Gas regular or premium???

[Jimmmmbo!]

Wally - I'm in Prior Lake and have been using either Shell no-corn 91 from the downtown Shakopee MN station or Fleet Farm no-corn 92 in Lakeville with similar mileage improvement. It's even helpful to go puregas every other fill-up.

Legally, you're not supposed to do that in MN. Are the gas station operators really that clueless that they don't see you putting the no-corn stuff in your newer cars?

Minnesota Statute 239.791

 

[EXBMWGUY]

Legally, you're not supposed to do that in MN. Are the gas station operators really that clueless that they don't see you putting the no-corn stuff in your newer cars?

Minnesota Statute 239.791

Correct.

 

[scottdk]

Correct.

Weird, I just noticed that almost every station on the MN list for pure gas is premium only. Anyone know the reasoning behind that? I don't run premium in my winter car.....only the Genesis. Below is the closest pure gas station to me with it in 91 Octane.

Andover UNBRANDED 91 Bill's Superette 14041 Round Lake Blvd Nw

 

[radicaltimes]

using premium without corn (still available here if you look) nets about 15% better fuel economy which pays for the price premium..

Gas that doesn't have ethonal in it has more BTU's, that is it produces more energy. But premium doesn't produce more power it has a higher resistance to predetonation. Some cars will have a little more power on premium due to the computer being able to advance the timing.
So any gas that is 100% gas will give you better mpg.

 

[Ernie3647]

http://pure-gas.org/index.jsp

Hope this helps guys.

 

[maxmar04]

Regular. All cars in the US are made to run on 91 octane or lower. any of you putting in higher than mid grade are wasting your money.

 

[Jimmmmbo!]

Weird, I just noticed that almost every station on the MN list for pure gas is premium only. Anyone know the reasoning behind that? I don't run premium in my winter car.....only the Genesis. Below is the closest pure gas station to me with it in 91 Octane.

Andover UNBRANDED 91 Bill's Superette 14041 Round Lake Blvd Nw

People who run "vintage" cars are expected to want the best gasoline octane to prevent pre-detonation and reduce long-term engine damage. So high octane is sensible for "as little" as these cars get driven and are considered "valued". It's not expected (by the govt ) that this fuel is used in MN mainstream cars, which as I mentioned before is illegal in MN.

 

[Jimmmmbo!]

http://pure-gas.org/index.jsp

Hope this helps guys.

Great, as long as it's legal. In MN, it's not worth it for me to take that risk, even if gas station operators are clueless.

 

[Jimmmmbo!]

Regular. All cars in the US are made to run on 91 octane or lower. any of you putting in higher than mid grade are wasting your money.

The OP drives a 3.8. It's not clear if there is a difference (as I mentioned earlier from the owner's manual) if premium makes a difference in "performance" over regular.

Generalizations like this are a bit silly. The vast majority of turbo-charged cars with their higher compression ratios demand premium (as specified by the manufacturer) to prevent pre-detonation that utlimately leads to cylinder piston/head destruction. I've seen it first-hand.

Believe it or not, there are still a lot of cars out there that "require" premium to ensure pre-detonation doesn't happen AND don't program their computers to handle the situation of regular gas because it saves them money. Don't be fooled. Always follow the owner's manual.

It's just not clear in the Genesis case as to what's beneficial versus what "could be" destructive long term for the V8 ...

 

[scottdk]

People who run "vintage" cars are expected to want the best gasoline octane to prevent pre-detonation and reduce long-term engine damage. So high octane is sensible for "as little" as these cars get driven and are considered "valued". It's not expected (by the govt ) that this fuel is used in MN mainstream cars, which as I mentioned before is illegal in MN.

So would a person be wise to run this fuel in the winter months when it's cold etc.? Filled up today and snapped a pic, which is WAY bigger then expected.....

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[mcginnpm]

That means that with a 10 gallon tank, which would have roughly 1,140,000 BTUs available for energy (10 gallons x 114,000 BTUs per gallon of pure gas), you subtract ONE gallon, or 114,000 BTU, which leaves 9 gallons with 1,026,000 BTU. Now replace that gallon with one gallon of ethanol, at 76,000 BTU, and your 10 gallon tank now has less than the original 10 gallons worth of BTUs, but still has 1,102,000 BTU. Calculating the percentage yields 96.7%. So if your engine was giving you, say 50 miles per gallon on 10 gallons of pure gasoline (500 miles), with a 10% blend you'd go a bit less at 48.3 miles per gallon (483 miles). That's not a big DROP in economy and can probably be compensated for by changes in driving habits alone.

There's just one flaw with this analysis. 100% of the BTU's in fuel do not go into moving the car forward. Much of that energy is lost to heat, overcoming friction, etc.

For simplicity let's say that 25% of the energy in the pure gas noted above (i.e., 1,140,000 BTU's x 0.25 = 285,000 BTU's) is converted into velocity while the other 75% (855,000 BTU's) is lost to heat, friction and whatever else.

The level of friction does not change just because you use a different fuel, and the heat produced by the engine and other energy losses are essentially constant relative to the fuel type. So, in your 10% ethanol mix example, where there are now only 1,102,000 BTU's available in the tank, 855,000 BTU's will still be consumed by heat, friction, and whatever else, leaving only 247,000 BTU's of energy to move the car.

That loss of 38,000 BTU's accounts for about 13.3% of the available "car moving" energy (vice the 3.3% loss in total available energy you note above). So a tank of gas that once moved you 500 miles will now only moves you 433 miles. Now that's a bit more significant!

Try that kind of math with E85 instead of E10 and see what the impact is.

http://en.wikipedia.org/wiki/Engine_efficiency

 

[mcginnpm]

Gas that doesn't have ethonal in it has more BTU's, that is, it produces more energy. But premium doesn't produce more power it has a higher resistance to predetonation. Some cars will have a little more power on premium due to the computer being able to advance the timing.

And engines designed to run on premium can have a higher compression ratio which results in higher efficiency which equates to more power available. Have you ever wondered why turbos call for premium fuel?

(read the "Compression Ratio" paragraph at http://en.wikipedia.org/wiki/Engine_efficiency)

 

[Jimmmmbo!]

So would a person be wise to run this fuel in the winter months when it's cold etc.? Filled up today and snapped a pic, which is WAY bigger then expected.....

Not sure what you mean by "wise". As a consumer, there's no doubt this fuel is the best fuel you can buy for your Genesis in MN commercially, no matter what time of year it is because it is 100% gasoline.

MN Politicians and farmers would disagree with this, which is why they passed a law againsting using unblended fuel in the mainstream.

By the way, did you know that current MN law requires a 20% ethanol blend in all mainstream gasoline starting in 2013? Talk about bad news for your engine.

 

[scottdk]

Not sure what you mean by "wise". As a consumer, there's no doubt this fuel is the best fuel you can buy for your Genesis in MN commercially, no matter what time of year it is because it is 100% gasoline.

MN Politicians and farmers would disagree with this, which is why they passed a law againsting using unblended fuel in the mainstream.

By the way, did you know that current MN law requires a 20% ethanol blend in all mainstream gasoline starting in 2013? Talk about bad news for your engine.

My main concern was with water in the fuel system due to the cold in the winter months. I noticed pure gas was about 50 cents more per gallon then the normal garbage, but I'd pay more for no corn anyway. I'll eat the farmers corn, not pollute my car with it

 

[sandy]

Is it true that using premium in an engine that calls for it will produce better mpg than using regular and so may also be more cost efficient? I believe I read that somwhere.

 

[Jimmmmbo!]

Is it true that using premium in an engine that calls for it will produce better mpg than using regular and so may also be more cost efficient? I believe I read that somwhere.

You may not know it but you're asking a loaded question.

A car "designed" to run on premium needs premium to ensure it doesn't incur significant engine damage over the life of the car.

A car "recommended" for premium and uses premium might be cost effective for the price versus gas mileage using regular. But it has never been proven empricially for all cars. It depends on the design of the car (electronics and engine working together among other things).

Bigger problems with contemporary cars that "recommend" premium are likely associated more with the ethanol mix than the octane rating IMO.

 

[EXBMWGUY]

My main concern was with water in the fuel system due to the cold in the winter months. I noticed pure gas was about 50 cents more per gallon then the normal garbage, but I'd pay more for no corn anyway. I'll eat the farmers corn, not pollute my car with it

One of the worst contributors to water in the gas is the condensation from driving around (but mostly the car sitting around) with a 1/2 to 1/4 tank of gas most of the time. I think filling up more often does a lot to mitigate water in the tank.

Also staying completely away from SA and PDQ, whose gas is completely inconsistent in its quality and purity (and I don't mean puregas, as in corn-free). I have learned the hard way spending hundreds on cleaning up contaminated fuel systems. Kwik Trip is a great choice if you want really good, top-tier gas at less cost than the majors. Also, I've used their 89 octane (often priced same as regular) as an alternative to premium. None of this however, is as good for your car, I believe, as BP 93 or any top tier gas without corn.

 

[scottdk]

One of the worst contributors to water in the gas is the condensation from driving around (but mostly the car sitting around) with a 1/2 to 1/4 tank of gas most of the time. I think filling up more often does a lot to mitigate water in the tank.

Also staying completely away from SA and PDQ, whose gas is completely inconsistent in its quality and purity (and I don't mean puregas, as in corn-free). I have learned the hard way spending hundreds on cleaning up contaminated fuel systems. Kwik Trip is a great choice if you want really good, top-tier gas at less cost than the majors. Also, I've used their 89 octane (often priced same as regular) as an alternative to premium. None of this however, is as good for your car, I believe, as BP 93 or any top tier gas without corn.

Thanks for the response. I have a Kwik Trip about 2 minutes from me, which is normally where I fill my my cars, except the Genesis. I would always go to BP for the 93 octane. As of yesterday, I put 7 gallons of the PURE GAS in my car. Also known by some as E0 instead of E10. Went to St. Cloud and back. I plan to use this fuel indefinetly in the spring since I'll be putting my car away for the winter soon. Just a heads up at the station by me with pure gas is 91 Octane and $.60 more per gallon, so I paid $3.79/gallon for the good stuff. On another note, I was reading about cars that are 1998 or older should be running pure gas because they were not built to run on E10 since the law in MN for E10 has only been in effect a little over 10 years. I am actually going to run this in my other car every fill up starting next tank.

 

[EXBMWGUY]

Thanks for the response. I have a Kwik Trip about 2 minutes from me, which is normally where I fill my my cars, except the Genesis. I would always go to BP for the 93 octane. As of yesterday, I put 7 gallons of the PURE GAS in my car. Also known by some as E0 instead of E10. Went to St. Cloud and back. I plan to use this fuel indefinetly in the spring since I'll be putting my car away for the winter soon. Just a heads up at the station by me with pure gas is 91 Octane and $.60 more per gallon, so I paid $3.79/gallon for the good stuff. On another note, I was reading about cars that are 1998 or older should be running pure gas because they were not built to run on E10 since the law in MN for E10 has only been in effect a little over 10 years. I am actually going to run this in my other car every fill up starting next tank.

I've found 92 puregas at fleet farm but have not used it because I don't know enough about Fleet Farm gas. Also, I've found 92 puregas at some Shell stations in WI. Maybe every other fill-up! That's 5% instead of 10% right

 

[Jimmmmbo!]

In general, most cars produced since the 1980s have no problem with E10. I think Minnesota only qualifies cars as "vintage" pre-1975, but I'm not 100% sure on that.

There's a good whitepaper on ethanol if you're interested here: http://www.goldeagle.com/UserFiles/file/STA-BIL%20files/White_Paper_Ethanol_%20Blended_Gasline.pdf