What was leaded - unleaded transition like? Octane?

[TmanP]

Was wondering recently what the transition from leaded to unleaded fuel was like, particularly the octane options. My assumption is that stations with three grades would have had one "regular leaded" (what was its octane, usually? I'm assuming its octane may have been higher due to the addition of lead to the base fuel - was it 89?), and one "unleaded" (assuming that it was likely 87 octane).

Was the premium typically leaded or unleaded in the transition era (say, the 1980s)? Or did that depend on the station?

From what I can tell, unleaded was typically a bit more expensive than leaded when they were both offered, was that true? (All of these assumptions are from old photos on Google.) Also, was the transition to strictly unleaded pretty quick once mandated by law? Or did some stations go all unleaded earlier?

 

[Slick3914]

I remember leaded gas being 89 octane

 

[BMWTurboDzl]

I remember it not being a big deal.

 

[Chris142]

Leased was regular here.. 87

Premium was unleaded and was 91 or 92

 

[JeffKeryk]

I used to mix 91 and 87. That was the secret!

 

[RedSpider]

If I remember right, our leaded regular was 89, and smelled a bit different (better) than unleaded, and was a bit darker in color. It was a few pennies cheaper per gallon and you could get a small plastic adapter to put leaded into an unleaded-only car. I worked at a small gas station part time during high school and would see lots of people put the adapter on the fuel nozzle before putting the nozzle into the car filler. I had one myself even though my '77 Mustang had a cat (hollowed out because, according to my friend, "way more power, bro"). Other than that, its wasnt a big deal.

 

[samven]

Octane was calculated differently, premium leaded was 100 octane, regular was 93 octane I think and super premium was 104. Sunoco used to have a pump to select up to 104. The transfer to mtbe as a substitute for lead was gradual and octane ratings started to be calculated differently.

 

[joekingcorvette]

I remember premium was a really nice pink color. Most old time consumers were skeptical to run the unleaded gasoline even though their vehicle could run on it. It was not a big deal from what I remember. Most people agreed that the unleaded gas would run cleaner but almost everyone knew it shouldn't be run in old lawn mowers and small engines including marine engines due to it would destroy some seals and gas lines and was bad for carburetor parts.

 

[SC Maintenance]

Am I wrong in thinking that right at the end leaded gas became more expensive than unleaded?

Then it just went away. Not all stations at once but pretty quick.

I think that was early 90's? The issue was if you had a car from the early 70's the valve seats needed the lead lubrication. But still, those cars were 15+ years at that point. I wonder if thats why all those early 70's cars just vanished?

 

[spackard]

Unleaded was always sold for more money than leaded. Buddies and I were Union 76 loyalists.
Occasionally I’d fill up with 100LL at the airport and was sure I’d get better acceleration.

Eventually it was down to adding a lead substitute from a can.

 

[Speedbird001]

My first car; a '66 Mustang with a '69 250 ci straight 6. I had it tuned as best I could and ignition advanced so I would not ping with unleaded 92/93 (But if definetly would ping with the regular 87). There was an OPE shop the next town over that sold 87 leaded gas... The Mustang also would NOT ping if I used that.

So, based on my experience in 1991, 87 leaded was the same as 92/93 unleaded

 

[chainblu]

Am I wrong in thinking that right at the end leaded gas became more expensive than unleaded?

That is correct. Also, pretty much when I stopped buying it.
I had an older vehicle with a late model (unleaded) engine, so I could run either one, which was great for pump availability.

But yeah, as soon as leaded became a few cents more expensive, that was it.

 

[1000MPH]

When did they start calling it premium? I remember when it was called Ethyl or Super.

 

[Jetronic]

Was wondering recently what the transition from leaded to unleaded fuel was like, particularly the octane options. My assumption is that stations with three grades would have had one "regular leaded" (what was its octane, usually? I'm assuming its octane may have been higher due to the addition of lead to the base fuel - was it 89?), and one "unleaded" (assuming that it was likely 87 octane).

Was the premium typically leaded or unleaded in the transition era (say, the 1980s)? Or did that depend on the station?

From what I can tell, unleaded was typically a bit more expensive than leaded when they were both offered, was that true? (All of these assumptions are from old photos on Google.) Also, was the transition to strictly unleaded pretty quick once mandated by law? Or did some stations go all unleaded earlier?

For us there was no difference, 95 RON and 98 RON. But I seem to remember 98 RON leaded was available for longer. The change must've been around 1997, leaded 98 was still available when I started driving, don't remember seeing 95 leaded at the time.

 

[hank2]

Leaded regular gasoline had been 90 "pump octane" for years, then lowered to 89 when the lead level was reduced in the 80's. Leaded premium was anywhere from 96 to 98 PO. When unleaded was available (1974?) it was offered in a sub-regular or economy grade 87 pump octane. Continuing to this day. The new emissions/malaise car engines of the time had pretty low static compression ratios, so 87 was enough.

I believe the leaded premium went away by about the mid 1980's. Leaded regular went to about 1992 but was gone sooner in some states. My last leaded regular fuel car ownership was 1983-88. After that I didn't pay much attention to the remaining years. I'm pretty sure that leaded regular was a little cheaper than the 87 unleaded during most of that time. The 89 PO midgrade that's still around was there at first as a replacement for the old "real" regular fuel.

After leaded premium went away, many with older cars would mix unleaded premium and leaded regular. They thought they were magically creating something higher octane than either the 93 PO or 89 PO leaded. They were only creating very slightly leaded 91 PO.

 

[BobsArmory]

Had a 73 Bronco back then when I was in High School. There was one gas station that had premium leaded with 10% alcohol. Don't remember the octane but it was the highest in town, that was where I filled up. the scent was better than unleaded. We did hollow out converters or install "test pipes" in my buddies cars so we could use leaded in them.

I remember all the angry people. Very similar to the Diesel DEF Fluid DPF hate we see today.

 

[97prizm]

Was wondering recently what the transition from leaded to unleaded fuel was like, particularly the octane options. My assumption is that stations with three grades would have had one "regular leaded" (what was its octane, usually? I'm assuming its octane may have been higher due to the addition of lead to the base fuel - was it 89?), and one "unleaded" (assuming that it was likely 87 octane).

Was the premium typically leaded or unleaded in the transition era (say, the 1980s)? Or did that depend on the station?

From what I can tell, unleaded was typically a bit more expensive than leaded when they were both offered, was that true? (All of these assumptions are from old photos on Google.) Also, was the transition to strictly unleaded pretty quick once mandated by law? Or did some stations go all unleaded earlier?

From reading old articles in California at least 87,89, 92 was unleaded, leaded was 88 octane which seems low especially with big block classic cars not having anti-knock. California banned leaded automotive gas January 1 1992. I did find an article years ago from the mid 90's where people who daily drove 1974 and older cars were complaining and freaking out about what they were going to do for gas.

 

[fantastic]

The issue was if you had a car from the early 70's the valve seats needed the lead lubrication. But still, those cars were 15+ years at that point. I wonder if thats why all those early 70's cars just vanished?

When I had my 68 Fury in the late 90's & early 00's it was run on Unleaded Fuel. It did say to use "Leaded Fuel" on the dash. Now that you mentioned "lubrication" it could be why we were constantly changing the mechanical fuel pumps on that 318 5.2L.

 

[Boomer]

I think lubrication from unleaded gas referred to the deposit of lead oxide on the valves and valve seats that prevented metal transfer. When they went to unleaded gas, valves had to be hardened to prevent this and it was a major reason why you could not run unleaded gas in cars with the old style valves. Lead oxide also built up in the exhaust pipes and moisture from engine starts formed plumbic acid which is what ate through the exhaust systems back then.

 

[kschachn]

When I had my 68 Fury in the late 90's & early 00's it was run on Unleaded Fuel. It did say to use "Leaded Fuel" on the dash. Now that you mentioned "lubrication" it could be why we were constantly changing the mechanical fuel pumps on that 318 5.2L.

TEL didn't do anything for lubrication until it was decomposed in the combustion chamber.