I'm sure I saw a web-site recently that said to use premium unleaded in an Octavia but I can't find it now. I've always used 95 octane in my 1.6 FSI petrol engine. Has anyone done any tests to find out whether it's actually worth the extra cash in terms of performance to go for premium?

Not sure about the 1.6 but it's worth it in my VRS.

I get about 3mpg more and the car runs nicer and has more pick up.

Try it for a couple of tanks. I think all the recent Octy engines are made to run on 98RON even the 1.4

Ordinary will be fine then.

I did read reports of the FSI engine in the Golf pinking if using anything less than super unleaded.

Althought that might have been on supermarket unleaded.

I've used super unleaded in my Felicia but as it's an older engine it doesnt seem to have had any impact but the engine did rev that little cleaner and smoother.

So my opinion is try it on super unleaded to see if it makes a difference.

Otherwise if the differences are minor with no problems you'll prob be better off using normal unleaded as it's cheaper.

i personally use shell vpower, but the engine is a 2.0. it didnt like tescos super unleaded when i tried it and produced poor mpg. thinking back to when i had a 1.6 i used to do 3-4 fill ups on 95 ron and one on 97 (or higher). seemed to like that.

Given the (ridiculous) cost of petrol now, regular or super I find the improved economy of super (upto extra 3mpg) is actually worth the additional cost per litre.

Eg:

reg £/litre 1.20

super £/litre 1.25

@ 4.5 litres/gallon £/gallon (reg) = £5.40; (super) = £5.625

if reg economy = 35mpg then pence/mile = 15.42

if super economy = 38mpg then pence/mile = 14.8

So its actually 'cheaper' to go for super - plus you're getting the full 'enjoyment' out of the engines tuning due to improved throttle response etc.

Hope my maths makes sense and thats of some use to you.

JD