How common is super premium (93+ octane) fuel?

[bcla]

I've been thinking of getting a car where 93 (R+M)/2 octane unleaded is recommended. I know I can find it at some specialty gas stations nearby, but it's something like $1.50/gallon more than 91 octane premium, which is the standard here in California (used to be 92 octane). Some have even taken to buying 100 octane street legal racing fuel and blending it with 91 octane premium unleaded to get around 93 octane. It won't be cheap though, and a bit difficult to properly get the mix just right just pumping into the car; I'd guess it works better blended precisely in large gas cans.

Now I won't get deep into the reasons why we don't commonly have 92 octane gas here in California or sell 93/94 much. It's basically the high demand for premium because of all the European cars as well as many of the high performance cars with relatively small engines. There's not necessarily enough high octane base fuel to go around, and 91 is the bare minimum for most cars that use premium unleaded. We also have a specific blend requirement in California and we can't import fuel from out of state that doesn't meet the California reformulated fuel requirements.

When I was in the suburbs of Philly earlier this year, I saw that every Sunoco station sold 94 octane, and I think most Chevron stations. I noticed the same thing on vacation in Florida a few years back. Around where I live there are a reasonably high number of cars that (more or less) require 93 octane - newer Porsches, Subaru WRX STi, and exotics. I'm not sure there's a lot of demand, but it's available and not selling at a huge premium.

So - it's weird here in California - almost backwards of what would make sense. We have a lot of cars that could use this stuff and a lack of places that sell it.

 

[FireDancer]

It isn't that hard to find 94 octane here (NE Ohio) if you need it. California has stricter emissions laws than other states and I thought had more rigid laws about fuel too so that might be part of the problem.

 

[Gumbo4x4]

93 is common here. 91 is tops I usually see any time I go West. We did have a station selling 100 at the pump, but too many people pumped it by accident and they put a lock on the pump. That made it a pain, demand dropped, and they quit selling it.

 

[bcla]

It isn't that hard to find 94 octane here (NE Ohio) if you need it. California has stricter emissions laws than other states and I thought had more rigid laws about fuel too so that might be part of the problem.

My dad used to drive a diesel car. I remember way back then, you couldn't find diesel #2 at every neighborhood gas station, but there were enough that you knew where to go that was within a reasonable distance. I remember being driven through the suburbs of Philadelphia and noticing that there were enough places selling the super premium that I could probably stand a reasonable chance of finding some in any town without have to do any advanced research (kind of like looking for places to charge an electric vehicle).

Around where I live I know where there's biodiesel and/or E85, but 93 or higher octane unleaded is rather hard to come by. I also see a lot of cars on the road that are supposed to use it.

If I decided to get that 2015 Subaru WRX STi that recommends 93, I would have to research where to buy the right fuel. I know I could get away with using 91 octane from pretty much any gas station, but I'd prefer to find the correct fuel.

Someone had a mapping project where places selling higher octane fuel are located. A lot of it was 100 octane street legal racing fuel, but others were selling straight 93 octane. I haven't heard of 94 octane sold in California like in other states.

https://maps.google.com/maps/ms?msi...l=37.538044,-122.183075&spn=0.657724,1.349945

 

[bcla]

93 is common here. 91 is tops I usually see any time I go West. We did have a station selling 100 at the pump, but too many people pumped it by accident and they put a lock on the pump. That made it a pain, demand dropped, and they quit selling it.

I've heard of certain 100 octane street legal racing fuels. At least one seller (Unocal/Tosco/Phillips/ConocoPhillips through various acqusitions) dyes their 100 octane blue and a common nickname for it is "Smurf gas". They typically have their own nozzles rather than sharing the same nozzle for different grades. I've spilled a little gas before, and it feels kind of oily. The description I've heard of this racing fuel was that it was more like a solvent - maybe this cool feeling like if you've ever spilled acetone on your hands and it evaporates cleanly.

This one is almost scary looking. I'm not even sure if some of these are legal unless used only on the track.

 

[Gumbo4x4]

It's only illegal if they don't charge the highway tax. That's another reason so many guys get their race fuel away from the pumps - lower cost. I used to run 108 leaded in my Jeep and yeah, it was very different from pump gas. For starters, it was purple, and it gave off a whole different odor through the exhaust.

 

[bcla]

It's only illegal if they don't charge the highway tax. That's another reason so many guys get their race fuel away from the pumps - lower cost. I used to run 108 leaded in my Jeep and yeah, it was very different from pump gas. For starters, it was purple, and it gave off a whole different odor through the exhaust.

As you hinted, some racing fuels are leaded and that's definitely illegal on the street. Sunoco has a bunch of different racing fuels, and each one is apparently dyed a different color.

I've asked what a certain steam railway uses for their oil-burning locomotives. I was told "#2 fuel oil". I asked what it was, and was told it's more or less #2 diesel that's been dyed (to make it identifiable) and only legal for use off the street since it's not subject to highway fuel taxes. It may also not be the low-sulfur fuel required to be sold at the pump these days. We don't have a whole lot of oil heating going on in California, so I'm not sure where they get the stuff. The vast majority of homes use natural gas heating.

 

[Squirlz]

I have 3 cars that need 91+ and I always run 93 or 94. Never have any problem finding it, but I've never driven in California. I've run 100 in my MINI on track days. Came from a pump at the track.

 

[Gumbo4x4]

Actually, leaded gas is still legal, but it will burn up your cat if you have a modern car.

#2 diesel is the on road version. #1 is for farm/off highway use. Same fuel minus the dye and the taxes.

 

[bcla]

Actually, leaded gas is still legal, but it will burn up your cat if you have a modern car.

#2 diesel is the on road version. #1 is for farm/off highway use. Same fuel minus the dye and the taxes.

That's not what I remember from reading the owner's manual for my dad's car. It stated that #1 diesel was suitable for lower temperatures because it gelled at lower temps than #2. It also stated that in place of #1 diesel, that kerosene could be added to help operate in lower temperatures. I have never seen #1 diesel for sale at a gas station though. The manual was written in the 80s, so maybe something has changed since then.

http://www.dummies.com/how-to/content/understanding-diesel-fuels.html

 

[brerrabbit]

I work for a major oil company in the retail fuels division. ULSD Ultra Low Sulfur Diesel is required by law in the US. It is also referred to as ULSD #2. ULSD #1 is actually closer to kerosene and is for cold climates and winter use. When ULSD is used for off road purposes, ATV's boats, farm equipment, etc then a red dye is introduced to the fuel and there are no fuels (road use) tax collected.

The idea that you must have 93 octane fuel is not always correct. The owners manual of many of these vehicles call for premium fuel but many times do not denote the octane. Some may but most don't. Also remember that the introduction of 10% ethanol raises the octane of the fuel by two points, so if a fuel is listed as 93 octane with ethanol, it is base premium 91 made a 93 with the introduction of ethanol. Many racing fuels are actually higher ethanol blends. They take 91 octane fuel and add up to 30% ethanol to get the higher octane.

 

[EMAW_KSU]

Actually, leaded gas is still legal, but it will burn up your cat if you have a modern car.

#2 diesel is the on road version. #1 is for farm/off highway use. Same fuel minus the dye and the taxes.

The difference between #1 and #2 is the gel point.

 

[bcla]

The idea that you must have 93 octane fuel is not always correct. The owners manual of many of these vehicles call for premium fuel but many times do not denote the octane. Some may but most don't. Also remember that the introduction of 10% ethanol raises the octane of the fuel by two points, so if a fuel is listed as 93 octane with ethanol, it is base premium 91 made a 93 with the introduction of ethanol. Many racing fuels are actually higher ethanol blends. They take 91 octane fuel and add up to 30% ethanol to get the higher octane.

I was thinking of some very specific high performance cars. The Subaru Impreza WRX STi is well known as one with a 93 octane requirement. They typically say 91 is OK with a resulting decrease in performance (timing will be retarded to prevent detonation), but 93 is ideal. I understand that some exotics can actually take full advantage of 100 octane racing fuels, although many of the cars that absolutely should have them have been modified.

And I don't know of any street fuels sold as gasoline that has more than 10% ethanol where I live. I've heard of some push for E15, but some manufacturers specifically warn against it. I know part of getting to 93 octane is using oxygenates like ethanol with inherently higher octane rating, but they mostly need to use higher octane gasoline to get up to 93 AKI octane .

http://www.subaru.com/vehicles/impreza-wrx/models-specs.html

Fuel requirement: Premium unleaded gasoline (91 octane)
Premium unleaded gasoline (91 octane) required. 93 octane recommended (WRX STI).

Same for most Porsche models. The fuel requirement for the Cayman is on P 196.

http://www.porsche.com/all/media/pdf/Owners_Manual_Cayman_PCNA.pdf

Fuel Recommendations

Your Porsche is equipped with catalytic converters and must use UNLEADED FUEL ONLY

Your engine is designed to provide optimum performance and fuel economy using unleaded premium fuel with an octane rating of 98 RON (93 CLC or AKI)

Porsche therefore recommends the use of these fuels in your vehicle. Porsche also recognizes that these fuels may not always be available. Be assured that your vehicle will operate properly on unleaded premium fuels with octane numbers of at least 95 RON (90 CLC or AKI), since the engine’s “Electronic Oktane™ knock control” will adapt the ignition timing, if necessary.

Maybe the Nissan GT-R (P 9-4):

https://owners.nissanusa.com/content/techpub/ManualsAndGuides/GTR/2013/2013-GTR-owner-manual.pdf

FUEL RECOMMENDATION

VR38 engine
Use unleaded premium gasoline with an octane rating of at least 93 AKI (Anti-Knock Index) number (Research octane number 98) to maximize vehicle performance. If the premium gasoline specified above is not available, you may use unleaded premium gasoline with an octane rating of at least 91 AKI number (Research octane number 96), but you may notice a decrease in performance. Do not use gasoline with an octane rating lower than 91 AKI (Research octane number 96).

. Do not use E-15 or E-85 fuel in your vehicle. Your vehicle is not designed to run on E-15 or E-85 fuel. Using E-15 or E-85 fuel in a vehicle not specifically designed for E-15 or E-85 fuel can adversely affect the emission control devices and systems of the vehicle. Damage caused by such fuel is not covered by the NISSAN new vehicle limited warranty.

The most interesting discussion is when the standards (RON, MON, (R+M)/2 [also known as anti-knock index]) aren't specified. Europeans only see RON on their fuel pumps.

Most of the cars that can take advantage of 93 octane are sort of pipe dreams for me, although I could see buying a WRX STi (if my wife doesn't freak out). The GT-R and a new Porsche are a bit out of my price range, but I can dream about coming into a lot of money.

 

[Gumbo4x4]

And I don't know of any street fuels sold as gasoline that has more than 10% ethanol where I live. I've heard of some push for E15, but some manufacturers specifically warn against it. I know part of getting to 93 octane is using oxygenates like ethanol with inherently higher octane rating, but they mostly need to use higher octane gasoline to get up to 93 AKI octane .

We can buy E85 here.

Note that while higher in octane, methanol and ethanol produce less energy than gasoline. So, you'll typically burn more of it.

 

[bcla]

We can buy E85 here.

Note that while higher in octane, methanol and ethanol produce less energy than gasoline. So, you'll typically burn more of it.

Of course I said "sold as gasoline". Where E15 is sold, they do so with the implication that it's suitable for unmodified gasoline engines. A lot of automakers don't see it that way.

While E85 does have less energy content than E10 sold as gasoline, the amount of fuel required isn't directly proportional to the energy content. These guys got about 74% of the mileage running E85 compared to standard 87 octane gas, where E85 has less than 70% of the energy content:

http://www.edmunds.com/fuel-economy/e85-vs-gasoline-comparison-test.html

Part of is is that with such high ethanol, the octane rating is considerably higher because of the anti-knock properties. The engines are designed to advance the timing and are more efficient as a result. Some engines could be tuned for better mileage running 100 octane race gas, but I can't imagine that getting better numbers would offset the shock of asking people to pay twice as much for gas.

Still - I know a couple of places that sell E85, and the prices don't seem as if it would be worth running it even with a flex fuel vehicle.

 

[Gumbo4x4]

It definitely doesn't work out when the price is close. When it gaps to 75 cents or more, it becomes more interesting.

The reason I bring it up though is you can blend E85 with straight 91 octane for a cheap octane boost

That said, my friends who use E85 as race fuel all say that the stuff from the pump is highly inconsistent with as little as 70 percent ethanol at times.

 

[brerrabbit]

The governments definition of E-85 is any fuel blended with more than 50% ethanol. Also there are state and federal mandates of the RVP (Reed Vapor Pressure) of fuel that must be met and ethanol raises RVP so at certain tines of the year they must use less ethanol to meet the standard.

 

[bcla]

The governments definition of E-85 is any fuel blended with more than 50% ethanol. Also there are state and federal mandates of the RVP (Reed Vapor Pressure) of fuel that must be met and ethanol raises RVP so at certain tines of the year they must use less ethanol to meet the standard.

I was under the impression that more gasoline in the blend would result in better fuel economy because of the higher energy content. I heard that E85 is theoretically 103 octane, but in flex fuel engines it doesn't necessarily translate to better performance.

 

[Gumbo4x4]

I was under the impression that more gasoline in the blend would result in better fuel economy because of the higher energy content. I heard that E85 is theoretically 103 octane, but in flex fuel engines it doesn't necessarily translate to better performance.

It does. I'm not sure how much you'd notice the difference in E70 vs E85 though.

More octane in & of itself doen't automatically mean better performance. If your car is tuned to run on 93, 103 won't make it run better.

That said, race gas is generally of better quality & consistency than pump gas. And some performance engines are more finicky than others.

 

[bcla]

It does. I'm not sure how much you'd notice the difference in E70 vs E85 though.

More octane in & of itself doen't automatically mean better performance. If your car is tuned to run on 93, 103 won't make it run better.

That said, race gas is generally of better quality & consistency than pump gas. And some performance engines are more finicky than others.

I was thinking of a vehicle that is designed to use up to E85. And of course because they have to contend with varying proportions of ethanol and gasoline, they are constantly adjusting. However, in order to make E85 pay off, they have to be able to advance the timing to make up for the lower energy content.

I'm also pretty sure that major automakers could probably extract 5 MPG more out of their highest mileage cars by tuning them for 100 octane race gas. Of course they won't, because the assumption of most people buying an "economy car" is that they should be able to run it on 87 octane unleaded. Even so, carmakers have gotten extreme in recent years, with some moving to require 5W-20 motor oil and even 0W-20 motor oil in order to extract every last bit of fuel economy out of the cars, but short of requiring them to use 91 octane fuel.

Also - my understanding is that race gas isn't made using the same refinery "streams" that are used for the common fuels sold at most gas stations. They'll have output streams that result in various amounts of 83/85/89/93/95/97 octane fuel and then blend it (along with oxygenates) to get whatever is sold at the pump. It's supposed to be a balancing act of supply and demand that determines what is done. It's commonly 87/89/91 in California, although it used to be 87/89/92. However, we've got a lot of cars that require at least 91 in California. In order to meet the demand as well as use up the low octane streams, 91 is now the standard for premium. I understand that in places with lower demand for premium (especially with lots of pickup trucks) and where gasoline can be freely pipelined between states, 92 is often still the standard, and 94 is available. Some places it's 91 for premium and 93 is pretty common.

I heard that something like 100 octane racing fuel is mostly blended from pure hydrocarbons rather than the typical somewhat random hydrocarbon composition of refinery fuel, and the price reflects that. I read a list of the components of typical 100 octane racing fuel - isooctane, toluene, xylene, and isobutane. Sounds a lot like the stuff that goes into my backpacking stove gas canisters (at least the isobutane). I also understand that race fuel is typically more volatile than ordinary pump gas and this may be important for performance with certain high revving engines, where poor vaporization may hurt performance.