• HelixDab2@lemm.ee
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      2 days ago

      Lead in gasoline was a stop-gap solution. If I remember correctly , it was added because we didn’t have the technology at the time to refine gas sufficiently to get the octane levels necessary to prevent pre-ignition of fuel (which causes rod knock) at a reasonable cost. Tetraethyl lead effectively increased the octane level/resistance to pre-ignition. As a side benefit, the lead slightly lubricated the valves and valve seats so that they lasted for tens of thousands of miles, instead of needing to be reground every few thousand miles.

      It was a stupid stop-gap though, esp. since the dangers of lead were well known by then.

      • ColeSloth@discuss.tchncs.de
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        2 days ago

        You’re mostly correct. It was an additive to raise the octane rating and did lubricate. However, it wasn’t a gas refinement issue that caused the need. An octane boosting additive has been needed ever since, right up to today. Now the octane booster used is ethanol, mostly.

        Race cars and many airplanes still use lead. We’re still making people dumber. Just at a lesser scale.

        • HelixDab2@lemm.ee
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          4 hours ago

          You can absolutely get high octane ethanol-free gas; there’s a place near me that sells it. I know that a lot of people with motorcycles use it, because inline four cylinder motorcycle engines tend to be high compression, and motorcycle people tend to be almost religious about not using ethanol. (Which is unnecessary; assuming your motorcycle is fuel injected, the only risk with ethanol is storage for several months at a time with a full tank of gas. If you do that, then you’re going to end up with water in your gas, because ethanol is hygroscopic. As long as you keep riding regularly, or empty your tank and run the motor dry before storing it for more than a month, you’ll be fine with ethanol in your gas.) I know of at least once place near-ish to me that sells 110 octane ethanol- and lead-free racing gas. Ethanol-free high octane fuels tend to be about 25-50% more expensive than fuels with ethanol.

          Avgas is another story. The odds are pretty good from what I can tell that any prop airplane is going to need gas with tetraethyl lead. To me, that sounds like a good reason to remove them all from service in favor of jets, but I think that jets have a higher stall speed, which can be a problem, esp. in backwoods areas.

          (Jet-a and jet-a1 are kerosene derivatives, and don’t have lead.)

          • ColeSloth@discuss.tchncs.de
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            2 hours ago

            Ethanol free gas doesn’t mean there aren’t any no knock additives. There’s several more things besides Ethanol that can be added to gasoline that will increase the octane. Strictly speaking, “gasoline” isn’t even one exact formulation.

            Short of it is that ethanol free gas just means it’s using something else to boost the octane.

        • Flocklesscrow@lemm.ee
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          2 days ago

          If you want a sad rabbithole, look at the cancer rates around small airports, which are often much closer to where people live.

          • 667@lemmy.radio
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            1 day ago

            While it’s no consolation to these current people, they are trying to make the switch to lead-free aviation fuel. It’s partly a regulatory nightmare, and partly a genuine safety challenge; mandating a fuel change in aviation without adequate research and understanding can result in unexpected engine malfunctions.

            • HelixDab2@lemm.ee
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              4 hours ago

              unexpected engine malfunctions

              On the other side of that is the known problems that lead causes. Seems to me that the best solution is to give everyone a cut off point, and say, hey, when we hit this point, you’re going to have to retire that engine, and get one that’s known to be good with lead-free avgas. Sure, it’s a cost, but that’s why you give people time to prepare.