Switching from 94 to 91 Octane?

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RobRS3
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Switching from 94 to 91 Octane?

Post by RobRS3 » Thu Mar 10, 2022 1:33 am

With the horrible gasoline prices getting higher every day, I'm trying to find ways to reduce the pain, and by switching from 94 octane to 91 octane for my 2018 RS3. Would be great to know if can expect a noticeable reduction in power or any other side effects? And can the car still be pushed as hard as when tanked on 94 octane?

Thanks,
Rob
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Nige_RS4
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Re: Switching from 94 to 91 Octane?

Post by Nige_RS4 » Sat Mar 12, 2022 12:50 pm

If your car isn't mapped then you shouldn't see any long term issues, but if it's been mapped for higher quality fuel then you need to speak to your tuner as the knock sensors (or whatever the call them these days) may not be able to <beep> the ignition enough to protect the engine. Don't just take their word for it either as the factory sensors can only adjust by a set amount and a decent tuner will change these values as part of their map.

I personally won't be switching to a lower fuel quality - just reduce any unnecessary trips and drive more economically when possible. It's possible to get around 20% more MPG without trying too hard.
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RobRS3
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Re: Switching from 94 to 91 Octane?

Post by RobRS3 » Sun Mar 13, 2022 12:03 am

Thanks, will consider your advice. It is only 7cents a litre cheaper here in my area between 91 and 94. Have been driving much more civilized - slow accelerations and well taking it out only once a week. The other car is a Corolla so been taking this one more often. But really miss my Audi ride so might give in and drive it more than this never the less. It is not tuned yet so glad to hear stock is not a problem on 91 and can always have it adjusted once tuned to match my choice of fuel between 91 and 94. On an unrelated topic, it is such a disappointment that Canada dropped the new RS3 for 2022 models and beyond. While in Europe, and in the U.S. you can still buy the 2022.
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VladT
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Re: Switching from 94 to 91 Octane?

Post by VladT » Tue Oct 25, 2022 11:27 am

RobRS3 wrote:
Sun Mar 13, 2022 12:03 am
Have been driving much more civilized - slow accelerations and well taking it out only once a week.
Did it save fuel?

RobRS3
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Re: Switching from 94 to 91 Octane?

Post by RobRS3 » Tue Oct 25, 2022 12:35 pm

Did not notice much of a difference. Kept using 94.
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