Fuel Octane and fuel additives

[BigCatXJS]

So recently I had no choice but to fill-up with regular Esso 95 octane unleaded. 50 or so miles later and I'm noticing that the cat is somewhat lethargic and certainly not as sprightly as normal.

A couple of fills later with Shell 98 octane nitro unleaded and some shots of Millers Petrol Power Ecomax and I'm back scaring OAP's with fast passenger rides (it's a charity thing: http://sportingbears.co.uk/index.php/vi ... rides-info) .

So a couple of questions to chew the cud on;
- Was I unlucky and just got a poor batch of fuel from the Esso garage?
- Should 98 octane fuel really make such a difference?
- How much difference does Millers Petrol Power Ecomax make?

I should add that my ECU was modified some time ago as part of a series of AJ6 Engineering performance upgrades and that I usually run the cat on Shell 98 octane nitro unleaded. The last two fills I have started adding Millers Petrol Power Ecomax and it *seems* to have made a difference... I have no scientific proof or real evidence to prove anything, just my perception.

Thoughts?

[ukjag]

95 octane should only have 5% ethanol, but some has more, which being corrosive and hygroscopic, will help to reduce the life of your fuel filter. Clean out the swirl pot, and clean the filter in the swirl pot, if very dirty it can be pulled close to the end of the pick up pipe and reduce flow.Then if you fit a new filter behind the spare wheel, all should be good!
There are rumours in the trade that certain supermarket petrol is very bad at the moment, with added water!
I do believe in Millers!

Ken, ukjag