1.6 FSI - Various fuels and RONs make no difference.

Goochie

Member
Over the last half a dozen tanks of fuel, with the same driving style and the same basic journeys I've been trying various fuels;

Tesco 99 RON
BP Ultimate
Shell Optimax
Shell fuelsave
Sainsburys "normal"
Asda "normal"

The conclusion of this, having manually calculated the MPG over a full tank each time is that it makes no real difference what so ever to the MPG of the car. There was also no difference in performance.

This may be because my car as the notorious 17" wheels, or maybe because I only drive around town, but all the same, the difference was only in my wallet after each fill up.

My conclusion? I'll be sticking with the cheapest option.
 
Your car was designed to run on higher octane,its probably just to shift the carbon in the throttle body etc.
Lots of Modern fsis need decokes or decarboning from using non detergent fuels
 
The A2 1.6FSI runs much better on 97-99RON fuel.
Not sure of effect on MPG, but I have only filled with 95 RON on 2 or 3 occaisions and each time the drop in power from the engine was dreadful.
If your ECU has given up hope of seeing good fuel then it may not be altering the timing much when you try a dollop of premium unleaded.
 
I have to say, the A2 1.6 fsi is rubbish under 2,000 rpm, once you get it above the 2,000 rpm it's off and reminds me of my old R5 Turbo slightly... (It's got that power delivery that the turbo lag was so good at launching you off at speed 2 days after pressing the accelerator, just the A2 is not as mad!) If I use cheap fuel, it runs like a bag of hammers all the way around the Rev counter, if I use V-power or RON 99 its much smoother and quieter. Not only that, I have a fireblade and ONLY put V-power in that. It's not to be under estimated the power of a fuel that enables the engine to get a clean combustion and thus, be more controllable. The Fuels discussion will always be a long one, but its expensive fuels which where designed to be used for the vehicles that I will be using.
 
i agree to most of the replys myself use only high octane,ran a few times recently on normal just out of interest and im only just getting my fsi back to running normal/responsive,it was running fine till i changed just felt like it was being held back....another few tanks full of high octane and she will be fine..you live and learn.
 
I'm still not convinced and think most of the effects people have with the FSI are purely placebo. For instance, how would a change of RON make the engine run quieter??
 
I'm still not convinced and think most of the effects people have with the FSI are purely placebo. For instance, how would a change of RON make the engine run quieter??

Audi stated in their sales literature that the FSi engine gives optimum performance on 99 octane fuel.
While running on low octane fuel and under certain load conditions, knock sensors detect the vibrations caused by pre-ignition and retard the timing to compensate. When this happens the engine runs less efficiently so performance and fuel consumption are worse. Its quite possible the engine note also changes due to the retarded timing which is why the engine may sound noisier

Cheers Spike
 
I'm still not convinced and think most of the effects people have with the FSI are purely placebo. For instance, how would a change of RON make the engine run quieter??
Because it runs under circumstances in lean burn mode (with a statified gas "cloud"), hence the precise control of ignition/detonation (related to RON) is more complicated than in stoechiometric ratio mode.
 
I remember when I got my A4 3.0 V6 remapped a few years ago by MRC Tuning, the map was optimised for Tesco99 and itgave a maximium additional 6degree advance over the standard adaptive map. One immediate noticeable effect was a quite significant change in the sound of the engine at higher RPMs - where in the standard map it would have a sort of restrained buzzing tone to the engine. But on the remap, over 4000RPM to the redline (raised to 7200RPM as well, heh), the engine made much more of a rasping snarl noise - it really sounded much more aggressive and it really did open up the performance at the top end. Changes in engine timing can have a big impact on the sound and smoothness of the motor.
After the remap, the anti-knock was still able to adapt down to running on "standard" superunleaded, but I have to say it did pink a bit on 95RON after that on full chat...
 
On Buying my A2 1.6 FSI SE, it never seemed to really accelerate properly through the gears and there was a definite flat spot at 6000 rpm, just when you need it to overtake on the motorway.
It ran badly on 95 Octane , ran better but not perfect on 98 Octane,The car was fully serviced and checked out, I fitted new Mini Coil packs myself as the car was quite old and at less than £100 seemed a good ongoing upgrade.
Better but not as it should be.
I then visited friends and relatives in Germany, driving all the way by car, roughly 900 miles each way,
On refuelling in Germany at an ARAL garage, I found they have 101 octane SUPER UNLEADED,
The car drove BETTER IMMEDIATELY, on returning to England, I found by chance that TESCO do a 99 OCTANE (MOMENTUM) .
I did a test first putting in just 99 OCTANE, worked just perfect.
then 98 OCTANE , there was a sharp negative difference of performance through the power band.
SO MY ADVICE IS THAT 99 OCTANE IS THE BEST FUEL FOR YOUR A2 FSI & you get TESCO POINTS AS A BONUS!!!!
 
I too have noticed a difference in performance with higher octane fuel. I stopped off at a petrol station on the way back from collecting the car, and filled it to the brim with the normal lower priced unleaded, and did think at the time that the car didn't feel as punchy as it ought to.

So I ran the car to almost empty and filled it with Tesco 99 Octane. I completely agree with the last post that it's made a marked difference in response, and overall the engine feels a lot more refined.
 
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