ive been using normal unleaded for the last well year i spose. probally about 2.5k miles. just read through some old posts explaining dont ever do it its bad for your engine due to pinking! ooops! it drove so much better when i threw some superunleaded in today. i wonder hopw many others have been doing this not knowing

increased boost and thus higher compression would take advantage of a higher RON but 95 should be fine for standard engines.

Ive got the n/a and if i use standard petrol then use the higher 99 it is a huge difference and imports are meant to use the higher grade any how

A higher octane fuel will (all other things being equal) give a more energetic burn in the cylinder for the same amount of fuel.

 

AFAIK the octain rating of fuel has nothing to do with the energy of the fuel its purely the resistance to detonation. The higher the RON the less likely you are to get detonation - often incresed RON fuels actually have less energy content per volume :)

 

You're right, vern936, my bad. I was sort of right in that higher RON allows higher compression and therefore a more energetic burn in the cylinder etc etc. But you're right, it is the resistance to det that allows it, not the energy in the fuel.

http://en.wikipedia.org/wiki/Octane_rating

engines that require higher octane usually deliver more motive power and do more work for a given BTU or calorie of fuel

I'll go and write this out 100 times. :smartass:

from what i understand from reading into it.... jspec cars should be run on higher octane as their feul is a higher rating as standard. ukspec cars are ok to run on normal unleaded if un modified as they were designed to be run on it. something to do with spark plugs i think. que an expert

Ive got the n/a and if i use standard petrol then use the higher 99 it is a huge difference and imports are meant to use the higher grade any how

 

Exactly what I found.

Ive read some where that the valves are harder on the uk models on some Nissan cars , but not read any thing regards the zed

Whatever the reasoning, yes - a stock(ish) UK car is fine on normal unleaded. It's what the handbook says; along with that little sticker saying "95 ron" inside the petrol cap!

 

In Japan a higher octane fuel is available and whilst over there the car may have gotten used to running on it, a stock(ish) TT should by the same rationale get used to running on 95 ron here as well.

 

However in very hot weather, especially as there is a lot of heat under the bonnet of a TT Z32, most of our cars will run better on super u/l during the summer months. I know my UK spec does - it seems to maintain peak performance at the height of the day compared to when filled with regular u/l (and I only ever use Shell or BP; both normal or super).

 

Also when running on V-power, whilst I may not notice much more in the way of performance (outside of very hot summer days), I have noticed that I get a few more miles from a tank full. Not necessarily the same story with BP Ultimate though - that is no different from regular u/l.

 

That's just my experience and it may be different from the rest of you......:innocent:

 

Richard:biggrin: