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CNG vs LPG vs Petrol: Full Cost Comparison for Bangladesh Cars (2026)

A detailed, number-driven comparison of CNG, auto LPG, and petrol fuel costs for Bangladeshi drivers — with real per-km cost calculations, break-even analysis, and a verdict on which fuel saves the most money.

Md. Qamrul HassanPublished 6 June 20268 min read

Review status

Published on 6 June 2026 and maintained alongside the matching calculator so article guidance and tool logic stay aligned.

Source policy

CostNest articles are written to support the related calculator and prioritise official notices, standards, and primary-source references whenever a rate or formula matters.

Use with care

This guide is designed as a practical reference. Use it for planning, then confirm official requirements or professional advice when accuracy has financial, legal, or medical consequences.

With petrol now at ৳125 per litre and CNG at ৳43 per kg, the financial case for alternative fuels in Bangladesh has never been stronger. But the raw price at the pump is only half the story — fuel economy, conversion kit costs, engine wear, and refuelling convenience all affect the real total cost of ownership. This guide breaks down every factor so you can make a genuinely informed decision about which fuel makes sense for your car and your driving pattern.

Current Fuel Prices in Bangladesh (June 2026)

Bangladesh Pump Prices — June 2026

Fuel TypePriceUnitAuthority
CNG (Compressed Natural Gas)৳43per kgRPGCL / BPC
Auto LPG৳80per litreMarket rate
Auto LPG (by weight)৳148per kgLPG density 0.54 kg/L
Octane (95)৳130per litreBPC
Petrol (Unleaded 91)৳125per litreBPC
Diesel৳109per litreBPC

Note

CNG is sold by weight (kg) because gas volume varies with temperature and pressure. LPG is sold by litre at auto LPG stations but by kg in cylinders. These prices are Bangladesh Petroleum Corporation (BPC) and RPGCL approved rates effective June 2026.

Per-km Fuel Cost Calculation

To compare fairly, we need to convert each fuel's price into cost per kilometre driven. This requires knowing each fuel's typical fuel economy for the same car — a mid-size CNG-converted sedan (e.g. Toyota Corolla or similar).

Formula
Cost per km = Fuel Price ÷ Fuel Economy

CNG example:
  Fuel economy: 18 km/kg (typical for a 1.3L–1.6L CNG sedan)
  Price: ৳43/kg
  Cost per km = 43 ÷ 18 = ৳2.39/km

Auto LPG example:
  Fuel economy: 12 km/L (LPG has lower energy density than petrol)
  Price: ৳80/L
  Cost per km = 80 ÷ 12 = ৳6.67/km

Petrol example:
  Fuel economy: 14 km/L (same car running on petrol)
  Price: ৳125/L
  Cost per km = 125 ÷ 14 = ৳8.93/km

Per-km Fuel Cost Summary (Mid-size Sedan)

FuelFuel EconomyPriceCost per kmMonthly Cost (2,000 km)
CNG18 km/kg৳43/kg৳2.39/km৳4,780
Auto LPG12 km/L৳80/L৳6.67/km৳13,333
Petrol (91)14 km/L৳125/L৳8.93/km৳17,857
Octane (95)14.5 km/L৳130/L৳8.97/km৳17,931

Break-Even: How Long to Recover the CNG Kit Cost?

A CNG conversion kit costs approximately ৳45,000–৳80,000 installed in Bangladesh (sequential injection kit, BRTA-approved cylinder). The break-even point — when savings exceed the installation cost — depends on how much you drive.

Formula
Monthly saving (CNG vs petrol):
  Petrol cost: ৳8.93/km × 2,000 km = ৳17,857
  CNG cost: ৳2.39/km × 2,000 km = ৳4,780
  Monthly saving = ৳17,857 − ৳4,780 = ৳13,077

Break-even (৳60,000 kit):
  Months to break even = ৳60,000 ÷ ৳13,077 = 4.6 months
  Annual saving after break-even: ৳13,077 × 12 = ৳1,56,924

Break-even (৳80,000 kit):
  Months to break even = ৳80,000 ÷ ৳13,077 = 6.1 months

CNG Disadvantages to Factor In

  • Range reduction: A standard 60-litre CNG cylinder holds ~13 kg of gas, giving roughly 230 km range — less than a full petrol tank. You must plan refuelling more carefully.
  • Boot space loss: The cylinder takes up significant boot space (especially in sedans). Sequential-injection kits with rear-mounted cylinders are better but still reduce luggage capacity.
  • Station availability: CNG stations are well distributed in Dhaka, Chittagong, and Sylhet but sparse in rural areas and northern divisions.
  • Engine maintenance: CNG burns hotter than petrol, requiring valve seat upgrades in older engines and slightly more frequent spark plug changes.
  • Power loss: CNG delivers 10–15% less horsepower than petrol in the same engine due to lower energy density per unit volume.
  • BRTA compliance: CNG cylinders must be tested and certified every 5 years under BRTA rules. Budget ৳3,000–৳5,000 for each re-certification.

Verdict: Which Fuel Is Right for You?

CNG vs LPG vs Petrol — Best Use Case

FuelBest ForAvoid If
CNGHigh-mileage city drivers in Dhaka/CTG, professional drivers, CNGs and auto-rickshawsYou drive mainly on highways or in rural areas without CNG stations
Auto LPGSuburban drivers, vehicles with small boots, those who want petrol-like performanceYou want the cheapest per-km cost — CNG is significantly cheaper
PetrolLow-mileage drivers (<1,000 km/month), highway drivers, new cars under warrantyYou drive more than 2,000 km/month — fuel savings easily justify conversion

Tip

Use the CostNest CNG & LPG Calculator to enter your specific car's fuel economy, your actual monthly km, and the current local prices to get a personalised break-even date and 5-year savings projection. The calculator also lets you compare all three fuels side by side with your own numbers.

Free Calculator

Use our free CNG & LPG Calculator Hub to apply these calculations to your own numbers instantly — no account needed, runs entirely in your browser.

Open CNG & LPG Calculator Hub

Editorial note

Articles on CostNest are written to help readers understand the logic behind each tool, not just produce a number. If a figure on this page affects tax filing, property registration, healthcare, import costs, or any other high-stakes decision, confirm the latest official rule or professional advice before acting.

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