Petrol, also known as gasoline, is one of the most common fuel types for a vehicle. It is transparent and is derived via the fractional distillation of petroleum.  It is used in spark-ignited combustion engines and is available in multiple variants. 

Let's take a look at its pros and cons –

Pros

• It is cost-effective.
• Provides optimum acceleration.
• Petrol stations are easily available.
• Suitable for all types of ranges.

Cons

• This fuel emits a high level of toxic gases.
• It offers lower mileage than diesel.

Ideal for: 4-wheeler private cars, bikes

Price per litre: It is important to remember that the cost of gasoline differs in each state. Here is the table comprising the respective petrol prices in different Indian cities –

Despite the current scenario, diesel consumption witnessed recovery with a 27% rise. This speaks volumes about the popularity of this fuel. Like petrol, diesel is also obtained from the fractional distillation of petroleum oil that is specially tailored for a diesel engine.

Pro

• Offers value-for-money and is efficient for long travels.
• Features high torque and delivers excellent performance on express lane.
• It offers enhanced acceleration.

Cons

• Diesel engines require high maintenance and hence incur whopping expenses.
• A diesel engine does not cater to every make and model.

Ideal for: Trucks, trains, public buses

Price per litre:  Like petrol, diesel prices differ in each state. Here is a table for your reference –

CNG or Compressed Natural Gas comprises compressed methane less than 1% by volume.  It is one of the emerging fuel types for a car in urban areas with the primary objective to reduce pollution.

Pros

• It is free from lead and sulphur and is popularly known as "Green Fuel."
• Features a high auto-ignition temperature (540 degrees Celsius) and limited flammability range of 5%-15%. It implies that 5%-15% of CNG concentration in the air will not lead to accidental burning, thus, ensuring safety.
• It is safe to use as it is stored in certified cylinders, which are leak-proof. Since it is a light gas, it disperses and mixes with the air if it leaks.

Cons

• Limited availability of CNG stations, unlike petrol or diesel stations.
• It occupies at least 1/3rd of the vehicle's boot space. This makes it difficult for a sedan or other car owners to load the luggage in the cargo space.
• A CNG's car performance deteriorates after 3 to 4 years of usage. The engine's optimum performance also decreases by 10% after regular use for one year.
• It hampers the functionality of fuel injectors, making them dry quickly. It deteriorates engine performance in the long run.
• A CNG-powered vehicle has a lower fuel economy compared to other vehicles.
• The cost of conversion from conventional petrol or diesel-powered cars to CNG is high.

Ideal for: It is widely used in passenger cars. Models like Audi A5 2,0 TFSI CNG and BMW 3 Series (E36) can run on CNG.  Besides, vans, buses, trucks and more are suitable to run on CNG.

Price per litre: The following table illustrates the costs of CNG in 5 metropolitan cities in India –

The mixture of diesel with other oils produces bio-diesel. Converting vegetable oil, animal fat, and waste cooking oil into bio-diesel is known as transesterification. Since it constitutes natural ingredients, it is one of the best alternatives for biofuel.

Pros

• Environment-friendly and emits 11% lower carbon monoxide compared to other fuels.
• It features lower flashpoints and burns at a higher temperature. The storage of this fuel is simple as there is a lesser risk of sudden ignition.
• It is a non-toxic and renewable source of energy and, hence, ensures sustainability.
• Helps increase the lifespan of an engine. It acts as a solvent to remove the dirt deposited in the engine and restore its optimum performance, preventing frequent wear and tear.
• Vehicle-owners can use it in diesel engines with or without any modifications.
• This fuel reduces dependency on foreign countries for oil imports.

Cons

• It is not suitable for use in lower temperatures as it is susceptible to gelling. Gelling is a process in which a fuel's paraffin component solidifies and forms a gel-like part in colder temperatures.
• Although bio-diesel’s advantages include removing dirt from the engine, this dirt gets clogged into the gasket, leading to damage. It also damages an engine's rubber houses.
• The fuel efficiency of a bio-diesel powered vehicle is lower than others. It reduces fuel efficiency by 1%-2%.
• It is more expensive than petroleum.
• Bio-diesel is made from animal fat, vegetable oil, and the like. It affects food supply and increases the prices of the given products, leading to food shortages.
• It has regional restrictions as specific crop productions are not possible in every region.

Ideal for: Diesel-powered vehicles are fit to run on bio-diesel. Specifically manufactured trucks, vans, and SUVs are also approved to run on bio-diesel.

Price per litre: Here are the costs of bio-diesel in each metropolitan city –

LPG or Liquid Petroleum Gas is obtained from crude oil and natural gas. It constitutes hydrocarbon gases such as propane and butane.

Pros

• The high octane content in Auto LPG ensures a vehicle's optimum performance.
• LPG removes the carbon and acids from the engine, extending its longevity.
• It saves up to 40% of running costs compared to petrol and is safe from spillage.
• It emits 75% less carbon monoxide than petroleum and 60% less carbon dioxide than diesel.
• The conversion cost of LPG is affordable compared to CNG.
• It features anti-knocking characteristics, facilitating a higher octane number.

Cons 

• It is heavier than air. Hence, in case of leakage, it creates a suffocating environment.
• It has 10% lower fuel efficiency than petrol.
• Storage of LPG requires heavy cylinders, which ultimately increases the weight of the engine.

Ideal for: It is suitable for light-duty bio-fuel vehicles. Specific brands like Chevrolet and Maruti Suzuki manufacture LPG-powered cars in India.

Price per litre: Take a look at the costs of Auto LPG in each metropolitan city –