The Handbook says that you can use Premium 95, so that's what I do. I know that Super is dearer, but does Super give you a better MPG? If it does, then it kind of pays for itself in a roundabout way!

I'm not 100% sure about super (97RON) but most people seem to get better MPG with Optimax (98RON) which seems to cancel out the price difference like you say.

I've been running on Optimax for about 2 months now and the car seems happy enough.

It might be worth resetting your ECU to feel the difference quicker if you change.

Think I read on here that it's usually a good idea to avoid a petrol station if the tanker is there as all the **** will be floating around the tank just after they fill them up and it needs time to settle so you don't go sticking it into your car. Might have made that up though

I always use 98 ron, get better economy and better throttle response (at least it feels more responsive!)

I tried one tank of Optimax once...

Didnt notice any change..

But after reading this, and then the Lexus knowledge section on ECU resets,

I am gonna fill up again with Optimax, and then I am going to pull out the relays as suggested in lexus knowledge for over 30 seconds,

we shall see...

I've used 'regular' Super Unleaded and Optimax before in previous cars and noticed a marginal difference in performance, but I never realised that you got better MPG with it. Once I'm low enough I'll try some Optimax again and pull the EFI fuse, as described in the Knowledge Base, to speed up the ECU learning, then I'll clock my MPGs to compare to Premium Unleaded.

My Dad says he's noticed his 1995 GS300 engine pink on occasions with premium unleaded when driving in warm weather conditions.

if i dont mess about with the ECU, will it take a lot longer to notice a difference? I dont usually go under the bonnet (except to top up the screenwash!!).

Right...

First bout of £30 of Optimax gone in.

Pulled out the ECU fuse, 20amp..

Then went to PULL OUT THE ECTS FUSE!

It wasn't in the correct fuse slot!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1

In fact the ECTS slot was empty.

WHY? ( I do have an auto of course)

So, now I have placed a spare 15amp fuse in the ECTS slot...

I think there is an improvement in acceleration.. I like it.

Dont know now whether this is down to the fuel or the replaced ECTS fuse now?