I`m still quite new to scooby`s and have had mine 6 weeks, have just been looking on this site and there are suggestions that you put octane boost in with your optimax. Why is this? And what would happen if you didnt use the octane boost?

 

You really only need to use octane booster if you've got a JDM/imported car.
The imports are set to run on 100 ron fuel and seeing as the best we can get is Optimax/98 ron the booster gets added to up this figure.
If you've got a UK car then its not nescessary as the ecu is mapped to use UK fuel, unless its heavily modded.

There are various posts regarding boosters and thier worth just do a search and put asside an afternoon for reading

Mark.