Eli5 : Why Didn’t Thomas Midgley Jr Use Ethanol to boost octane instead of Tetra-ethyl-lead?

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Watched a few video’s on this problem, i know that ethanol was available before Tetra ethyl lead, just wondering why ethanol was not used to boost the octane to solve the “pinging/detonation” Problem?

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6 Answers

Anonymous 0 Comments

It was a matter of cost. Petrol is extremely cheap. It is only recently with lots of US government subsidies and high oil prices that ethanol is even in the same ballpark in terms of costs. And you need quite a lot of ethanol to make any significant impact on the octane rating of the fuel. But you only need a tiny bit of TEL to do the same. We are talking about a maximum of 0.2g og TEL per liter petrol in passenger cars. So even though TEL is more expensive per volume the amount you need as a fuel additive makes it a much cheaper alternative to ethanol. In addition to this TEL could be patented so everyone who put TEL in their fuel had to pay a license fee to General Motors.

Anonymous 0 Comments

The goal of adding lead to gasoline was not to increase the octane rating, but rather to reduce engine knocking. Knocking is when an incomplete combustion occurs within the cylinder, imparting a sideways force on the piston. This causes the piston to slam into the side of the cylinder, causing a loud ping or a knock sound. By adding tetra-ethyl lead to gasoline, Midgley discovered that a uniform combustion could occur within the gasoline, resulting in minimal lateral force on the piston.

Octane rating is actually a measure of how much you can compress a fuel before it spontaneously explodes, so while the addition of the tetra-ethyl lead did alter the octane rating of the fuel, this was not the goal but only a means to accomplish the goal.

Anonymous 0 Comments

It was a matter of cost. Petrol is extremely cheap. It is only recently with lots of US government subsidies and high oil prices that ethanol is even in the same ballpark in terms of costs. And you need quite a lot of ethanol to make any significant impact on the octane rating of the fuel. But you only need a tiny bit of TEL to do the same. We are talking about a maximum of 0.2g og TEL per liter petrol in passenger cars. So even though TEL is more expensive per volume the amount you need as a fuel additive makes it a much cheaper alternative to ethanol. In addition to this TEL could be patented so everyone who put TEL in their fuel had to pay a license fee to General Motors.

Anonymous 0 Comments

It was a matter of cost. Petrol is extremely cheap. It is only recently with lots of US government subsidies and high oil prices that ethanol is even in the same ballpark in terms of costs. And you need quite a lot of ethanol to make any significant impact on the octane rating of the fuel. But you only need a tiny bit of TEL to do the same. We are talking about a maximum of 0.2g og TEL per liter petrol in passenger cars. So even though TEL is more expensive per volume the amount you need as a fuel additive makes it a much cheaper alternative to ethanol. In addition to this TEL could be patented so everyone who put TEL in their fuel had to pay a license fee to General Motors.

Anonymous 0 Comments

The goal of adding lead to gasoline was not to increase the octane rating, but rather to reduce engine knocking. Knocking is when an incomplete combustion occurs within the cylinder, imparting a sideways force on the piston. This causes the piston to slam into the side of the cylinder, causing a loud ping or a knock sound. By adding tetra-ethyl lead to gasoline, Midgley discovered that a uniform combustion could occur within the gasoline, resulting in minimal lateral force on the piston.

Octane rating is actually a measure of how much you can compress a fuel before it spontaneously explodes, so while the addition of the tetra-ethyl lead did alter the octane rating of the fuel, this was not the goal but only a means to accomplish the goal.

Anonymous 0 Comments

The goal of adding lead to gasoline was not to increase the octane rating, but rather to reduce engine knocking. Knocking is when an incomplete combustion occurs within the cylinder, imparting a sideways force on the piston. This causes the piston to slam into the side of the cylinder, causing a loud ping or a knock sound. By adding tetra-ethyl lead to gasoline, Midgley discovered that a uniform combustion could occur within the gasoline, resulting in minimal lateral force on the piston.

Octane rating is actually a measure of how much you can compress a fuel before it spontaneously explodes, so while the addition of the tetra-ethyl lead did alter the octane rating of the fuel, this was not the goal but only a means to accomplish the goal.