Fuel Question

I oOEddOo I

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Hi All,

How often do you use super unleaded fuel on your s5 or a5?

I understand it supposedly is good to clean out your engine now and then, I have been told it's good to do this once a month, currently I am just running normal unleaded as it is recommended in the fuel cap.

Anyone notice it has improved your mpg and any other benefits?

Many thanks.
 
Hi All,

How often do you use super unleaded fuel on your s5 or a5?

I understand it supposedly is good to clean out your engine now and then, I have been told it's good to do this once a month, currently I am just running normal unleaded as it is recommended in the fuel cap.

Anyone notice it has improved your mpg and any other benefits?

Many thanks.

Pandora's box tbh . For my stage 2 S4, it is always Shell VPower. For 1.4tfsi it is usually one tank of VPower after every 2-3 tanks.

On A3, yes I do feel improved economy and it runs better (some might call it a placebo effect )

https://www.audi-sport.net/xf/threads/which-fuel-supermarket-or-not.370722/


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Pandora's box tbh . For my stage 2 S4, it is always Shell VPower. For 1.4tfsi it is usually one tank of VPower after every 2-3 tanks.

On A3, yes I do feel improved economy and it runs better (some might call it a placebo effect )

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Am I silly to think it will mess up the internal system by switching between the two fuel type ?
 
Am I silly to think it will mess up the internal system by switching between the two fuel type ?

No it won't. If anything modern engines have sensors to automatically adjust their timing to suit different grades of fuel, but if they are optimised for the best they will always give inferior performance and poorer economy and emissions on poorer fuel.


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No it won't. If anything modern engines have sensors to automatically adjust their timing to suit different grades of fuel, but if they are optimised for the best they will always give inferior performance and poorer economy and emissions on poorer fuel.


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once this tank finish momentum fuel will be in and hope the sensor can detect the fuel quality and adjust accordingly.
 
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once this tank finish momentum fuel will be in and hope the sensor can detect the fuel quality and adjust accordingly.

Yours is an S5, isn't it? If it isn't tuned then Shell Unleaded is/should be fine and which is what your fuel cap would refer to as well. On my S4 standard fuel required is 95RON, which means that the ECU timing is set for that fuel time. Like I mentioned above, the ECU will act on knock sensors to allow the timing to ****** for lower octane fuel, but not to advance for higher octane.

However, if it is tuned then and depending on which tuner you use and the fuel it gets remapped to you should that fuel.

Personally, I have used Momentum and BP only on my diesel cars in the past and that too was on few occasions. Shell is and has always beeny first choice.





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I use Tesco momentum in mine at all times. Not sure if it's a placebo effect or not but car 'feels better to me when using this and I definitely see an improvement in mpg on the same drives of 1-2mpg (on the screen) i know a lot of people will say that's unlikely by that's what the screen tells me and judging by the mileage difference I get to a tank of 'normal fuel I'd say it sounds about right
 
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On my S4 standard fuel required is 95RON, which means that the ECU timing is set for that fuel time. Like I mentioned above, the ECU will act on knock sensors to allow the timing to ****** for lower octane fuel, but not to advance for higher octane.
This. Read the manual and absorb what it says, because it essentially says this.

I have a tuned S5 that was tuned on Tesco Momentum. That is what I put in it, but putting Momentum in an untuned car is unlikely to make any appreciable difference.
 
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I am fairly sure that the stock S5 ECU does not advance timing to take advantage of a higher octane than what Audi optimised it for (95 RON) and so I would be very surprised if the stock ECUs of any other model do. However there is reason to believe that the batch control of fuel is not perfect and so occasionally you could buy a tank of 95 which is not quite that and so the ECU will ****** timing. If we therefore reason that even a bad batch of 97 RON will still be above 95, then on average over many tankfuls it is possible that an engine optimised on 95 RON will run more efficiently on 97 RON.

As for cleaning that is all down to additives. "Super" will not inherently have more or better additives than "Unleaded", it depends on the brand. I imagine that specialist additives which come in a bottle will do a better job that paying for a certain brand of fuel just for its additives.
 
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