# 90 Octane no ethanol or 93 Octane 10% ethanol?



## yourdoinitwrong (Aug 7, 2011)

Tallboy said:


> A gas station I frequent gives me a choice...for the same price, I can buy 90 octane pure gas or 93 octane with 10% ethanol. Which would you use and why?


I would go with 93 octane and 10% ethanol. The engines are built to handle up to 15-20% ethanol anyway. Ethanol itself has higher octane than gasoline and has some cleaning properties too. The downside to ethanol is it has less energy per gallon that gasoline (measured in BTUs) but at a concentration of only 10% you really wouldn't notice a difference.


----------



## Crewz (Jul 12, 2011)

You're probably looking at pretty much the same BTUs between the two. One of the reasons they cost the same. I would go with the 93 corn mix for environmental reasons.


----------



## bartonmd (Jun 30, 2011)

The 10% ethanol will typically drop mpg by 5% or so, per my logs book in the Trailblazer and LeSabre... (though that's somewhat offset by the difference between 90 and 93 octane between your 2 choices)

It not only takes more energy to make ethanol than it produces, but using corn for ethanol makes everything else we eat more expensive... 

Mike


----------



## 70AARCUDA (Nov 14, 2010)

...depends upon your driving criteria:

A) want _slightly_ more *milage*, use the 90 octane no ethanol fuel (E0).

B) want _slightly_ more *performance*, use the 93 octane with ethanol (E10) fuel.


----------



## wbwing (Feb 23, 2011)

I would definitely go with the 90 octane most of the time. You're getting more knock resistance and closer to mbt as it is going to a higher octane. And the 100% fuel will give you better fuel economy. I'm big on environment and I'm definitely against ethanol (corn specifically) for the reasons cited above. Also ethanol is not good for engines specifically for the cleaning properties mentioned. Clean injectors are good, but clean piston rings not so much. Ethanol tends to clean of the lubrication on the bore walls, causing premature wear. Even engines "rated for ethanol" have trouble with this fact. 10% isn't terribly bad, but I would use the 100% fuel for these reasons.


----------



## shawn672 (Oct 31, 2010)

@ wbwing
93 octane + 10% eth does not cause knock


----------



## WHITECO (Mar 31, 2011)

I would with 70aar depends on if you want mpg of performance...and both his suggestions are bang on


----------



## wbwing (Feb 23, 2011)

I don't mean you're getting more knock resistance or closer to mbt on the 90 octane or that than the 93 octane. You're getting more knock resistance compared to base 87, plus you get extra benefit of more energy from the extra fuel.


----------



## 72buickgs (Mar 20, 2011)

i would stay with the 90 octane. keep the corn in the field.


----------



## 70AARCUDA (Nov 14, 2010)

72buickgs said:


> i would stay with the 90 octane. *keep the corn in the field*.


...and _in_ the Whiskey Bottles!


----------



## wilsonhines (Jul 12, 2012)

Ya'll take a look at my last 500 mile drive with 93 Non-Ethanol as compared to Ethanol and see how you feel about it at that point.Non-Ethanol versus Ethanol on a 500 mile drive: SurpriseBTW, the environmental reasons for using ethanol are false starts. It takes more fossil fuels to create a gallon of ethanol than the gallon of ethanol you get!


----------



## jsusanka (Jan 31, 2011)

Go with 90 octane. Ethanol sucks IMO wish only I had a choice where I live. Everything has ethanol in it where I live. Closest non ethanol station is like an hour and a half one way away.


----------



## ErikBEggs (Aug 20, 2011)

No ethanol bashing! E10 has 98% the BTUs of E0. Buy whatever is cheaper (most likely the ethanol). Simple question if you ask me...


----------



## hawkeye (Mar 31, 2012)

I've run all the types, and I agree that the non-ethanol gets slightly better mpg--although it's less than 1 mpg any time I have compared. The octane has never made a difference in my mpg. I get just as good with 87 as 93. Ethanol actually produces a lot of jobs around here and has helped us out in the midwest. The plants in this area are reducing the amount of foreign and domestic OIL that is consumed by our country. I still will buy the non ethanol in other states if it's within 2 cents to try to get the better mpg. MN is only ethanol, unless you are buying for a snowmobile or recreation equipment. I'm a little worried about mpg if they do go to E20, but I assume the price would come down.


----------



## 70AARCUDA (Nov 14, 2010)

Here's what GM told EPA about testing of 2013 Cruzes and 91 octane:

"*91 RON FUEL TESTING COMPLIANCE*
 
The knock sensor does not activate in any way during the FTP (or the SFTP as applicable) and the HWFET, and the calibration is designed to operate on 91 RON gasoline without the need for spark adjustment.

The city and highway fuel economy test result differences between comparing 91 RON operation and 96 RON operation is within 3%, and there are no emissions increases (beyond normal test variability) using 91 RON fuel when tested on the FTP (or SFTP, as applicable)."


• Source: page 51 in this GM-to-EPA document: http://iaspub.epa.gov/otaqpub/display_file.jsp?docid=28317&flag=1


----------



## Rednblak (Jan 12, 2013)

So, after checking out the website _ Ethanol-free gas stations in the U.S. and Canada _most of the zero ethanol stations listed in the vicinity I frequent in South Carolina are pure 87 unbranded or BP. I'm thinking I'd likely be better off with 89-91 for an Eco 1.4 turbo. Thoughts?


----------



## spacedout (Dec 7, 2010)

Rednblak said:


> So, after checking out the website _ Ethanol-free gas stations in the U.S. and Canada _most of the zero ethanol stations listed in the vicinity I frequent in South Carolina are pure 87 unbranded or BP. I'm thinking I'd likely be better off with 89-91 for an Eco 1.4 turbo. Thoughts?


Don't go out of the way getting ethanol free gas, at best I have seen 1MPG difference. Most on here do agree though that 89-93 octane fuel the car runs smoother & gets significantly better MPG than 87 octane. For me its a 3-4mpg difference average. 

I realize this is an old topic, but from my unscientific testing my car runs better on 10% ethanol 93 octane than 91 octane pure 100% gas. I have experienced knock on hills with the 91 octane, none with the 10% ethanol 93 octane. This does make sense, one of the benefits of E85 is ethanol's cooling properties, so even 10% would make a difference.


----------



## spaycace (Feb 9, 2012)

bartonmd said:


> It not only takes more energy to make ethanol than it produces, but using corn for ethanol makes everything else we eat more expensive...
> 
> Mike


I'm thinking the ONLY reason this would be true is because of government involvement. I'm not sure the last time you traveled through "corn country" in Iowa, or Nebraska, (Just so you can see thousands and thousands of unfarmed acres) but thanks to good 'ol Uncle Sam's subsidies for corn growers, for quite a long time, there was more money in NOT raising crops than there was in actually farming! There's plenty of corn piled up on the ground all over those areas, so I don't buy the whole "using corn for ethanol makes everything that uses corn more expensive" BS scapegoat. Ethanol has been in production for a LONG time now, but all of a sudden, it's the production of ethanol that's making everything expensive? I don't think so!!


----------



## getincrumpdup (Jan 12, 2015)

this is why i would choose the 90 non ethanol. for one the 90 non is a better fuel base and refined better and that's how it achieves a 90 octane rating. the 93 ethanol version is a low grade fuel refined less with more impurities and a likely less than 87 octane base then ethanol is added to boost its octane ratings so basically the oil companies can call it premium its poor quality gas with ethanol mixed to make it 93 octane which may seem better however its actually a dirtier fuel and pollutes more. oil companies do this to sell sub standard gasoline (dirty gas) by adding ethanol and boosting the octane levels to make an extra buck. all the while you think its less polluting but actually it is worse. i have a local gas station that sells 91 octane non ethanol i been using it for 2 weeks and have seen a 3 mpg increase in short city trips according to the dic. and i started using it on a half tank of 10% ethanol fuel which i have not depleted yet. i guess ill run it dry and then re fuel with the non ethanol to clean it out and see if it gets even better. and the 1.4t seems to like it.


----------



## getincrumpdup (Jan 12, 2015)

this is true if the oil companies could just let go just 10% of their profits them corn fields would be nearly full. and farmers could make a living. but i'm sure its the big plan of big oil to run out all the farmers then that way they can buy the farm land for pennies on the dollar to produce guess what corn or sugar cane based ethanol greedy bastards. then watch how all of a sudden the media says ethanol is good for your cars after all.


----------



## jblackburn (Apr 14, 2012)

Holy thread resurrection


----------

