When I was in high school I remember the mid and high grades of gas were incrementally 10 cents more than the grade below.

But now I see sometimes it's much more than that.

Just noticed it but thought maybe someone here might know why

#ManTuna

Well gas was most likely cheaper and therefore the $0.10 difference in price percentage was is most likely very close to what it is today. What I am saying is when gas was $1.50/gal for regular gas with a 6.5% premium for the next grade is $0.10. Today a 6.5% premium on $3.00/gal gas is approx. $0.20.

It hasn't been a dime apart in grades in about 15 years (pretty much around the time-frame of Katrina).

VaHunter, the spread between regular and premium isn't 20 cents like it used to be, but rather 70-80 cents higher than regular.

I was only using costs of gas and cost of difference between grades as an example of the difference, given that that is not the total reason for increases.

As for the difference between regular and premium in my area it is averaging around $0.37/gal. I am glad I do not live in Connecticut.

The only thing I run premium in is the bike - all else gets the cheap stuff.

Just a guess, but I heard long ago that one reason gas in Kali is so high is they have to shut down and re-whatever to produce it instead of the standard blends. Might have something to do with a similar production process. Economy of scale means lower cost, and the opposite results from limited production. Haven’t used premium since the 70s, except what I bought after the pipeline hack, when it was all they had.

When I purchase my 2002 Ford Super duty diesel fuel was $0.25/gal cheaper than gasoline and I was still unable to justify the added cost of $4200.00 for the diesel motor so I purchased the gaser and I am glad I did. Shortly after the purchase diesel fuel started its climb up in cost.

Today diesel is around $0.80/gal more, in my area, than gasoline and a diesel motor is approximately an $8000.00 option.

Cause they can

Interesting. Most premium is higher in alcohol. I want to run regular! No corn involved! And I always thought diesel would be cheaper than gas because it was a biproduct of making gasoline. What is going on here? Be Well, RZ.

Wouldn't the reduced energy content of regular gas with ethanol make the difference between it and alcohol free premium about a wash?

Maybe its more expensive to run the cheep stuff.

At one time diesel was always cheaper than regular. 2001 when I bought my F250 it was $1.19 a gallon and regular something like $1.35.

Here, premium is the only way you can run WITHOUT the ethanol.

Don't know where you get "byproduct". I was a pipeline pump (800 hp stationary diesel engines) station operator for a couple years, one pipeline, several products, no pig between products, we would push one product with another. A petroleum lab guy was always on scene, and he would sample the product in the line and when the specific gravity (API gravity) got to a certain predetermined number, he would tell us and we would switch valves to divert the "new" product to the proper storage tank. In descending order of purity, Jet A and JP-4, diesel, Kerosene, #2 fuel burner oil, Avgas 115/145, and lastly gasoline 85. So diesel has the 2nd narrowest window of API gravity, hardly a byproduct.

Why is gas 10-15 cents a gallon more in Franklin TN, that Spring Hill just down the road?
Cause they can charge more and still sell it.

Democrats decided that the sulfur had to be removed from diesel before refiners could sell it. That is an expensive (and useless) procedure.

So there isn't really a solid reason that it used to be a set amount to increase from 94 to 96 for instance? Used to be 10 cents. Now it's whatever they feel like?

Another way to look at things is, a 2002 Ford powerstroke diesel is worth 3 times the money that your gas truck is right now.

The refining industry is still mostly geared toward producing regular-grade gas, leading to a shortage of both high-octane blendstock and alkylate, an octane booster. Premium gasoline is obviously a higher margin product, but it's much more expensive to make as well.

Because the market would bear it, maybe?

How much was unleaded Boomer?