Nostalgia? Takes me back to the mid 70s. We had a Ford in he White House, and still no gas.

In the old days it was assumed that all gasoline was leaded.

When I was a kid it was call regular or unleaded.

For pretty much the same reasons that we speak of “hanging up” the telephone (or “dialing”, for that matter) and a number of other expressions that are carry-overs from a time when things were done differently than they are now.

We don’t have that.
We have regular-unleaded and ethanol.

In the 60’s and 70’s all gas had lead in it. It was California that started requiring gasolene to have no lead as it causes cancer in people and brain damage in children.

Why is it called gas when it is a liquid?

Actually lead is tetraethyl lead
Back in the day lead was added to gasoline to boost octane rating and reduce knock, and to help wear on engine valve seats. You can still buy leaded gasoline in some places for older boats and off road machines.
Unfortunately lead is toxic and destroys catalytic converters so gasoline was reformulated and car engines were modified to accept and run properly on unleaded fuel.

More to the point, why do you lot call it gas when it’s petrol?

Before 1973, all gasoline was called just that: gasoline. No gas that is sold in the US since 1973 can contain lead. So why not just call it “gasoline” like they did before they took the lead out??
Gas gauges still say “unleaded gas only” like there is a choice.

@kritiper . Not so, it was regular or ethyl (premium). There was also diesel and white.

Hoo, boy. Imagine the uproar if anyone tried to sell “white gas” in public these days, @MollyMcGuire.

@MollyMcGuire It was gasoline. Regular (leaded) gasoline and ethyl (premium leaded) gasoline. Diesel is not gasoline (leaded or unleaded) and white gas was not used in cars because it was not leaded (made for gasoline engines, lead being added to increase octane and lubricate the upper cylinder). When lead was removed, other additives were introduced to the gasoline to replace the lead thus creating “unleaded.” There is no leaded gasoline available for todays gasoline engines. So why call it “unleaded?”
@CWOTUS You can buy white gas as “Coleman” fuel for stoves and lanterns. That’s what white gas was used for.

@kritiper It was regular or ethyl just like I said. Until unleaded came on the scene no one mentioned the lead. You are also wrong about white gas too. Back then we burned white gas from Amoco in our outboard motor boats. It not just for camping lanterns.

@MollyMcGuire @kritiper Like they used to say in the Certs commercials: “Stop. You’re both right!”
Coleman Fuel was called White gas.
And unleaded was called white gas too.

“Coleman fuel is a petroleum naphtha product marketed by The Coleman Company. Historically called white gas (not white spirit), it is a liquid petroleum fuel (100% light hydrotreated distillate) usually sold in one gallon cans.[1] It is used primarily for fueling lanterns and camp stoves.”

@MollyMcGuire I guess you missed the point of the question.
Why call it unleaded when all a person can get for their car these days is unleaded? It doesn’t need to say “unleaded gas only” on your car since unleaded is all there is. All that is required to say is “regular,” “midgrade,” or “premium.”