I went this morning to the only place in Belfast listed in millers website looking for their octane boost. No joy there is apparently a problem with the NI distributers. The guy sold me wynns 4 star plus. Bottle says:
harmless to catalyst
increases octane no of unleaded fuel
can be safely used in vehicles normally requiring unleade fuel
Should I use it?
Is it safe to use in my my99 uk scoob?
Help appreciated guys
Andy

 

I would be extremely wary of this, as it appears to be marketed as a lead replacement rather than simply an octane booster. If you check

 

Cheers simon
It certainly has the same name but a different bottle, and bottle clearly states suitable for cars with cats, but I was worried that is why I bought one bottle and not a case!!
I want it for that little extra ummpphh and safety for my first trackday in march. Any futher advice folks
Andy

 

Don't use it Andy - despite what it says on the bottle!

 

Anyone know if Wynns has a website?

 

I wouldn't use 4 star plus.
I've used Wynn's Octan 10+, which I believe is ok for your cat.

Or order some millers from Britain (assuming postage isn't too much).