IF YOUR CAR IS TURBO!!! ONLY RUN 98 RON which one you choose is up to you
as for shell v power... it has been craped, it was a point that our goverment was trying to make, by showing the public that you could use ethanol in petrol
shell was making a massive loss when it came to 100 ron, in transport an refining it... but since the goverment FUNDED the project they made money out of it