When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It's a very good idea if you own an import, with an ECU mapped for 100 RON fuel. It's also a very good idea if you own a modified UK, with a Knocklink showing that you're detting. And it's a good idea if you can't get hold of Super Unleaded or Optimax.
The best one is NF, I believe. Click here for the website.