The Mk. 2 Fabia VRS is supposed to be able to work on 95 RON petrol but is best run on 98 RON (see inside the filler flap).

 

I have never seen 98 RON in any gas station I have ever visited.  97 RON appears to be available at almost all gas stations that sell 95 RON fuel.  99 RON appears to be available at (some) Shell gas stations and Tesco Superstores.

 

The engine management system is designed to detect knocking or pinking due to the use of 95 RON fuel and to adjust the timing or boost pressure to compensate.  I presume it will do the same with other grades of fuel.

 

For the most part I fill up with 97 RON at whatever gas station is most convenient, if I am desperate I will put some 95 RON in the tank.

 

Can anyone point me in the direction of any credible independent scientific evaluation of the impact of using 95, 97 or 98 RON in a standard Fabia VRS used for day-to-day driving?

I doubt there will be any scientific evaluation.

The car will run fine on any grade, 95, 97, 99 although there is a noticeable (IMO) difference in pickup, smoothness and responsiveness depending on which you use.

I can't comment on what the difference would be in terms of engine life/wear depending on which you use.

I always run mine on 99 from Tesco after taking good advice on this forum.

I recently drove a dealer demo which is obviously run on 95. The difference was huge. The fuel in the tank didn't even cross my mind until I thought - hang on a minute this is less responsive, slower and not as smooth. You should notice slightly improved fuel consumption as well with a higher octane number.

You may put a tank in after using 95 and not notice much. But when you use 99 all the time and then revert to 95, the difference is right there for you to see.

Edited 2 June, 201412 yr by austenw90