What happened to gasoline in the mid 1970s?

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One thing that I see missing in this discussion (and I don't claim to be an expert on this) is that how octane ratings were determined changed around 73-75. Before that producers has their own systems for making octane claims. The Government standardized how the octane ratings were determined (thus the federal octane sticker on the pump). This meant that consumers could compare apples to apples when buying gas, and you couldn't be taken in by unrealistic octane claims.

The biggest thing that happened was that the cost of gas went through the roof!!!! Sometimes stations were charging as much as 42 cents a gallon!!!! I remember my Dad buying a slant 6 Dart in 75 to replace our V-8 1970 model, and used muscle cars were selling for bargain basement prices. in 1976 I tried my damndest to get $1200 together to buy a beautiful low mileage 440 4 speed GTX from a Plymouth dealership mechanic, but I just couldn't come up with that much...
 
One thing that I see missing in this discussion (and I don't claim to be an expert on this) is that how octane ratings were determined changed around 73-75. Before that producers has their own systems for making octane claims.
here
An interesting discussion of how octane rating changed from RON to MON. So comparing old and new octane numbers is like comparing gross and net engine horsepower.

What octane level was the standard for premium in 1970? - ClassicOldsmobile.com
And in the US its been standardized as the average, also refered to as Anti Knock Index (AKI).
Per the query on the Oldsmobile forum, my parents had mom's '69 318 Belvidere tuned for American Premium (Super, unleaded). In other words the timing was advanced a little. Was this common? I doubt it.

Sunoco still makes 100 (R+M)/2 octane fuel that is street legal inside and outside California. A quick search indicates it is very expensive.
All race fuels are expensive. Any fuel sold for street use also has road taxes added to them.
I bought 5 gallons of GTX at 10.50 per gal this spring and considered that a good price.
 
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Regulatory timeline.
This doesn't cover the changes made by the refining and retail suppliers on their own due to other factors (wars in the middle east, profits, market demand, whatever)
Interesting the NY Times article about 1971 cars and fuels indicates a major shift in gasoline composition (and confusion) at the time. This is several years before GM helped the Feds deside cats were essential.
Auto Makers and Oil Industry Get the Lead Out’ (Published 1970)
 
FWIW This is what Pa checked at the tailpipe. (This is the only vehicle I know I still have the results for.)
This was a rolling sniff test. My previous cars in NJ only had to pass at idle. I think my '67 was exempt or had a very easy requirement, but '68 definately was not.
View attachment 1715737876

Right! WHERE is the measurement for unburned fuel? There is none. Know why? Because the gubmint isn't interested in making vehicles more efficient. They got there once. Remember the little cars from 89 to about 2003? They kept getting better and better mileage until.....wait for it.......the GUBMINT stepped in and made automakers TUNE for ethanol. We had an 02 Corolla I bought for Kitty brand new. Little 4cyl, variable valve timing....all that "new" stuff. That car knocked off consistent 46MPG on the highway LOADED with Kitty, me, our son and stepdaughter packed SLAM FULL of 2 womens' worth of crap. Still.....46MPG. Then long about 2003, all that went to hell. You don't see those mileage ratings very much now. Before that, they were getting up there. Some of those Geo Metro cars got 60 plus.

If some of yall think this is about pollution and clean cars, you're a FOOL. It's always about the money. It always has been. My Uncle is probably one of if not THE MOST respected economist in the world. He's written many times about the uselessness of gubmint regulation and in particular how useless the EPA is. He's right, too. They don't do anything they were created to to. But they do make the gubmint a lot of money.
 
Interesting the NY Times article about 1971 cars and fuels indicates a major shift in gasoline composition (and confusion) at the time. This is several years before GM helped the Feds deside cats were essential.
Auto Makers and Oil Industry Get the Lead Out’ (Published 1970)

Yeah I think GM was the first to use air pumps. The 70 or 71 model were the first, I believe. They even put air pumps on the LS6 450HP 454 cars.....with no cats. Talk about useless dilution of the exhaust. SAME pollution, just more air. lol
 
I'll quibble that when an engine is producing near its maximum torque and power (for any given rpm) the exhaust HCs are high. So in those instances more HC in the exhaust occurs when the engine is more mechanically efficient, even though its chemically less so.

I suppose the explanation is the most power is made when the most oxygen is used for burning.

I agree...and "I'll" come back and quibble that the amount of hydrocarbons "flashed" from evaporation pales in comparison to those released when fuel is burned.
 
i think the reference is to unburned fuel in exhaust. The theory is that the stoichiometric ratio is never perfect and the mixture doesn't completely combust there by leaving unburned fuel in the exhaust stream. The "evaporative" emissions went through tubes to a charcoal canister somewhere on the vehicle, today with Fuel injection the whole system is sealed as far as evaporative emissions (fuel vapor). The cat converter is there to process unburned hydrocarbons and convert the gasses to inert gasses by way of catalyst. water is one of the by products you can see it coming out of the exhaust pipe.
 
Right! WHERE is the measurement for unburned fuel? There is none. Know why? Because the gubmint isn't interested in making vehicles more efficient. They got there once. Remember the little cars from 89 to about 2003? They kept getting better and better mileage until.....wait for it.......the GUBMINT stepped in and made automakers TUNE for ethanol. We had an 02 Corolla I bought for Kitty brand new. Little 4cyl, variable valve timing....all that "new" stuff. That car knocked off consistent 46MPG on the highway LOADED with Kitty, me, our son and stepdaughter packed SLAM FULL of 2 womens' worth of crap. Still.....46MPG. Then long about 2003, all that went to hell. You don't see those mileage ratings very much now. Before that, they were getting up there. Some of those Geo Metro cars got 60 plus.

If some of yall think this is about pollution and clean cars, you're a FOOL. It's always about the money. It always has been. My Uncle is probably one of if not THE MOST respected economist in the world. He's written many times about the uselessness of gubmint regulation and in particular how useless the EPA is. He's right, too. They don't do anything they were created to to. But they do make the gubmint a lot of money.

What money is in ethanol that is motivating the government?

It goes back way farther than 1989

the EPA rated the 1.3-liter four-cylinder 1984 Honda CRX at an astonishing 68 MPG in highway driving

In an effort to standardize production, Honda used the 1.5-liter four in HF (High Fuel economy) versions beginning in 1985. Thanks in part to a change in the EPA rating system, the car's fuel economy rating fell from the original 68 MPG highway to a still-impressive (and somewhat conservative) 42 MPG highway. Owners frequently reported highway fuel economy in excess of 50 MPG, and CRX fans are quick to point out that modern hybrid automobiles, for all their expense and complexity, struggle to top this number.

https://www.hemmings.com/stories/2013/06/24/lost-cars-of-the-1980s-honda-civic-crx

We are 37 years later and cars are still not doing way better. They should be doing way better.
 
I agree...and "I'll" come back and quibble that the amount of hydrocarbons "flashed" from evaporation pales in comparison to those released when fuel is burned.

Surprisingly, they're comparable. Here's a study that tested several 60-70's era vehicles : https://www.tandfonline.com/doi/pdf/10.1080/00022470.1980.10465171?needAccess=true

The study basically showed that 1/3-1/2 of the total vehicles' HC emissions were from evaporative sources.

Interestingly, California's emission inventory data shows that light-duty auto evap hydrocarbon emissions are slightly greater than those from exhaust.
 
The Air Pumps (Smog Pumps) had an additional effect on exhaust gas emissions. By adding air to the exhaust, tailpipe emissions were diluted giving cleaner readings.
I mentioned this in post # 3. The smog/air pump wasn't meant to dilute the exhaust, it was to mix fresh air to the exhaust to create a chemical reaction, raise the exhaust temperature to burn more completely.
Catalytic converter science improved dramatically since 1975 too. High flow converters, multiple converters, heated oxygen sensors, etc.
 
Right! WHERE is the measurement for unburned fuel? There is none. Know why? Because the gubmint isn't interested in making vehicles more efficient. They got there once. Remember the little cars from 89 to about 2003? They kept getting better and better mileage until.....wait for it.......the GUBMINT stepped in and made automakers TUNE for ethanol. We had an 02 Corolla I bought for Kitty brand new. Little 4cyl, variable valve timing....all that "new" stuff. That car knocked off consistent 46MPG on the highway LOADED with Kitty, me, our son and stepdaughter packed SLAM FULL of 2 womens' worth of crap. Still.....46MPG. Then long about 2003, all that went to hell. You don't see those mileage ratings very much now. Before that, they were getting up there. Some of those Geo Metro cars got 60 plus.

If some of yall think this is about pollution and clean cars, you're a FOOL. It's always about the money. It always has been. My Uncle is probably one of if not THE MOST respected economist in the world. He's written many times about the uselessness of gubmint regulation and in particular how useless the EPA is. He's right, too. They don't do anything they were created to to. But they do make the gubmint a lot of money.


Ok, PM me some links to anything anything your uncle wrote. I’d love to read any and all of it. And I’m serious.
 
My Uncle is probably one of if not THE MOST respected economist in the world.

That's a very big claim considering there are many schools of economic thought/ideology in the field of "Economics" and each has their chosen high priest. I'd like to know who your uncle is too. What University did he teach at?
 
That's a very big claim considering there are many schools of economic thought/ideology in the field of "Economics" and each has their chosen high priest. I'd like to know who your uncle is too. What University did he teach at?

Clemson. He's been associated with Clemson University in some capacity for over fifty years. He served as interim Dean for a time. He served as Executive Director of the Federal Trade Commission under Reagan for both terms. It's a big claim, because it's a big fact.

Here he is.

Bruce Yandle
 
That's a very big claim considering there are many schools of economic thought/ideology in the field of "Economics" and each has their chosen high priest. I'd like to know who your uncle is too. What University did he teach at?

...and his wiki page.

Bruce Yandle - Wikipedia
 
WHERE is the measurement for unburned fuel?
upload_2021-5-16_18-6-2.png


the amount of hydrocarbons "flashed" from evaporation pales in comparison to those released when fuel is burned.
I'll go with the info @MOPOWER linked to for whether they were generally in the same order of magnitude.
But my nose tells me that in the Spring (like now) I can often smell the fuel vapor on both my '67 (no vapor capture) and my '85 with its vapor capture system mostly all there.

Somewhat related was what I thought was a veery interesting discovery was how much vapor even an open air cleaner captures when an engine is running at idle.
This is screenshot from a datalog where I removed the air cleaner lid while idling in the Summer.
Yellow markers on timeline are when the air cleaner lid was removed and then reinstalled.
upload_2021-5-16_18-20-12.png

Recording time in min:seconds along bottom.
There may have still been some winter fuel in the tank. I'd have to look to check that.

i think the reference is to unburned fuel in exhaust. The theory is that the stoichiometric ratio is never perfect and the mixture doesn't completely combust there by leaving unburned fuel in the exhaust stream.

I think the reference is whatever the person writing about wants it to be, whether its the stuff out the vents or the stuff out thte tailpipe. Its all good discussion. :) But I too was focusing on tailpipe.

The cat converter is there to process unburned hydrocarbons and convert the gasses to inert gasses by way of catalyst
Looks like you're correct. The first generation of cats did reduce HCs as well as CO
upload_2021-5-16_18-28-3.png


What money is in ethanol that is motivating the government?
There are two main groups that are (or were) lobbying for ethanol, and there may be others.
The automobile manufacture's were pushing for fuel changes that would help them meet both emissions and better corporate fuel milage overall. Do some web searching for Reformulated gasoline and ethanol and you'll find everythiung from academic papers to trade industry backed promotional/educational material.
Ethanol is an oxygenate and it can improve milage if the car is set up for it. I'll say this. This current generation of E10 RFG runs a heck of a lot better than the MTBE stuff we had for a few years. That stuff was horrible (and pretty toxic too).

According to the timeline, Calf banned MTBE in 2004, and the Federal oxygenate requirement was dropped in '06. The concept (as I understand it) was that the car companies only needed it for a few years to bridge the time needed to develop and produce slightly higher milage and lower emissions cars and trucks.
upload_2021-5-16_18-41-22.png

However at the same time the oxygenate was dropped, the "Renewable Fuels Standard" was implemented.
One perspective is the reason given on the timeline. Another is that the corn producers and industries that had grown to support the need for eth in fuel didn't want to see it go away.

We are 37 years later and cars are still not doing way better. They should be doing way better.
Yea I agree. It seems kindof ridiculous how poor the fuel milage is on many vehicles today that have the benefit of more than 3 gears in the transmission. I think part of it is perceived safety and 'comforts' and all that stuff that adds weight.
Ironicly it seems to me behaviours have changed a lot too. I see a lot more people sitting in their cars with the engine idling than when I was kid. Now maybe its location not time related. Dunno. Just my observations.
 
View attachment 1715738427


I'll go with the info @MOPOWER linked to for whether they were generally in the same order of magnitude.
But my nose tells me that in the Spring (like now) I can often smell the fuel vapor on both my '67 (no vapor capture) and my '85 with its vapor capture system mostly all there.

Somewhat related was what I thought was a veery interesting discovery was how much vapor even an open air cleaner captures when an engine is running at idle.
This is screenshot from a datalog where I removed the air cleaner lid while idling in the Summer.
Yellow markers on timeline are when the air cleaner lid was removed and then reinstalled.
View attachment 1715738435
Recording time in min:seconds along bottom.
There may have still been some winter fuel in the tank. I'd have to look to check that.



I think the reference is whatever the person writing about wants it to be, whether its the stuff out the vents or the stuff out thte tailpipe. Its all good discussion. :) But I too was focusing on tailpipe.


Looks like you're correct. The first generation of cats did reduce HCs as well as CO
View attachment 1715738438


There are two main groups that are (or were) lobbying for ethanol, and there may be others.
The automobile manufacture's were pushing for fuel changes that would help them meet both emissions and better corporate fuel milage overall. Do some web searching for Reformulated gasoline and ethanol and you'll find everythiung from academic papers to trade industry backed promotional/educational material.
Ethanol is an oxygenate and it can improve milage if the car is set up for it. I'll say this. This current generation of E10 RFG runs a heck of a lot better than the MTBE stuff we had for a few years. That stuff was horrible (and pretty toxic too).

According to the timeline, Calf banned MTBE in 2004, and the Federal oxygenate requirement was dropped in '06. The concept (as I understand it) was that the car companies only needed it for a few years to bridge the time needed to develop and produce slightly higher milage and lower emissions cars and trucks.
View attachment 1715738440
However at the same time the oxygenate was dropped, the "Renewable Fuels Standard" was implemented.
One perspective is the reason given on the timeline. Another is that the corn producers and industries that had grown to support the need for eth in fuel didn't want to see it go away.


Yea I agree. It seems kindof ridiculous how poor the fuel milage is on many vehicles today that have the benefit of more than 3 gears in the transmission. I think part of it is perceived safety and 'comforts' and all that stuff that adds weight.
Ironicly it seems to me behaviours have changed a lot too. I see a lot more people sitting in their cars with the engine idling than when I was kid. Now maybe its location not time related. Dunno. Just my observations.

Negative, ghostrider. That's hc measurement. Hydrocarbons. That's from burned fuel. There's no sniffer for unburned fuel.
 
Negative, ghostrider. That's hc measurement. Hydrocarbons. That's from burned fuel. There's no sniffer for unburned fuel.
That's what I was afraid you were saying.
Gasoline is hydrocarbons. I think we agree here.
Those that are used in the burning process with air become CO, CO2, NOx and sometimes water.
Any HC in the exhaust are left over fuel components. Are some transformed? Wouldn't surprise me. But for most of us we call it unburned fuel since they didn't completely react with the air.
 
That's what I was afraid you were saying.
Gasoline is hydrocarbons. I think we agree here.
Those that are used in the burning process with air become CO, CO2, NOx and sometimes water.
Any HC in the exhaust are left over fuel components. Are some transformed? Wouldn't surprise me. But for most of us we call it unburned fuel since they didn't completely react with the air.

No it's not. Not until it burns or evaporates. ......but yes, we do agree.
 
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