General / Off-Topic What's the difference between petrol brands?

[Gortron]

In the UK most car users buy their fuel from the big three supermarkets - Asda, Tesco or Sainsbury.

Interesting the comment above re Tesco fuel. I had a couple of exhaust/MAF sensors replaced on my Corsa during its lifespan (luckily not costing £2k) and my petrol was predominatly purchased from Tesco after the main weekly shop. However i'm sure I heard once that Asda petrol contains a higher percentage of water than other formulas so not good for your engine either.

All the supermarkets use http://www.greenergy.com/ Which uses the same refined dinosaurs remains as everyone else; but with a bit of ethanol from renewables to make vegans feel better about themselves.