What Is CBG? Know About Its Production, Engine Performance, Prices and Future in India

CBG does not eliminate routine engine maintenance. Vehicles must still follow the manufacturer's service schedule, use the correct lubricants and undergo appropriate inspection of their fuel systems.

The main practical lesson is that gas quality and engine calibration matter more than whether the methane came from a fossil source or biological waste. A compliant gas used in a properly designed engine can work well, while poor-quality gas or an unsuitable conversion can create mechanical and safety problems.

Does CBG Increase or Reduce Engine Life?

There is no sound basis for claiming that compliant CBG automatically shortens engine life or that it always extends it. Long-term durability depends on the engine's design, the quality of the fuel, combustion calibration, maintenance and the operating conditions.

A CNG vehicle may be designed around a particular range of gas properties. If the CBG supplied meets the applicable standard, it is suitable for the intended application. Problems become more likely when fuel contains excessive contaminants, a converted engine operates with an incorrect air-fuel mixture, or high-pressure equipment is not maintained properly.

The available research is useful but has limits. Some studies compare fuel consumption and exhaust emissions over standard driving cycles, while others study combustion in laboratory engines. Their findings do not necessarily establish the lifetime durability of every modern Indian car, truck or motorcycle running on CBG.

A motorist considering a CNG vehicle should therefore focus on the manufacturer's approved fuel requirements, warranty conditions, service schedule and the quality assurance used by the gas supplier. That is more meaningful than assuming that every vehicle will experience the same engine wear simply because it uses CBG.

CBG vs CNG: What Does Research Say About Performance?

Two useful studies illustrate why CBG's performance should be assessed using actual engine tests rather than assumptions.

In a 2013 study published in Applied Energy, researchers tested a spark-ignition vehicle using methane-enriched biogas containing 93% methane and CNG containing 89.14% methane. Under the modified Indian driving cycle, the reported fuel economy was 24.11 km/kg for the enriched biogas and 24.38 km/kg for CNG. The difference was small, although the study found slightly higher carbon monoxide, hydrocarbon and nitrogen oxide emissions with the enriched biogas in that test.

A separate 2021 study in Energy tested a Euro VI-compliant, 11-litre natural-gas engine using CNG and biomethane. It reported a reduction in thermal efficiency of approximately 2% with the biomethane in its full-load test, as well as higher fuel consumption over the specified transient test cycle. The result demonstrates that gas composition and engine conditions can matter, but it should not be interpreted as a universal penalty for all CBG vehicles.

These findings are compatible with a practical conclusion: appropriately purified biomethane can be used as an automotive fuel, but identical mileage, power and emissions should not be assumed without testing the actual fuel and engine combination.

Current CBG and CNG Prices in India

CBG does not have one universal retail price across India. The price paid by a producer, the rate charged within a gas-distribution network and the price displayed at a filling station are different amounts.

For comparison, Indraprastha Gas Limited's published retail prices, effective from August 29, 2026, list CNG at ₹86.98 per kg in Delhi and ₹92.01 per kg in Gurugram. These are local CNG retail prices, not a nationwide CBG price.

The government has also announced changes to CBG procurement pricing under its newer GOBARdhan framework. Those figures must be understood separately from what motorists pay at the pump.

Will CBG Become More Expensive in the Future?

The government's new procurement benchmark is higher than the ₹1,478/MMBtu reference price described under the earlier framework. The government has stated that the move is intended to support CBG producers and improve the economics of new projects, with ₹10 per kg of affordability support to reduce the burden on consumers.

According to the government's August 2026 explanation, the ₹2,110/MMBtu benchmark is equivalent to an effective cost of approximately ₹1,895/MMBtu after the stated affordability support. This represents an increase of around 28% over the earlier ₹1,478/MMBtu reference price. It does not mean that CNG or CBG retail prices automatically rise by 28% or 43%, because those producer procurement values are not the same as the price at the dispensing station. 

A further factor is the CBG blending obligation for the city-gas sector. The government's GOBARdhan framework sets a notified trajectory of 3% for financial year 2026-27, 4% for 2027-28 and 5% from 2028-29 onwards in the CNG transport and domestic PNG segments.

That should create a stronger demand signal for CBG producers. The eventual effect on prices will depend on how quickly production expands, whether plants can operate efficiently, the cost of feedstock and transport, and how the government and gas distributors implement the procurement and affordability arrangements.

Environmental Benefits of CBG

One of CBG's main advantages is that it can replace fossil natural gas with methane produced from renewable organic material. It also offers a way to recover energy from waste that might otherwise be dumped, allowed to decompose in uncontrolled conditions or burned.

The environmental benefit depends on the entire production process. Capturing methane from manure or organic waste can avoid emissions that would otherwise enter the atmosphere. However, methane leakage during digestion, upgrading, compression, transport or vehicle use can reduce those benefits. The energy consumed by the plant and the type of feedstock also matter.

At the exhaust, CBG does not produce zero emissions. Burning methane generates carbon dioxide, and the engine can emit nitrogen oxides, carbon monoxide and unburned hydrocarbons. CBG can reduce lifecycle greenhouse gas emissions compared with fossil fuels when production is well managed, but this outcome should be assessed rather than assumed for every plant.

The International Energy Agency's 2026 India Bioenergy Market Report discusses how feedstock selection, methane leakage, plant performance and the cost of delivering biomethane affect its environmental and economic value.

What Are the Main Disadvantages of CBG?

CBG has clear potential, but several challenges limit its adoption. Producing vehicle-grade gas requires more processing than collecting raw biogas. Plants need reliable feedstock supplies, effective purification equipment, compression facilities and dependable buyers for the finished gas.

The location of a plant is particularly important. Agricultural waste is often bulky and costly to transport, while its availability can vary seasonally. Plants that operate below their intended capacity may struggle to recover their capital and operating costs. Digestate handling, waste segregation and methane leakage must also be managed properly.

For motorists, the practical limitation is availability. Even when a vehicle can use CBG, it needs access to a station selling the appropriate fuel. A vehicle's theoretical compatibility does not provide much benefit if refuelling is inconvenient or the supply is unreliable.

The IEA's assessment identifies cost competitiveness, supply logistics, plant utilisation and the availability of markets for by-products as important factors determining how quickly India's CBG sector can grow.

What Is the Future of CBG in India?

CBG's prospects depend on whether India can turn its large supply of organic waste into a reliable and competitively priced fuel. 

The government's GOBARdhan framework, the expansion of city-gas infrastructure and the requirement to increase CBG's share in the gas supply mix are intended to support that process.

For vehicle owners, a wider CBG supply could create another option for running compatible CNG vehicles. It could also help commercial operators diversify their fuel supply, particularly where a plant is located near a fleet depot or an established gas network.

However, a larger production target does not automatically guarantee lower prices. The cost of collecting waste, operating plants, purifying gas and moving it to customers must remain commercially manageable. The pace of station expansion and the reliability of local supply will matter just as much as the number of plants announced.

For motorcycles, wider CBG availability could support factory-designed gaseous-fuel models, but it does not remove the engineering and approval requirements involved in converting a petrol bike.

For cars, three-wheelers, buses and trucks already designed for CNG, compliant CBG is a more immediate alternative because the basic fuel compatibility already exists.

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