A couple years ago I read in Sport Compact Car magazine that the least expensive blend of additives which make higher octane gas was patended by one company (don't remember which) and they were in the process of denying anyone else in the US from using their blend. As a result, lower octane gas, starting in states like California, was going to spread across the country until the highest anyone could get would be 91 AKI. I had pretended it wasn't true, that they were full of crap, but at a Mobil gas station in Vermont I saw their three grades 87, 89, and 93, with new AKI rating stickers essentially dropping them all one point each (I can't recall if regular, 87, was dropped to 86, but 93 and 89 both were down one number). Anyone have any insight on this subject?
falling Octane (AKI) ratings
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Around where I live, Mobil's fuel grades are presently 87, 88, and 92 and dropped 10 cents each per gallon. I mentioned this a few weeks ago on another thread not knowing if was relavent to the topic posted or not concerning fuels.
Patents...go figure. Money, money, money...
Patents...go figure. Money, money, money...
Highest octane fuel we can get in atlantic Canada is 91. Regular is 87, midgrade is 89.
94 In PA. All I pump.
87 - 89 - 91&92 here in wash state
93 in IL and that should be stay do-able as we're also 10% ethenol.
no fed.reg. here.87 and 91 I could live with here in ca.if only the refiners would cut the crap and remove this mid-grade(89) from the ranks.arco started this fiasco although there is no mandate.89 octane,lets see premium then regular;how hard is that!the oil co's all know what inelastic demand means. just raise the price if were going to get @#$%&*(gouged). no other options,consumers will pay.
Mid-grade gasoline is formed by blending regular and premium fuels at the pump. At least in California, refiners don't actually produce mid-grade gasolines.
91 octane (as opposed to what was formerly 92) gasoline here is a result of the reduction of MTBE in fuels. MTBE is an octane enhancer, and will eventually be replaced by some other oxygenate. MTBE is bad stuff once it gets into groundwater due to high rates of migration, and there have been any number of municipal water systems affected by it.
91 octane (as opposed to what was formerly 92) gasoline here is a result of the reduction of MTBE in fuels. MTBE is an octane enhancer, and will eventually be replaced by some other oxygenate. MTBE is bad stuff once it gets into groundwater due to high rates of migration, and there have been any number of municipal water systems affected by it.
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As far as I know we do not have any MTBE in the local gas anymore. At least a few large chains advertised prominently the lack of MTBE when MTBE was phased out during the past few years. Due to the groundwater issue, which you mention, the fuel tanks at a large number of gas stations where replaced.
Even during the time MTBE was in the gas, 91 Octane was the highest octane fuel to be found here, so I don't think there is a connection between MTBE and the 91 Octane gas.
93 and 94 still available in CT.
I was at a Citgo once (with a friend, for the diesel) and I saw the following selection buttons on the gasoline pumps:
87, 88, 89, 91, 93
I was like
I was at a Citgo once (with a friend, for the diesel) and I saw the following selection buttons on the gasoline pumps:
87, 88, 89, 91, 93
I was like
There are several ways to raise octane, MTBE is but one. MTBE was used due to it providing less AIR polution and is still a very good means of doing that. However the groundwater contamination issue pretty much killed it.
Somehow fixing the REAL problem (leaking tanks) was ignored....why scream at the 100,000 voting station owners in your own state when you can point at the Big Bad Out of State Corporation who makes MTBE?
Anyway, other additives are now used to get the same octane, it's just they pollute the air more than MTBE. And they typically cost more until the volumes get up to par.
Somehow fixing the REAL problem (leaking tanks) was ignored....why scream at the 100,000 voting station owners in your own state when you can point at the Big Bad Out of State Corporation who makes MTBE?
Anyway, other additives are now used to get the same octane, it's just they pollute the air more than MTBE. And they typically cost more until the volumes get up to par.
Hi Guy`s,
I have seen it as low as 85 at some no name stations out in Arizona some years back.I just noticed last montn the local sunoco dosn`t pump 94 anymore its 93 as there highest grade.
Riflemen10x
I have seen it as low as 85 at some no name stations out in Arizona some years back.I just noticed last montn the local sunoco dosn`t pump 94 anymore its 93 as there highest grade.
Riflemen10x
You'll find that the "regular" gas in the intermountain West is 85 octane. Mid-grade is 87, and premium is 91 (sometimes 90 in UT at least). It seems to be a function of altitude. I wonder if 85 octane at 4000 feet is equivalent to 87 octane at 2000 feet(?). Every car I've had will run fine on the 85 when I go through that way.
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With only 91 Octane Premium gas available at sea level, I'm stuck with using the bare minimum of what's specified for my engine.
The higher the altitude, the lower the effective compression ratio for N/a engines. 85 at higher altitude, has the same anti-knock properties as 87 at sea level in an N/A engine.
It was a few years back, but I once asked a tanker driver dropping a fuel supply off at a gas station about his tanks. I specifically asked how they got mid-grade. I only noticed two trailer tanks. He told me that a mix was possible, but that one of his trailers had a full single tank of regular, and the other had two compartments containing premium and mid grades.
Some of the companies making trailers can custom build for compartment size. The following shows a custom compartment size. You can see the line where a compartment was welded to the rest of the tank.
http://www.beallcorp.com/newtrucks/014.html
Some gasoline suppliers advertise a boosted detergent level for their premium grade. Even if they don't specifically refine a mid-grade, I'd think that they might want to blend the entire thing at the refinery for quality control.
A Subaru Impreza WRX STi requires 93 octane (R+M)/2 fuel. Where to find the stuff in California is a mystery to me. I guess one could find racing fuel near a race track or drag strip, but 100+ octane racing gas may be on the expensive side.
Agreed, and running octane boost with every tank can get pricey as well.
Some octane boosters can foul O2 sensors. I shy away from them, though I've seen good dyno results with Torco octane boost on heavily modded/boosted Ford modular motors.
Some octane boosters can foul O2 sensors. I shy away from them, though I've seen good dyno results with Torco octane boost on heavily modded/boosted Ford modular motors.
The hilarious thing about the octane boosters is the definition of an "octane point" (hint: it's not the same as the pump octane number). I picked up a bottle of Prestone "0 to 60 Booster", which claims to raise the octane rating by up to 10 points. Of course one needs to read the fine print at the bottom of the label:
1 octane point = 0.1 octane number
So the kid thinking that he's turned 15 gallons of 87 octane regular into maybe 96-97 octane superfuel instead has turned it into (at best) 88 octane unleaded. And at the bargain price of $5. OTOH - a full tank of 91 octane fuel would just be an additional $3.
Back when Unocal still produced 76 gasoline (late 80's), they were selling 89 octane unleaded at the same price as other name brand regular unleaded.
BTW - looking up the Torco stuff seems to indicate that it's just a high octane gasoline. I'm a bit skeptical that it can really raise the octane rating as much as they claim.
Here's the 104+ FAQ entry on fuel grade:
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