag that holds the tools and the jack:


Next to the tanks, you have a nut that needs to be turned to…


…lower the spare wheel. Yes, the Altroz CNG is probably the only hatchback where the spare wheel is mounted underneath the car. The spare wheel is a 14-inch steel wheel shod with 165/80 section tyre:


A puncture repair kit is now offered on all Tata cars:


We’ve talked about the fit and finish issues in some Tata cars. That’s still an unresolved issue:


The Altroz still doesn't get side and curtain airbags (Maruti Baleno CNG does):

[Omkar]

Driving the Tata Altroz 1.2L CNG

The Altroz CNG is powered by a 1.2-litre, 3-cylinder Revotron petrol engine that makes 73 BHP @ 6,000 rpm and 103 Nm @ 3,300 rpm in CNG mode. That’s 14 BHP and 12 Nm lower than in petrol mode:


Before we get to the driving part, here’s a glance at what happens in a sequential CNG kit. CNG is stored at high pressure in the storage tank (around 200 bar). When the gas is to be introduced into the engine, it doesn’t have to be at such high pressure. Hence, it is sent through high-pressure lines towards a pressure regulator / reducer. This reducer brings down the pressure to usable levels and then directs the gas towards the engine through a low-pressure filter that removes the impurities and moisture.

If you’ve driven a CNG car before, you might be aware of the fact that it’s always recommended (especially on cold start) to start the car in petrol mode and switch to CNG mode after some time. That gives the engine some time to get proper lubrication and reach the proper temperature. However, in the Tata Altroz CNG, things are a little different. The car starts in CNG mode by default! Tata says that the injectors have been calibrated to ensure that there’s proper lubrication and no harm is caused to the engine over the long term. It will start in petrol mode automatically if the CNG levels are low.

Press the light clutch and turn the key to crank the engine. Start driving and you realise that the city driveability is decent. Vid6639 drove a CNG car after a while and was pleasantly surprised. If efficiency is what you are after, you can go up the gears smoothly with easy throttle inputs and you won’t find the Altroz complaining with a judder. The engine isn’t dead at low rpms. There’s enough pep on tap for city driving and you can easily keep up with the traffic and close gaps to the cars in front. The good driveability, light controls and all-round visibility make the Altroz very easy to drive in the city. Sure, there is a power deficit vs petrol, yet the Altroz’s CNG mode is extremely useable & driveable in the city.

You can switch between petrol and CNG modes by pressing the sweetly integrated ‘CNG’ button on the right side of the driver. What you will notice is the throttle response is a little dull in CNG mode, yet still at an acceptable level. An unforeseen advantage of this dulled throttle response is that it makes the drive smoother. You don’t really have to modulate the clutch and accelerator very consciously for a smooth drive. Another thing you will notice while driving in CNG mode is that the air-con still manages to cool the cabin effectively. This is a gripe in some other CNG cars where there is a considerable drop in the A/C performance in CNG mode. On a particularly hot day in Goa, the A/C managed to cool the cabin quickly.

Out on the highway, performance is mediocre and this is where the Altroz CNG's power deficit is more noticeable. As mentioned earlier, the engine isn’t dead at low revs. It starts coming into its stride at 2,000 rpm and when you cross 3,000 rpm, the motor starts pulling well. The 73 BHP in CNG mode is adequate for commuting in the middle lane. At the upper end of the rev band though, you will notice a performance deficit. It's not got much of a top-end. The overall performance is still alright for sedate, economy-oriented drivers. You can cruise at 100 km/h in 5th gear while the engine revs at ~2,750 rpm. The climb from 100 km/h to 120 km/h is a bit of a struggle though. We recommend sticking to 100 km/h on the highways. That’s where the engine is in its comfort zone. When you need to overtake, a downshift is a must to get the engine into its powerband. The unit won't get high-revving enthusiasts interested. While it revs till ~6,000 rpm, progress is very slow beyond 5,000 rpm.

Tata claims that the Altroz has better gradeability than most other CNG cars, so you don’t have to switch to petrol mode while going up an incline. We found this to be true and you can climb up a steep incline with very little to no throttle input. In fact, you can stop on an incline and get off the line pretty smoothly as well without much drama.

When it comes to shifting between CNG and petrol on the move, the action is seamless. While shifting from petrol to CNG, the system makes a "clunk" sound, but it is muted and not as loud as some other CNG cars.

The Altroz CNG uses the same TA65 gearbox (also seen in the Indica eV2) as the Tiago, Tigor, and Punch. The 5-speed manual gearbox's throws aren't long and the shifter's operation is light and pleasant to use, although it isn’t Hyundai or VW-like in slickness. There is some notchiness to it. Its gates are well-defined though and we had no trouble slotting into the gear we wanted to engage. What you will appreciate is the clutch, which is very light and has a short travel range. It is a boon in bumper-to-bumper traffic.

Noise, Vibration & Harshness (NVH)

This is a 3-cylinder engine and that’s pretty evident when you start the car. There’s cabin shake and you can feel the vibrations seeping into the cabin. Even on the move, you will always be aware that it’s a 3-cylinder engine.

While the engine's NVH is still tolerable in the city and you’ll get used to it, on the highway, it starts getting loud + coarse at high revs, especially above 4,500 rpm. In CNG mode you will hear a distinct clatter at high rpms and you will also feel some added vibrations on the steering.

Wind noise starts creeping in at 100 km/h and road and tyre noise are average.

Mileage & Fuel Economy

Tata is still waiting for official ARAI fuel efficiency numbers for the Altroz CNG. For reference, the Tiago CNG which shares the same engine has an ARAI-rated fuel efficiency of 26.49 km/kg. You can expect a number close to this for the Altroz. The Baleno CNG, which is the direct competition, has an ARAI-rated fuel efficiency of 30.6 km/kg.

The important thing to remember is that CNG fuel economy heavily depends on your driving style. Some owners have achieved the claimed economy figures (or very close numbers) of their CNG cars with sedate driving. Drive like an enthusiast and the CNG levels will drop at a faster rate.

The Altroz CNG is equipped with an NGV1 receptacle nozzle that allows for faster and safer refuelling. Notice the switch at the top? It's a micro switch that switches off the ignition as soon as the fuel lid is opened. The switch will also not allow the engine to start until the lid is closed. While filling, all occupants will have to get out of the vehicle - a safety precaution that is followed by all CNG pumps and is unavoidable. It’s fine if someone is driving alone, but a major inconvenience if you are travelling with elders. The reason why everyone has to get out is that CNG is stored at a very high pressure (~200 bar) and the smallest crack in the system can cause a major mishap, starting from inside the vehicle. To put 200 bar in perspective, 30 psi tyre pressure is equivalent to ~2 bar (so multiply that by 100):


Pressure regulator/reducer sits on the right, next to the battery:

Suspension

Ride Comfort

The Altroz is equipped with an independent McPherson strut dual-path suspension at the front and a twist beam suspension at the rear. The dual-path strut has two separate paths for energy to be transferred from the springs & dampers, allowing it to be better tuned (it's a 2-cup system). One of the advantages of getting a factory-fitted CNG kit is you don’t have to worry about suspension tuning or adding coil spring spacers at the back. The manufacturer’s R&D team takes care of everything. The Altroz’s suspension has been stiffened up to take the added kerb weight of ~150 kg.

The Altroz CNG has a mature suspension setup and is kind of European car-like in nature. It is a tad bit on the firmer side very much like the regular petrol variant Altroz. Tata's engineers have tried to make the ride quality very similar to the regular Altroz. At low speeds, the ride has a distinctly firm edge to it. While you can live with it, the ride is far from what we can call "plush". The Altroz doesn't ride as well as some competitors on bad city roads. Big potholes are prominently felt inside the cabin & bother you. Tata recommends a relatively high tyre pressure of 35 PSI which could be one of the reasons (30 - 32 PSI will definitely improve matters). Another contributor is the 16" wheel size that comes with the higher variants. Lower variants with 14” wheels and taller rubber will ride better for sure. As speeds increase, however, that mature suspension results in good ride quality. The suspension becomes compliant and on the expressway, there is no bounciness - the Altroz rides quite flat. Firmer suspension tunes also recover well from road undulations. On the highway, the Altroz handles broken roads decently and dismisses smaller potholes with aplomb. Most of the time, the suspension goes about its job silently and isn't clunky or loud.

Handling & Dynamics

Even with the added weight, the dynamics of the Altroz are very much similar to the regular car. Straight-line stability is exceptional and the Altroz drives like a "big car" on the expressway. There is no floatiness or nervousness at all. The car is well-planted with superb high-speed manners. The 185/60 R16 Goodyear Assurance tyres provide fair grip levels for an average Joe. The Altroz holds onto its line well and doesn't understeer easily. Body roll is controlled and the car never gets unnerving. But again, the Altroz CNG’s 73 BHP isn’t enough to unsettle it in corners.

Steering

The electric power steering is one of the nicer units around. That thick steering wheel is a delight to hold. It is light at city speeds (one-finger-light at parking speeds) and weighs up sufficiently as the speedometer needle climbs. The EPS isn't dead and does give you some feel of what the front wheels are up to.

Braking

We found the brakes to be progressive and doing their job as expected. They have cornering stability control too (Tata says "CSC supports / stabilizes the vehicle during partial braking in curves by reducing pressure at the required inner wheel. This helps to reduce the probability of vehicle oversteer during cornering + braking"). From high speeds, the car stops in a straight line sans any drama.

[Omkar]

Thread moved out from the Assembly Line.

[blackwasp]

Hats off to Tata for this innovative approach. I know this is an enthusiast's forum, but lets face it, at the end of the day, CNG cars are opted by many who want a lower cost of running.

Yes, its still not the ideal case, but already carmakers today are offering CNG in top-spec trims as well.

The Altroz CNG is currently the only CNG car in the market with a somewhat useable boot. The parcel tray could be removed to carry taller bags, but remember that the next CNG car with a useable boot is Ertiga CNG. Yes, the boot space is useable only with 3rd row folded down.

With lack of diesel options in the hatchback segment, I'm sure this will be a good option for cabbies as well. Deliver a good experience to customers without incurring a huge cost. Case in point, I have seen lots of Glanza / Baleno petrol taxis. Pretty sure they incur a much higher cost of operation than the Altroz CNG.

[extreme_torque]

Excellent all around city car. In our traffic infested cities you do not need much performance anyway. What caught me by surprise was the weight increase of 145kg over the petrol car. Isnt that a lot?

[Reinhard]

Thanks for the perfect review. Focused specifically on the points that were needed - and even unknown in many cases. Rating it 5 stars.

As for the car - well done TaMo. There is a sea of market leading CNG cars out there - with a light build, guarantying high fuel efficiency. If it was another half-hearted attempt (Tata is an expert of this over last 2 decades) - the Altroz CNG would have been doomed. It is not! They have invested enough research and money - into making the definitely costlier twin cylinder setup, with a visibly high quality top shield for luggage. Really usable boot space - is the USP of it. And Tata is known to do good tuning & auto-switching of their CNG in the Tiago etc already. This should be interesting.

And excellent to see a proper "top trim" car with CNG flexibility. No compromise needed on the features one gets with CNG.

Most importantly - glad to see that Tata has gone the distance to actually make significant changes to the monocoque underbody as well. Thats a big change, to put the spare wheel under the car, where otherwise would have been the pit of usual in-car donut. No half measures here also - like other car makers simply placing the spare wheel inside the boot where space permitted. Its a pleasant surprise too. Remember - spare wheel is no longer mandatory by law in such segments. TaMo could easily have dropped it altogether. But then haven't. Nice!

Not once does this CNG variant give a "half hearted attempt" vibe. That is big for me.

[Carma2017]

Has the CNG variant been tested by GNCAP?

If not, the 5 star moniker may be misleading as the 145kg weight up coupled with the newer testing norms introduced in July 2022 is a tough one to ace even for normal gasoline cars.

If yes, then it is a stupendous achievement!!

[pqr]

A dual CNG tank is quite an innovative move from Tata.



Here, Maruti charges ₹ 90,000 for a single 60-liter CNG tank (water equivalent) with negligible boot space. Baleno redeems itself with the refinement of a 4-cylinder engine over Tata’s 3-cylinder engine block and, of course, Maruti’s hallmark efficiency.



However, Tata as of now is charging ₹ 5,000 extra over Maruti’s benchmark and offers 210 L of boot space, and that’s the value the customer gets.

[aniketi]

How many KG of CNG can be filled at a time? With 2 cylinders in place now, can we assume it to be around 20 kg? If one can get 20 Kg at a time, it gets range of 450-500 kms which is pretty decent and best in industry.

Great effort by Tata.

[Hemantteen]

Originally Posted by aniketi

How many KG of CNG can be filled at a time? With 2 cylinders in place now, can we assume it to be around 20 kg? If one can get 20 Kg at a time, it gets range of 450-500 kms which is pretty decent and best in industry.

Great effort by Tata.

It's actually 60 ltr total or equivalent to 9-10 kgs of CNG (combined in both cylinders) depending on pressure which might give range of 170-180 kms approx. Instead of one big cylinder, Tata has used two small ones so as to fit them under the boot.

[self_driven]

Originally Posted by extreme_torque

What caught me by surprise was the weight increase of 145kg over the petrol car. Isnt that a lot?

Agreed. It is probably due to the use of two small cylinders. CNG tanks are quite heavy. With a single large cylinder setup, Tata could've easily saved 50 kilos if not more.

[directinjection]

Originally Posted by self_driven

Agreed. It is probably due to the use of two small cylinders. CNG tanks are quite heavy. With a single large cylinder setup, Tata could've easily saved 50 kilos if not more.

Lightweight CNG cylinders (Type 3 and type 4) made from composites have been around for many years now but aren't seen on vehicles since they cost much more.

https://www.autocarpro.in/news-natio...d-demand-79274

[svsantosh]

Originally Posted by Omkar

Underneath, you have a twin-cylinder setup. The total water capacity of these tanks is 60 litres. Tata has gone for this setup to get some usable boot space:
[url=https://www.team-bhp.com/carpics/2023-tata-altroz-cng/l/interior/2023-tata-altroz-cng-30.jpg]

Smart usage of dual smaller tanks compared to one large tank by other makers (making the boot useless). Probably the first multi CNG tank passenger car in India (commercial vehicles need to have multi, 2,4,6,8)

Originally Posted by extreme_torque

weight increase of 145kg over the petrol car. Isnt that a lot?

Sadly cannot be avoided with 2 metal tanks (rated to 300 psi, working 200psi) and associated plumbing and regulator inside engine bay.

Originally Posted by Carma2017

If not, the 5 star moniker may be misleading as the 145kg weight up coupled with the newer testing norms introduced in July 2022 is a tough one to ace even for normal gasoline cars.

Great point to ponder. Wonder how NCAP works for any CNG car?

Originally Posted by aniketi

... 2 cylinders in place now, can we assume it to be around 20 kg?

Maximum 9-12Kg, each cyl can take only 4-6kg max.

Originally Posted by self_driven

With a single large cylinder setup, Tata could've easily saved 50 kilos if not more.

But sacrificed on usable boot space. I had a Spresso CNG for a short time, I could not even keep office laptop backpack in it.

Originally Posted by directinjection

Lightweight CNG cylinders (Type 3 and type 4) made from composites have been around for many years now but aren't seen on vehicles since they cost much more.

They are lighter by 70% and made of composite material, there are few instances where they have exploded though (see on youtube). IIRC Skoda uses the fiber CNG tanks on its European CNG models.