I have been told by two places not to use Tesco fuel. First was Revo and second was my mate who melted his head on an EVO 400 because the fuel was so bad. I've justed Revo my Cupra R with a stage 1 and the boost was intermitant. Just fitted a Bailey DV30 and Green cotton filter and it feels like a different car. Smoother, faster and more throttle response.