Leaded gasoline was a staple in the US and all over the world for decades. We have long known that lead is bad for our health and the environment, but somehow lead—more specifically tetraethyl lead or (TEL) wasn’t officially phased out of use for fuel in motor vehicles in the US until 1996. Classic and vintage cars that were originally designed to run on leaded gas even need to be retrofitted by an experienced car mechanic so that they can run on unleaded fuel. Toxic or not, lead was an important additive to fuel. Why was it added? Let’s take a closer look.
Don’t Come Knocking: Lead is An Easy Octane Enhancer
When you go to a gas pump these days there are a few options when it comes to gas octanes. Many daily drivers these days, including most Volkswagen, are designed to run on something with a lower octane rating like 87. But, if you have something with a high-performance engine like a BMW, Audi, or Mercedes, you will need a premium octane rating in the 91-94 range.
The higher the octane rating on a car, the more heat and pressure that the gasoline can withstand before spontaneously combusting. Cars with high-performance engines are designed to compress the fuel/air mixture in the engine cylinders more severely before the spark plugs ignite. What this means is that if you put gas with a lower octane rating in a car that expects a high-octane fuel, the gas in the chambers may spontaneously combust out of sequence before it is actually ignited by the spark plug, causing what is known as an engine knock.
Any modern car has sensors that can adjust the ignition of the spark plug to prevent engine knock, but in the 1920s, having a higher octane was crucial for a smoothly running high-performance engine. When it was discovered that TEL was a relatively cheap and effective way to increase the octane of gasoline, it seemed like a great option. The use of leaded gasoline allowed for the development of more powerful engines. It also was found to help cool the intake valves of engines running the fuel and was a “buffer against microwelds forming between exhaust valves and their seats.” In some ways it seemed like a perfect solution. It allowed for the production of higher-performance engines, and allowed them to withstand more wear and tear. Except for the highly toxic part.
Lead’s Unfortunate Legacy: It’s In More Than Paint Chips
It doesn’t take a genius to know that you shouldn’t chew on paint chips from an old house because of the potential lead content. It was deemed safe, however, for the lead to be aerosolized and spread throughout the air from every car’s tailpipe. Even in the 1920s it wasn’t much of a secret that lead in gasoline wasn’t great for health. Lead known to be dangerous since at least the 1800s, and even GM—who patented the use of TEL as an anti-knocking agent—preferred to market it as “ethyl” instead of “lead” because of all of the bad press for lead.
It became even more apparent when employees who worked in facilities that made the TEL had some alarming experiences working closely with concentrated amounts of the chemical. One facility was referred to “house of butterflies” because the workers regularly had hallucinations of bugs due to the extreme amount of lead during production. Another facility referred to the TEL production area as the “loony gas building,” and by 1924 there were at least 5 deaths and even more hospitalizations from the intense concentration of lead that the workers were coming in contact with. With the addition of additional precautions, it became less dangerous to work in facilities that produced TEL, but it still remained dangerous to use.
Money Talks: Lead Was the Cheapest Octane Enhancer
Despite all of these health hazards, lead was the standard additive to gasoline for decades. Unsurprisingly enough, it is because it was the cheapest option. While modern gas pumps will add a percentage of ethanol to stabilize and raise the octane level of gasoline, this option was both known about and decided against in the 1920s because it was deemed too expensive. As public concern was raised, the dangers of lead kept being pushed under the rug because “For the next four decades, all studies of the use of tetraethyl lead were conducted by laboratories and scientists funded by the Ethyl Corporation and General Motors,” who wanted to make sure that people would keep buying the leaded gas.
It wasn’t until Richard Nixon signed the Clean Air Act in 1970 that the real phaseout of leaded gasoline began. The Act required all new cars to have a vastly reduced amount of carbon monoxide emissions, which was ultimately accomplished though the addition of catalytic converters to all new cars. Leaded gas destroyed catalytic converters, which meant TEL’s days were numbered. Kind of.
The Alarming Effects and Ongoing Legacy Of Tetraethyl Lead
TEL wasn’t officially phased out at the US gas pump until 1996, and though you can’t get it to fill up your pre-catalytic converter convertible anymore, leaded fuel it is still the standard fuel for recreational aviation purposes. This is in main part because of the stringent testing required to change any rules and regulations for the Federal Aviation Administration (FAA). What’s even more alarming, however, is the effect that the proliferation of lead in the environment had on the population.
Statistical comparisons put together by the economist Jessica Reyes seem to indicate that the decrease of lead in the atmosphere led to a decrease in violent crime. Since states phased out the use of lead at different times, she was able to compare local violent crime rates to the amount of lead in the environment. Her conclusions found that 20 years after the beginning of lead’s phaseout—enough for a new generation of kids to grow up with a less concentrated exposure to lead—that 56% of the drop in violent crime was likely due to differences of lead in the environment.
You Don’t Need Lead For a High Performance Automobile
Luckily we live in a time where lead isn’t being pumped out at every intersection across the US. But that doesn’t mean that the pre-1970 classic beauties need to be removed from the roads either. At this point in time most classic cars have been upgraded with more durable seals so that the lack of extra lead lubrication won’t affect their performance as long as you run a high enough octane fuel. When it comes to a classic car, it’s worth it to get the good stuff. If you aren’t sure whether your cylinder heads have been upgraded, it’s a good idea to call your local auto repair shop that specializes in vintage car repair. They can give you the advice or upgrades that you need to keep your classic car running for decades to come.
