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I know this has been posted in other threads but I must say I never paid any attention to them. I used to buy from various stations in NJ, but the other day I decided to fill up with Shell v-power 93 in my W8. I can honestly say that there is a difference. Now I believe.. Amen

-MikedW8
 

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I've been using Shell for several years now. Ever since they started giving a 5% discount for using their credit card. At today's prices that's about 13 cents per gallon saved.
 

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I use either Shell V-Power (91 octane in CA) or Chevron Supreme (also 91), always from stations which do high-volume, high-turnover business.
 

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you got me thinking now//.........:hmmm:

does this 10% ethnol really mess up performance cause i read that most people look for the stations that dont have it in there premium gas ?
 

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you got me thinking now//.........:hmmm:

does this 10% ethnol really mess up performance cause i read that most people look for the stations that dont have it in there premium gas ?
I would like to know as well, I always use Sonoco Ultra 94 Octane here in Canada and they use 10% Ethanol but they have the higher octane rating... What is the consensus on ethanol?
 

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I would like to know as well, I always use Sonoco Ultra 94 Octane here in Canada and they use 10% Ethanol but they have the higher octane rating... What is the consensus on ethanol?
Even though Ethanol has higher octane content, the mpg that you get from ethanol is lower. I think if you were to use 100% ethanol your mpg would reduce by 20-25%. So my guess is you would loose about 2% mpg with 10% ethanol. If you car is giving you 20 mpg that is about 0.4 mpg loss with 10% ethanol.
 

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Even though Ethanol has higher octane content, the mpg that you get from ethanol is lower. I think if you were to use 100% ethanol your mpg would reduce by 20-25%. So my guess is you would loose about 2% mpg with 10% ethanol. If you car is giving you 20 mpg that is about 0.4 mpg loss with 10% ethanol.
So with the Octane rating on the gas at 94 and the 2% loss I should be breaking about even with a 93 Octane with no ethanol? Does that make sense? Thaks for the input! :thumbup:
 

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Heh. I fill up with gas from the supermarket. It has 10% ethanol in it. I still burn a tank every two weeks, so the higher octane of the ethanol is definitely letting me get better turbo compression without pinging.

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Ethanol has an octane equivalent rating of about 105. It doesn't actually contain octane, unlike gasoline, hence the "equivalent" rating. For the record, heptane, octane, and iso-octane are the bases for the octane scale, with heptane having a rating of 0, octane 50, and iso-octane 100.

All (pure) gasoline has the same potential energy; the octane rating only indicates whether the gasoline has a sufficiently-high spontaneous-combustion temperature and sufficiently-smooth burn pattern. However, since higher-octane gasoline has a higher spontaneous-combustion temperature, it can withstand higher compression without pre-igniting, and the higher compression allows the engine to convert a greater percentage of the gasoline's explosive force into torque instead of dissipating it as heat.

The ability of turbocharged engines to vary their compression ratios by adjusting the boost pressure from the turbocharger allows them to adapt to higher-octane, lower-energy fuels like E10 gasoline without losing gas mileage, as the higher flashpoint of the hybrid fuel allows for higher compression and higher energy efficiency. As demonstrated by Saab, even E85 gasoline can be burned by a turbocharged engine (with a properly-reprogrammed ECU) with even greater power AND mileage than pure gasoline.

Engines that don't get hot enough, or don't compress their A/F mixture enough to cause pinging will not see any benefit from higher-octane gasoline. That said, there are many shades of grey when it comes to pinging, as not every ping is a full pre-detonation, and as such some engines that run hotter than expected may still see some benefit from a higher-octane fuel than specified in the owner's manual.
 

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The ability of turbocharged engines to vary their compression ratios by adjusting the boost pressure from the turbocharger allows them to adapt to higher-octane, lower-energy fuels like E10 gasoline without losing gas mileage, as the higher flashpoint of the hybrid fuel allows for higher compression and higher energy efficiency.
Interesting, do you have anything to back this up? This is the first I've heard of anything like this. Not that I don't believe you, I'd just like some more information.
 

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i noticed that i did lose about 2-4 mpg.... and the funny thing is that my local BP was under renovation and as soon as it was back up it was the cheapest in the neighorhood but i relized that it says "10% ethnol" in the gas though .......
 

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Interesting, do you have anything to back this up? This is the first I've heard of anything like this. Not that I don't believe you, I'd just like some more information.
Unfortunately, I can't think of any specific references at the moment. I suspect, if you have doubts about whether it's accurate or not, those doubts stem from the fact that turbocharged engines achieve higher compression by forcing more air into the same space, rather than by forcing the same air into a smaller space.

Technically speaking, compression is compression and its effects (higher temperature and greater efficiency) are the same regardless of the source. However, in the first case (more air, same space), the engine does have to match the extra air with extra fuel. Obviously this increases fuel consumption, but because compression is also increased, the engine is able to make more power from that fuel than a non-turbocharged engine with the same air throughput would be able to make.

Since it takes the same amount of power to move the same car at the same speed, regardless of where that energy comes from, the net effect is that (surprise surprise!) a turbocharged engine will require less fuel to move the car at the same speed than a comparable N/A engine would -- or in the case of a high-octane, low-energy fuel like Ethanol, the turbocharged engine will be able to extract enough usable energy from the fuel (within reasonable limits, of course) to be able to maintain the same gas mileage, whereas a N/A engine would lose power (because it can't force itself to take in more A/F mixture) AND burn more fuel (because it can't increase its compression ratio to compensate).
 

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Unfortunately, I can't think of any specific references at the moment. I suspect, if you have doubts about whether it's accurate or not, those doubts stem from the fact that turbocharged engines achieve higher compression by forcing more air into the same space, rather than by forcing the same air into a smaller space.

Technically speaking, compression is compression and its effects (higher temperature and greater efficiency) are the same regardless of the source. However, in the first case (more air, same space), the engine does have to match the extra air with extra fuel. Obviously this increases fuel consumption, but because compression is also increased, the engine is able to make more power from that fuel than a non-turbocharged engine with the same air throughput would be able to make.

Since it takes the same amount of power to move the same car at the same speed, regardless of where that energy comes from, the net effect is that (surprise surprise!) a turbocharged engine will require less fuel to move the car at the same speed than a comparable N/A engine would -- or in the case of a high-octane, low-energy fuel like Ethanol, the turbocharged engine will be able to extract enough usable energy from the fuel (within reasonable limits, of course) to be able to maintain the same gas mileage, whereas a N/A engine would lose power (because it can't force itself to take in more A/F mixture) AND burn more fuel (because it can't increase its compression ratio to compensate).
Deusexaethera is right.
Fuel and heat = horsepower. Now compress more of this into the same space and presto, you’ve got more power. And yes a turbocharged or a supercharged car will produce more power much more efficiently than naturally aspirated engines. I have a supercharged Mercury Mystique that has an estimated 415hp and gas mileage went from 20mpg naturally aspirated to 22mpg supercharged.
 

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Interesting. I'd never thought about it in terms of ethanol in forced induction systems, just always was told and knew that because it has less power per amount of fuel that it would cause lower mileage. The variable amount of forced air to compensate for this, thus resulting in the same level of performance, makes sense.

A bit off topic, strangely enough this thread made me have a dream last night that I was driving around and stopped to get gas and realized that my regular station changed from 91 octane to 96 and kept the price the same. I was all happy in the dream about how happy my car would be. Woke up and realized 91/92 were really my only options here in Kansas :(
 

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I have had the exact opposite with shell V power. I filled up with about 7-8consecutive tanks. The car idled rough, I switched back to Mobile gas and car idled normal again, almost right away. VERY STRANGE
 

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I have had the exact opposite with shell V power. I filled up with about 7-8consecutive tanks. The car idled rough, I switched back to Mobile gas and car idled normal again, almost right away. VERY STRANGE
Yeah I noticed when I put in Mobil gas a couple times when I was up in Illinois over the summer (they don't have it down here) my car was super happy.
 

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Up here I find that Sunoco Ultra 94 is the stuff. Pioneer's 91 usually keeps her quite happy though(ontario only gas chain).

Usually I look for Shell when I'm south of the border, Chevron seems to be good too.
 
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