91 octane?

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Bonedrivin

Member

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'14 Mazda 6 Touring w/ Tech - '05 Nissan Frontier LE v6

• Feb 17, 2016

• #1

2014 Mazda 6 - 58k miles

Been using regular 87 octane since I got the car. Yesterday I was distracted when pumping gas and filled with 91. Seems peppier.

Is it just in my head??

Anyone notice a difference in performance when using a higher octane gas? Any downside if I continue using 91?

 

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GerryB

Member

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2005 Mazda 6S Hatch Lapis Blue MTX

• Feb 17, 2016

• #2

Go back to 87. This subject has been beaten into a bloody pulp almost everywhere. No harm, no foul. The only advantage I saw over time was through using alcohol free gad, which just helped my fuel mileage and not really the performance.

Sent from my HTC One using Tapatalk

 

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torquelover

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2015 Soul Red 6 Sport Auto 2016 Accord EX Auto

• Feb 22, 2016

• #3

We run it in the MZ6. Gets better gas mileage, and part throttle response is actually better. I dunno if it's due to it not having any ethanol or being higher octane. The MZ6 sits in the garage a lot undriven, so with premium fuel lasting longer it's a no brainer.

 

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thzpcs

Member

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Speed3

• Feb 23, 2016

• #4

Premium fuel is no different than regular, other than the octane rating. If your car isn't designed for it, you're wasting money. If you can get ethanol free gas, it's better because while the octane of ethanol is quite high, its overall energy content is quite low. Ethanol is also hygroscopic, so it can absorb water.

 

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EvansMazda

Member

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2016 Mazda6 GT

• Feb 27, 2016

• #5

I agree with OP I filled my car with super premium to the brim and it definitely was much more peppy, like regular gas is decaf, premium gas is expresso

 

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sbronemann

Member

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2014 Meteor Grey Mazda 6 Touring

• Feb 28, 2016

• #6

I have tried 91 and 93 octane numerous times over my 76k on my 14 Mazda 6. I have never noticed a difference. Gas mileage is no better from my personal experience. If it was only 10-30 cents difference, wouldn't be that big of a deal. But around here, 91 is 40ish cents difference, and 93 is usually 80ish cents difference. Definitely doesn't make any sense to run it unless the vehicle requires it. Since we have ethanol in our gas, I put in a container of Amsoil PI every 5k or so just for good measure to clean all the garbage out of the motor.

 

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50Joe

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Mazda6 GT, MX5 PRHT

• Feb 28, 2016

• #7

EvansMazda said:

I agree with OP I filled my car with super premium to the brim and it definitely was much more peppy, like regular gas is decaf, premium gas is expresso

Click to expand...

Psychological effect. Octane does not provide horsepower. In fact, 87 octane has more burning "energy" than 93. The only reason to use a higher octane is to prevent detonation in engines that require it. In the past, high compression engines needed the octane to prevent detonation and therefore produce more power because of the compression ratio, cam timing, ignition, etc. Modern engine building and tuning can now have high compression and not require high octane to combat detonation. So, an engine designed to run on 87 like our new Mazda6's will NOT run better on 91 or 93 octane. Yes, I am an engineer.

 

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GerryB

Member

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2005 Mazda 6S Hatch Lapis Blue MTX

• Feb 28, 2016

• #8

That should do it.

Sent from the wrong side of the tracks.

 

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Drogos

Member

• Feb 29, 2016

• #9

it's in your head ....the only time I would consider 93 (91 is not enough of a difference to even give a s*** ) is if I drive loaded, through a death valley ....in the middle of the summer ....on a particularly hot day.....like 120F hot. In that situation extra knock protection can help ....a little. THese ECUs are dumb, they wouldn't know if you put water in the tank. O2 sensors only reports what kind of O2 content comes out of the exhaust and and guesstimates timing based on that ....and knock itself of course. As far as I know only VW and Audi has sensors to on the fueling end of things to adjust timing on the fly....might be wrong on that though .