The Math Doesn’t Math: The True Cost of India’s E20 Ethanol Policy

Suppose you have an e10 car. The price of e10 petrol is 100 Rs/l. your car gives a mileage of 20kmpl and you drive 100kms a day.

fuel needed 100/20 = 5 liters

cost of fuel = 100 x 5 = 500

Now government starts blending petrol with 20% ethanol, the price of petrol is same and your usage is also same.

As per the some experts, you will feel a drop of 10% in the mileage( my real life experience tells me that the fuel efficiency goes down by 20% min). But we will take 10% dip in mileage just to respect our ethanol mantri.

now to drive 100 kms with e20 blending, the price is

Fuel needed 100/18 = 5.56 liters.

cost of fuel = 5.56 x 100 = 556.

We will not talk about that the e20 fuel government is selling you is at the same price of e10 and the government is actually saving 4 rupees on every liter as blending grade ethanol is 40% cheaper than petrol if we even consider e10 as pure petrol.

So you will be paying 56 rupees per day just for the sustainability. But is this blending actually sustainable?

So ethanol is majorly extracted from 3 sources and we will, from end to start calculate the water used in making 1 liter of ethnol

Rice-based Ethanol: Up to 10,790 liters of water per liter of ethanol (since growing paddy requires enormous groundwater irrigation).

Sugarcane-based Ethanol: 1,600 to 3,600 liters of water.

Corn/Maize-based Ethanol: 10 to 17 liters in rain-fed regions (like parts of the US), but up to 4,670 liters if grown in highly irrigated areas.

Sugarcane based production wastes less amount of water and our ethanol minister also owns sugar mills just for saving water, so our calculations will be based on that.

So you are using 5.56 liters of e20 petrol as compared to 5 liters e10 petrol. so in this 5.56 liters of petrol, the quantity of ethanol when you consider e10 as pure petrol.

10% of 5.56 = 556ml of ethanol.

The sugarcane takes around 1600–3600 liters of water, but as we are fan of our ethanol mantri, we will calculate the wastage on 1600 liters.

Amount of water wasted to make 556ml of ethanol

0.556 liters × 1,600 liters = 889.6 liters

In short you are wasting 889 liters of water every day in a country having water scarcity in many parts, just for what? for the sake of sustainability and prosperity of our beloved mantri ji.

But the story does not end here

Lets talk about the pure petrol you are using in both the cases

CASE 1 When you are using e10 petrol, driving 100km @ 100 rupees per liter price and fuel consumption is 5 liter.

90% of 5 liter = 4.500 liters of pure petrol

CASE 2 When you are using e20 petrol, driving 100km @ 100 rupees per liter price and fuel consumption is 5.56 liter

80% of 5.56 liter = 4.448 liters of pure petrol.

So if we calculate the net difference in petrol

4.500–4.448 = 0.0052 liters

Guys you are saving 52 ml of petrol import and wasting 889.6 liters of water in your daily commute, that too if you drive cars like alto, wagon r (even they dont give 20kmpl in city on ac).

We will not talk about the maintenance aspect, as it will hurt your bum more.

I rest my case here, if you have any questions, or my calculations are wrong somewhere, comments are welcome.