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Discussion Starter #1
There are two gas stations here that have non-ethanol fuel. One has 87 octane, but charges 20% more. The other, has 92 octane and is only $0.03 more than most 91-93 octanes stations around here. the 92 octane non-ethanol station has only 2 tanks, so it would mean the mid grade gas should be 5% ethanol.

Would it be 'OK' to run 92 in a Skyactiv? I know, on my previous vehicles, using non-ethanol fuel increased mileage and performance, but I don't want to do anything that would cause problems with the car - it's new!

The compression ratios makes me think that higher octane fuels would be required, but they're not. I don't want to put something in that's going to cause problems.
 

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You can use 87 octane gasoline with ethanol. Using premium is a waste of money. Yes, skyactive engines have higher compression but not enough to cause pre-ignition.
 

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Discussion Starter #5
I filled up with the 87o non-ethanol today. When I refuel, I will post the results. In the manual, it says 87 with up to 10% ethanol, but if there are issues, to use non-ethanol. We'll see what happens.
 

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Dont drive fast! Fly Low!
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I have a 2.5 5 door and I use 89 instead of 87 when prices are better. lol
I wish Mazda had a flex engine. Ethanol gives you more power. But you get more gas often.
Sometimes it's worth, sometimes not.

Get better oil next time, that's where you gotta put some money into.
 

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I have a 2.5 5 door and I use 89 instead of 87 when prices are better. lol
I wish Mazda had a flex engine. Ethanol gives you more power. But you get more gas often.
Sometimes it's worth, sometimes not.

Get better oil next time, that's where you gotta put some money into.
You may as well flush dollar bills down the toilet, because that'll give you about as much gain as 89 octane on a 2.5 with the factory tune.
 

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Dont drive fast! Fly Low!
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You may as well flush dollar bills down the toilet, because that'll give you about as much gain as 89 octane on a 2.5 with the factory tune.
You mean 87 right?
Well, I compared both and I get more miles with 89 than 87. Not a lot, but when difference is about 5 cents, I use 89. More than that will be "cheap" as I can get. lol
Its $4 a gallon for gas. I will start walking only, lol
 

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What I mean is that running 89 octane on your motor is flushing money down the toilet because the stock ECU programming does nothing to take advantage of it.
 

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Dont drive fast! Fly Low!
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What I mean is that running 89 octane on your motor is flushing money down the toilet because the stock ECU programming does nothing to take advantage of it.
Like I said, I get a few more miles when using 89. But when prices are close, like 5 cents.
Over that doesnt have any difference.
 

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I would challenge that you are spending more money than the mileage increase benefit you see. Add up the numbers and check it out.
That's what I have been saying for the lasts posts.
I did and yes, I get more mileage with the 89. Not much, so when the 89 is only up to 5 cents more expensive than 87, I do it.
If it's more expensive than that, go back to 87.
 

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That's what I have been saying for the lasts posts.
I did and yes, I get more mileage with the 89. Not much, so when the 89 is only up to 5 cents more expensive than 87, I do it.
If it's more expensive than that, go back to 87.
What i am saying is add up the mileage increase you get for the dollars, and see if there is any point at all to do what you are doing. Do you get more than 25miles per tank extra with 89 over 87? If not, you are wasting time, effort and money.
 

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mmm, that's not really wasting money...

its modding the car to the point that it knocks unless taken 91, retard the timing...still knocks... and then talk about power gain..what power gain... but dont have the funds to restore to stock airbox form(yet), that's wasting money.

91 you never need on stock mz3's skyactiv or not, 89 may make a tiny difference(feel good factor), but to each his/her own.
 

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Dont drive fast! Fly Low!
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What i am saying is add up the mileage increase you get for the dollars, and see if there is any point at all to do what you are doing. Do you get more than 25miles per tank extra with 89 over 87? If not, you are wasting time, effort and money.
Ok.
I normally do 21mpg, I drive a lot in city, and hwy I always speed up. lol
But normally 21mpg right?
With 15 gallons of tank, I would do 315 miles.
Price of gas is around 3.83. That costs me $57.45...

With the 89, I was doing 21.5mpg. That's 322.5 miles.
And when it was 5 cents more expensive, 3.88, I had to pay 58.20. Less than a dollar.

322.5-315 = 7.5
7.5 / 21 = 0.36
0.36 * 3.83 = 1.38...
If I used 87, I would pay $1.38 more.

But now 89 is 3.97! That's 59.55...
57.45 + 1.38 = 58.83. So now it's not worth.

I know I am talking few dollars, but I am not a rich bastard. If I were, I would be spending all my money on race rated gas for my cars. LOL
 

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Necro post revival.. without a tune, premium gas does nothing for a direct injection engine. Even if it did, the gains would be so minimal, that it wouldn't warrant the added cost of the premium gas.

I'm now tuned for 91 octane and am able to take full advantage of the higher octane level. If you are already paying for the premium gas, you might as well get an Orange Virus Tune and make the most out of that premium gas.
CK
 

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Necro post revival.. without a tune, premium gas does nothing for a direct injection engine. Even if it did, the gains would be so minimal, that it wouldn't warrant the added cost of the premium gas.

I'm now tuned for 91 octane and am able to take full advantage of the higher octane level. If you are already paying for the premium gas, you might as well get an Orange Virus Tune and make the most out of that premium gas.
CK
That is what I am doing, an OVtune for 92 octane, among other tweaks(low end torque and throttle response). Mazda tuned US skyactivs for 87 octane. I will have OVtune to tune it for 92 octane. Additionally, i installed a MSDS header, which deletes CAT1 and pops off the CEL(P0420 or a P2097 if you have a leak on the MSDS header slip fit). The tune can account for a deleted CAT1 so I dont get the P0420 CEL. Or so, I think, Im not an expert on ecu tunes. But i do know if you change your hardware(i.e. upgrades, fuel type) you should probably tweak the software(ecu) too.
 
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