Premium Fuel Recommendations

[hesster]

To complicate matters further, there is Summer and Winter Blends. My Whipple Blown ride was tuned specifically with Summer blended gas, and my tuner recommended to "take it easy" if I was running Winter Blends. I believe it is due to slightly more energy of the Summer Blends here in the Michigan.
Here are a few good articles explaining the blends:


"Lots of drivers out there probably didn't know (or care) that gasoline is blended differently for summer or winter. Recently, though, that issue has been capturing headlines, thanks to a showdown in California, where Gov. Jerry Brown wants to allow the early use of the so-called winter-blend gas in a play to bring down spiking gas prices in the Golden State.

The price of gas is a confusing, convoluted issue. But before we get into that, what exactly is the difference between summer and winter gas, anyway? Basically, winter gas is cheaper but not as pure, and worse for the environment.

The nation has some 20 different blends of gasoline to meet overlapping state and federal guidelines. The reason for the different grades of gas comes down to trying to control VOCs (volatile organic compounds) that are more likely to evaporate the hotter it gets. More VOCs equal more smog, especially in summer, when the heat in the atmosphere increases the propensity for atmospheric ozone and adding in the VOCs increases the intensity of the smog.

The different grades of gas are measured on a system of RVP, or Reid Vapor Pressure, which is measured in pounds per square inch (PSI). The higher the RVP number of a particular gas blend, the easier it is to vaporize and the worse it is for the environment. All gasoline blends have to be below 14.7 PSI, which is normal average atmospheric pressure. Any number higher than that and gasoline would become a gas.

During the summer heat, the RVP of gas has to be especially low to keep it from boiling off. The EPA mandates an RVP maximum of anywhere between 9.0 PSI and 7.8 PSI for summer-grade fuel, depending on region (though you get a fudge factor of 1 psi for using gas blended with 10 percent ethanol). There are even lower RVP-rated fuels for cities like Houston, New York, and L.A. Different states and cities have their own rules based upon their seasonal temperatures—Washington state needs different summer gas than, say, Florida. That's why there are so many blends. To make it more complicated, the time for switching from summer- to winter-blend gasoline varies by state too.

Generally, the lower the RVP of a gas blend, the more it costs. For example, in winter you can blend butane, which is relatively plentiful and cheap, with gasoline. But butane, which has an RVP of 52 on its own, can't be used in summer, when it would immediately boil off as a gas. So "purer" summer gasoline is by default costlier. (And there are other factors at play too. More people travel in summer during peak driving season, for instance, putting more stress on demand.)

Back to California's woes: First, an August fire at a Chevron refinery diminished the ability of the oil industry to meet demand, driving up delivery times and transportation costs. That especially hurts in California, which has stricter standards than anywhere else in the nation as far as what blends it will sell, making the state especially vulnerable to supply issues.

So Brown's loosening of the rules on gas blends is an attempt to fight back against that vulnerability and bring prices back down. But there's no guarantee. Gasoline is a commodity, and yet the price-setting system has only a loose relationship to supply and demand. Rather than having an independent governing body oversee the supply side of the equation, suppliers voluntarily report on the supply of oil. And any time the numbers could be fudged for profit, we ought to raise our eyebrows."

"The higher the RVP, the more pressurized, and thus volatile, the gasoline. The lower the RVP, the more pure the gasoline, meaning it will take extra heat and energy to cause gas to evaporate.

In the summer, when temperatures are hotter and liquids evaporate easier, gasoline is made with a lower RVP in order to prevent the gas from evaporating, becoming useless for your vehicle. Not only is evaporated gas not useful for your car, it pollutes the air and adds to city smog. However, there is a price to pay for this gasoline—literally. Summer blend gasoline is more difficult to produce than winter blend gasoline, which is why gas prices tend to rise along with the temperatures.

In terms of gas mileage, you get better mileage on summer blends than winter blends because the summer blend gasoline has about 2% greater energy value than winter blend. So the gas you are using now most likely has a lower energy value than the gas you used in the winter. That means a little bit lower mileage for you until the spring time, when they will reintroduce summer blend gasoline. And this is beyond mileage loss you see with ethanol being blended into both summer and winter fuels. Cars, trucks, boats and small engines, all will see the difference in mileage and fuel consumption between the seasons. "

[morrow052]

There's a newly built Shell station down the road from me, V-Power Nitro + , It's the only place I go for gas lol unless I'm traveling, then I'll just pick a top tier place, I only go to Exxon or Shell (personal preference) I will drive around and around until I find a Shell or Exxon

[DvKillar]

good catch, Hester!

[TheInfamouSS]

I may or may not have been employed, or am currently employed at a Costco, but I do know that the one close to my house, and the ones in the surrounding area are very particular in making sure that all the tanks and pumps are cleaned on a regular basis. Probably more than necessary. They hold very high standards in my area when it comes to the Tire Shop and the Gas Station, and it is continuously being maintained by the workers, supervisors, and higher managers making frequent inspections. I can't speak for other areas, so results may vary, but it should be a company wide thing. We know there are always the 1 or 2 locations in any franchise that probably slip through the cracks and give everything a bad name, but I can only speak from my experience.

[Rock-It Man]

My main criterion for buying premium gas is whether anyone buys the premium at a particular station.

So I don't buy gas at big box stores, obviously.

[SSEssence]

I'm a Shell or Chevron man myself

[Wizard1183]

Shell Exxon or chevron only

[samman11]

I have been told to use only Ethanol-free gas for the best protection and performance. Here's a link to find those gas stations

https://www.pure-gas.org/

[JLSuperfly]

I always use Shell mainly because it is the closest where I live.

[Indydriver]

Originally Posted by Rock-It Man

My main criterion for buying premium gas is whether anyone buys the premium at a particular station.

So I don't buy gas at big box stores, obviously.

Costco sells beaucoup premium gas. It's turnover is probably greater than any single standalone gas station. A Costco gas station employee once told me they take Six truckloads per day. When I fill up my modified SS with premium (or Mr turbo Mazda prior to that) there are always high end cars requiring premium fuel filling up. I've never had a problem with any Costco fuel, regular or premium. Add in competitive pricing at the pump plus a 4% rebate on their Visa card and it's a no brainer. So your "opinion" based on no facts whatsoever, holds no weight with anyone who has real world experience.

[meadowz06]

I only use Exxon, Chevron, or Shell.

[Try2kpup]

I run 91 from the local Conoco-phillips station but it is non-oxygenated.
I run this in my 56 chevy exclusively so it has just become habit to put it in the 45th SS. Never had an issue in either car.

[ron123]

Originally Posted by ron123

BINGO on above post by Wally
Worked at a service station in high school that sold no-brand discount priced fuel. Often talked with different tanker delivery drivers. They all told me they deliver to some of the same national brand stations in that area (Texaco, Sunoco, Mobil). When it was a Mobil delivery the fuel picked up at the depot was the same except a small jug of "detergent" was poured in that compartment in the tanker truck ... magically turning it in to Mobil "Detergent" gasoline.

At the time I did a calculation of percentage of the "detergent" in that compartment and it was laughable. Since then, in the past 40+ years I've always used the cheapest priced gas for octane level my cars needed. I'm also an oil company stock holder in some of the national chain stations so I hope many continue to believe their commercials on their "superior" fuels ;-)

History Channel documentary covers this subject ... To follow-up, look at the ~30:00 minute mark in this History Channel video.
95% of fuel distributed is shared/common fuel from the refineries. Sometimes with a little container dumped in at the tanker terminal before delivery to "put a tiger in your tank", lol.
This video confirms my original post/experiences reported from when I worked in a service station back in HS.
Ron

[partlowr]

I don't know about some of the other gasoline brands being discussed in this thread but I can tell you for a fact that Shell premium burns cleaner than Mobile premium. One of my job perks is that my company pays for my fuel. For several years they only gave me a Shell credit card but then a few years ago they gave me a Mobil as well card so I now have both. Once I started running the Mobile premium 93 octane I started to notice accumulations of black carbon soot buildup around my exhaust pipes on all 3 of my cars. I didn't put 2 and 2 together right away but when it struck me I conducted a test. I polished up my exhaust tips on all three of my cars and ran only Shell premium in them for a couple of tanks, sure enough my exhaust tips where clean and bright after burning through a couple tanks. Then I fueled up with some Mobile premium in all three cars, sure enough I started seeing carbon soot buildup on all three exhaust tips within 100 miles or so. I don't notice any real fuel economy differences between the two but it has to make you wonder if I am seeing that much soot on my tips what is it doing to the rest of my engine and emissions system???? needless to say I now try to run Shell premium whenever possible.

I am not sure if the Mobile fuel is "dirtier" or if there is something in the fuel that is possibly making my computer/ECU fuel mapping making the car run rich would result in carbon build up in the exhaust????