CNG Mileage Per Kg: 1 Kg CNG Average and Cost Per KM19 December 2025

How many kilometres can a car travel on 1 kg of CNG? There is no single mileage figure applicable to every car. For a practical estimate, MIJO uses the following thumb rule:

For example, a car delivering 10 km/l on petrol may deliver approximately 15 km/kg on CNG.

This is a practical estimation rule, not a guaranteed mileage figure. Actual mileage varies with the vehicle, engine, traffic, driving style, AC use, load, tyre pressure, maintenance and CNG-system calibration.

CNG Mileage Thumb Rule

Actual Petrol Mileage	Estimated CNG Mileage	Estimated Range with Standard 60 Litre Cylinder / 8 kg CNG
8 km/l	12 km/kg	96 km
10 km/l	15 km/kg	120 km
12 km/l	18 km/kg	144 km
15 km/l	22.5 km/kg	180 km
18 km/l	27 km/kg	216 km
20 km/l	30 km/kg	240 km

For standard range calculations on this page, MIJO uses a 60 litre CNG cylinder with approximately 8 kg CNG fill.

Calculate Your CNG Mileage, Running Cost and Savings

Enter your vehicle's actual petrol mileage and monthly running. Estimated CNG mileage is calculated automatically using the 1.5× thumb rule.

Save Up to Approximately 48% on Fuel Running Cost

For the illustrative “up to” comparison on this page, MIJO uses Mumbai reference prices of ₹111.21/litre for petrol and ₹86/kg for CNG.

For a vehicle delivering 10 km/l on petrol:

• Estimated CNG mileage: 15 km/kg
• Petrol running cost: approximately ₹11.12/km
• CNG running cost: approximately ₹5.73/km
• Estimated saving: approximately ₹5.39/km
• Estimated fuel-running-cost saving: approximately 48.45%

At 1,500 km monthly running, the illustrative saving is approximately ₹8,081 per month or approximately ₹96,978 per year.

Fuel prices change and actual savings vary by vehicle and operating conditions. Use the calculator with current local prices for a personalised estimate.

Why Is CNG Mileage Measured in KM/KG?

Petrol is sold in litres, while automotive CNG is sold in kilograms. Petrol mileage is therefore normally expressed in km/l, while CNG mileage is expressed in km/kg.

The litre marking on a CNG cylinder describes its water capacity. It should not be treated as the kilograms of CNG filled at the station.

Standard 60 Litre CNG Cylinder Range

For the standard range illustration on this page, a 60 litre CNG cylinder is treated as filling approximately 8 kg CNG.

The range formula is:

Estimated range = Estimated CNG mileage × 8 kg

Because estimated CNG mileage is petrol mileage × 1.5, the standard range can also be estimated as:

Standard 8 kg range = Petrol mileage × 12

Example: if the vehicle delivers 10 km/l on petrol:

10 × 1.5 × 8 = approximately 120 km

Actual fill quantity and real-world mileage can vary, so actual range can differ from the estimate.

How Much CNG Is Required for 100 KM?

Use:

CNG required for 100 km = 100 ÷ CNG mileage in km/kg

Petrol Mileage	Estimated CNG Mileage	Estimated CNG Required for 100 km
8 km/l	12 km/kg	8.33 kg
10 km/l	15 km/kg	6.67 kg
12 km/l	18 km/kg	5.56 kg
15 km/l	22.5 km/kg	4.44 kg
18 km/l	27 km/kg	3.70 kg
20 km/l	30 km/kg	3.33 kg

How to Calculate CNG Cost Per KM

CNG cost per km = CNG price per kg ÷ CNG mileage in km/kg

At ₹86/kg and 15 km/kg:

₹86 ÷ 15 = approximately ₹5.73/km

How to Calculate Petrol Cost Per KM

Petrol cost per km = Petrol price per litre ÷ petrol mileage in km/l

At ₹111.21/litre and 10 km/l:

₹111.21 ÷ 10 = approximately ₹11.12/km

How to Calculate Monthly CNG Savings

Saving per km = Petrol cost per km − CNG cost per km

Monthly saving = Saving per km × monthly distance

For the Mumbai illustration:

₹5.39 × 1,500 km = approximately ₹8,081/month

How to Calculate CNG Kit Payback

Indicative payback months = Complete fitment cost ÷ estimated monthly saving

At a ₹50,000 fitment cost and approximately ₹8,081 monthly saving:

₹50,000 ÷ ₹8,081 = approximately 6.2 months

This is an indicative calculation, not a guaranteed payback commitment.

For current indicative fitment-price ranges, see CNG Kit Price in India.

What Affects Actual CNG Mileage?

• Vehicle and engine: Vehicle weight, engine capacity and overall condition affect fuel consumption.
• Traffic: Idling and stop-go traffic can reduce mileage.
• Driving style: Hard acceleration and unnecessary high RPM increase fuel consumption.
• AC use: Air-conditioner operation adds engine load.
• Passenger and luggage load: Additional load can reduce mileage.
• Tyre pressure: Incorrect tyre pressure increases rolling resistance.
• Maintenance: Ignition condition, filters and general engine health affect efficiency.
• CNG system and calibration: The system must be suitable for the vehicle and correctly installed and calibrated.
• City versus highway driving: Traffic, speed and idling conditions differ.

How to Improve CNG Mileage

• Keep the vehicle properly maintained.
• Maintain recommended tyre pressure.
• Avoid unnecessary hard acceleration.
• Avoid excessive engine RPM.
• Service CNG filters and system components at the recommended intervals.
• Ensure that the CNG system is correctly calibrated.
• Diagnose warning lights or driveability problems instead of repeatedly clearing them.
• Use a CNG system suitable for the exact vehicle and engine application.

Mileage should never be pursued by compromising correct engine operation, driveability or safety.

Conventional, Sequential and Direct Injection CNG

MIJO groups passenger-car CNG conversion systems into three principal categories:

Conventional CNG

Generally used for compatible vehicles suitable for a conventional gas-control system.

Sequential CNG

Used for compatible vehicles requiring electronically controlled sequential gas injection. Compatible MPI, BS6 and OBD-based applications remain within the Sequential CNG category.

Direct Injection CNG

Direct Injection applications require a specialised CNG system, vehicle-specific compatibility verification, suitable ECU and component configuration, correct installation and vehicle-specific calibration.

Not every Direct Injection or turbocharged vehicle should automatically be considered eligible. The exact vehicle and engine application must be verified before fitment.

Explore MIJO Four-Wheeler CNG systems or visit the Direct Injection CNG page.

Frequently Asked Questions

How many kilometres does 1 kg CNG give?

For a practical estimate, multiply the vehicle's actual petrol mileage by 1.5. A car delivering 10 km/l on petrol may therefore deliver approximately 15 km/kg on CNG.

What is the average CNG mileage per kg?

There is no single figure for every car. The 1.5× petrol-mileage rule provides a practical estimate.

How much CNG is required for 100 km?

Divide 100 by the vehicle's CNG mileage. At 15 km/kg, approximately 6.67 kg is required.

How much does it cost to drive 1 km on CNG?

Divide the CNG price per kg by CNG mileage. At ₹86/kg and 15 km/kg, the illustrative cost is approximately ₹5.73/km.

What range can I expect from a standard 60 litre CNG cylinder?

Using the standard calculation of approximately 8 kg CNG fill, a vehicle estimated at 15 km/kg has an estimated range of approximately 120 km.

Does AC affect CNG mileage?

AC operation adds engine load and can affect mileage. The actual difference varies by vehicle and operating conditions.

Why is my CNG mileage lower than expected?

Traffic, driving style, load, tyre pressure, maintenance condition and CNG-system calibration can all affect actual mileage.

How much can I save with CNG?

Using the stated Mumbai illustration and the 1.5× mileage thumb rule, the estimated fuel-running-cost saving is approximately 48%. Actual savings vary according to fuel prices and real-world mileage.

Is the payback period guaranteed?

No. Payback depends on actual mileage, monthly running, fuel prices and fitment cost.

Calculate Your Savings Before Choosing a CNG System

Use the calculator with current local fuel prices, your vehicle's actual petrol mileage, monthly running and expected fitment cost.

Get a vehicle-specific dealer fitment quotation from MIJO