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

[Gumbo4x4]

Use of higher octane could be used to up fuel economy, but would probably increase the operating costs due to the price of high octane gas

 

[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.

It's illegal and has been since 1996 due to the Clean Air Act Amendments of 1990. Even in an older car with an engine designed for lead, it would be illegal with a fine of up to $25,000. Part (a) is about putting leaded fuel into a vehicle designed for unleaded only, but part (b) mandates that leaded fuel can't be used for on-street vehicles.

http://www.ecfr.gov/cgi-bin/text-id...8&view=text&node=40:17.0.1.1.9.2.47.2&idno=40

§ 80.22 Controls and prohibitions.

(a) After December 31, 1995, no person shall sell, offer for sale, supply, offer for supply, dispense, transport, or introduce into commerce gasoline represented to be unleaded gasoline unless such gasoline meets the defined requirements for unleaded gasoline in § 80.2(g); nor shall he dispense, or cause or allow the gasoline other than unleaded gasoline to be dispensed into any motor vehicle which is equipped with a gasoline tank filler inlet which is designed for the introduction of unleaded gasoline.

(b) After December 31, 1995, no person shall sell, offer for sale, supply, offer for supply, dispense, transport, or introduce into commerce for use as fuel in any motor vehicle (as defined in Section 216(2) of the Clean Air Act, 42 U.S.C. 7550(2)), any gasoline which is produced with the use of lead additives or which contains more than 0.05 gram of lead per gallon.

"Motor vehicle" is defined as anything for on-highway use. I assume that this would exempt track-only vehicles and of course aircraft.

http://www.law.cornell.edu/uscode/text/42/7550#2

(2) The term “motor vehicle” means any self-propelled vehicle designed for transporting persons or property on a street or highway.

 

[brerrabbit]

All fuels, race gasoline or otherwise all come from the same refineries, out of the same crack towers. The difference is in the blend after the refining process. There are several ways to get octanes higher. One is the use of naptha, another is with gas oil, while yet another is the injection of butane into the gas. For environmental reasons lower RVP gas is required by law during the summer. That way less vapors escape into the atmosphere. The way you lower the pressure is to take out the butane. All the butane that comes out of the gas stream in the summer is stored and then after September 15th when the RVP regulations are relaxed the butane can be reinjected into the gas as a cheap octane booster.

Another occurance in the gas industry is that refineries are making a lot of sub octane gas. They can do this because the 10% ethanol they blend with the gas raises the octane. So in the Pacific Northwest all the refineries there make 84.7 octane regular and 90 octane premium. They ship it to the terminal where it is blended with 10% ethanol and the octane is increased to 87 and 92. So a lot of octane now is actually generated by ethanol.

More and more refineries are making sub octane blends as we move to a total 10% ethanol world. Clear gas is getting harder and harder to find and the price is considerably higher.

 

[bcla]

All fuels, race gasoline or otherwise all come from the same refineries, out of the same crack towers. The difference is in the blend after the refining process. There are several ways to get octanes higher. One is the use of naptha, another is with gas oil, while yet another is the injection of butane into the gas. For environmental reasons lower RVP gas is required by law during the summer. That way less vapors escape into the atmosphere. The way you lower the pressure is to take out the butane. All the butane that comes out of the gas stream in the summer is stored and then after September 15th when the RVP regulations are relaxed the butane can be reinjected into the gas as a cheap octane booster.

Another occurance in the gas industry is that refineries are making a lot of sub octane gas. They can do this because the 10% ethanol they blend with the gas raises the octane. So in the Pacific Northwest all the refineries there make 84.7 octane regular and 90 octane premium. They ship it to the terminal where it is blended with 10% ethanol and the octane is increased to 87 and 92. So a lot of octane now is actually generated by ethanol.

More and more refineries are making sub octane blends as we move to a total 10% ethanol world. Clear gas is getting harder and harder to find and the price is considerably higher.

You forgot to mention tetraethyl lead. Not that it's legal or anything.

However, my understanding is that most gas streams are somewhat random in composition, but race fuels will be blended from almost pure hydrocarbons (which come from the refining process). And there's lot of toluene in race fuels, and it's my understanding that good deal comes extracted from coal when making coke.

The one issue that does concern me is that ethanol attracts water, and that enough water will lower the octane rating of the fuel. I remember checking my dad's lawn mower that wouldn't start, and there was considerable water in the tank.

 

[bcla]

I finally went to a place that sells these high octane fuels. The place had a single pump (both sides) that sold 87/94/96/98/100. It had a VP Racing Fuels sticker, and the company claims that the only street legal fuel it sells is 100 octane race gas. I'm guessing they get to those numbers by blending it either at the pump, in the tank, or in the tanker. The 100 octane was $7.69/gallon. I've seen another gas station that prominently sells VP Racing gas, and their super premium is 93 octane.

The 94 octane is pricey. If I needed 93 I'd probably just pump in a combination of 91 and 94 at a 1:2 ratio. The 94 octane I saw sold on the East Coast was cheap enough that I'd never bother.

 

[tvguy]

I think we need to be clear that while a car maker may recommend a higher grade of fuel, almost every car made since 1970 has been required to be able to safely run on regular grade gasoline. The law does make an exception. Car models that sell less than 500 vehicles a year, can require high grade fuel. and that tends to be your exotics like Maserati, Ferrari and Rolls Royce
And a quick check of Subaru Impreza WRX STi forums shows some owners use regular fuel (usually for around town driving), with a decline in performance, but no harm to the engine since the computer corrects automatically for octane level in the fuel.

 

[Squirlz]

I think we need to be clear that while a car maker may recommend a higher grade of fuel, almost every car made since 1970 has been required to be able to safely run on regular grade gasoline. The law does make an exception. Car models that sell less than 500 vehicles a year, can require high grade fuel. and that tends to be your exotics like Maserati, Ferrari and Rolls Royce
And a quick check of Subaru Impreza WRX STi forums shows some owners use regular fuel (usually for around town driving), with a decline in performance, but no harm to the engine since the computer corrects automatically for octane level in the fuel.

Yeah that's constantly being hashed over on my car forums. The consensus is why would you buy a performance car and then suffer worse fuel economy and performance to save a couple bucks? Penny wise, foot/pounds fuelish.

 

[FlightlessDuck]

Here in PA, I see a lot of stations that have 87, 89, and 93. Some have 87, 89, 91. Others have 87, 89, 91, and 93.

When we went out west this last month, I saw places where Regular was 85.

 

[bcla]

I think we need to be clear that while a car maker may recommend a higher grade of fuel, almost every car made since 1970 has been required to be able to safely run on regular grade gasoline. The law does make an exception. Car models that sell less than 500 vehicles a year, can require high grade fuel. and that tends to be your exotics like Maserati, Ferrari and Rolls Royce
And a quick check of Subaru Impreza WRX STi forums shows some owners use regular fuel (usually for around town driving), with a decline in performance, but no harm to the engine since the computer corrects automatically for octane level in the fuel.

Some **require** 91 AKI octane rated unleaded but are tuned for better performance with 93 AKI. As in can't retard the timing enough to prevent knock at wide open throttle. These are very higher performance cars like newer Corvettes, Porsches, Subaru WRX STi (the one I'm thinking of getting), Nissan GT-R, exotics, etc.

I've almost never been to a gas station that doesn't sell premium of some kind. I'm old enough to remember when leaded gas was the most common and 86 octane regular unleaded was the only unleaded sold at most gas stations. I've been to remote gas stations in the middle of Nowheresville where the pumps had 87 and 91 unleaded, including one place that only had two gravity feed pumps. The exception was another out of the way place in Giant Sequoia National Monument that only had 87 and 89 octane.

 

[Squirlz]

Some **require** 91 AKI octane rated unleaded but are tuned for better performance with 93 AKI. As in can't retard the timing enough to prevent knock at wide open throttle. These are very higher performance cars like newer Corvettes, Porsches, Subaru WRX STi (the one I'm thinking of getting), Nissan GT-R, exotics, etc.

I've almost never been to a gas station that doesn't sell premium of some kind. I'm old enough to remember when leaded gas was the most common and 86 octane regular unleaded was the only unleaded sold at most gas stations. I've been to remote gas stations in the middle of Nowheresville where the pumps had 87 and 91 unleaded, including one place that only had two gravity feed pumps. The exception was another out of the way place in Giant Sequoia National Monument that only had 87 and 89 octane.

A friend of mine just got the new STi

 

[bcla]

Yeah that's constantly being hashed over on my car forums. The consensus is why would you buy a performance car and then suffer worse fuel economy and performance to save a couple bucks? Penny wise, foot/pounds fuelish.

At the very least, why would anyone go that low with a vehicle that's designed for optimum performance with 93 octane.

My folks drive a Camry V6. Occasionally I've filled it up with premium because it can actually take advantage of it. However, my folks drive like grandma/grandpa (and they are) and are cheap. So they fill it up with 87 and are happy.

And as for all those different octane ratings and different flex-fuel ethanol/gasonline blends, there are blending fuel pumps. I understand a lot of mid-grade is blended at the pump. However, once I asked a fuel truck driver how he delivered mid-grade with only two tank trailers, and he showed me the seam where one tank had two compartments.

This article shows a pump that dispenses 87, 89, E30, and E85 via a blender pump:

http://www.afdc.energy.gov/technology_bulletin_0210.html

I suppose E30 might be useful for flex-fuel vehicles where the driver just wants a little bit more range on a tank.

And someone mentioned ethanol. I remember my first car purchased years ago said that up to 10% ethanol, 5% methanol (with corrosion inhibitors), or 15% MTBE was OK. Of course MTBE is gone from fuel and I haven't heard of methanol being used in a long, long time.

 

[Gumbo4x4]

Of course MTBE is gone from fuel and I haven't heard of methanol being used in a long, long time.

Not used for commercial fuel, but methanol is still very popular in race applications.

 

[Swissdog2010]

I have three different stations within a mile of my house that sell 93. A Sunoco, a Speedway and a Citgo. Works just fine in my 440.