Unleaded or super unleaded?

Originally Posted by hovis

do you find it sexually arowsing ?

Quite the opposite.

Top tip chaps, things going a little quickly?.....think Hovis.

I use super unleaded (93 octane over here) don't think it makes a huge difference if any. I'll have to check my spread sheet to see if there was a difference in mileage, but probably not.

93???? Thats low. we get 95 as standard, 97 optional at most petrol stations and 99-102 at a selected few.

BTW I use 97.

[Bluepete]

I'm sure I read that the Supers had better cleaning properties than regular, so I run a tank through every now and then. Not sure I can tell any difference in power, although it does accelerate better, but that's 'cos my wallet is much lighter after the fill up!

The higher octane gives a stronger explosion resulting in higher compression and therefore more power. The trick for grey import cars is to buy a Fuelcat (which adds lead to raise the octane) and run on standard fuel with the benefit of added performance. No reason why you can't fit on to a bike. That and super unleaded would result in around 100 octane!

Originally Posted by sideshow46

93???? Thats low.

Heard somewhere that American RONs are bigger than ours and the fuel is the same, not sure if it's true or not though.

Originally Posted by R20MAD

The higher octane gives a stronger explosion resulting in higher compression and therefore more power. The trick for grey import cars is to buy a Fuelcat (which adds lead to raise the octane) and run on standard fuel with the benefit of added performance. No reason why you can't fit on to a bike. That and super unleaded would result in around 100 octane!

The octane rating is measurement of the fuels resistance to knock (the tendancy of the fuel to detonate before the spark due to the compression and retained heat) therefore with a high octane fuel the spark can be nearer in time to the piston reaching the top of it's stroke. More of the energy is used in pushing the piston back down again.

A higher octane rating is therefore only useful in an engine that has a knock sensor that the ECU can use to help adjust the ignition timing. Traditionally the Japanese have lead the way in technology which I guess is where your referance the grey imports comes from.

This is only as I understand it and there is always the possibility I'm talking out of my ****.

Edit: I'm not sure how this applies to the SV engine.

http://www.torquecars.com/articles/f...ne-ratings.php
Anyone really bored should read this article all about RON and it's meaning.

Right then as Im too lazy to go and dig mine out what do the manuals say about RON ratings for curvys and for pointys?

[glade]

AS PP said, higher octane fuel is more resistant to detonation (knocking). Some high octane fuels e.g. v-power also have cleaning additives which reduce the buildup of carbon on the back of the valves etc.

The SV doesn't have a knock sensor, (so cannot adjust the timing to get a benefit of a higher octane fuel) and is probably not mapped for high octane fuel.

I don't see the point in filling with anying other than 95 octane fuel unless you want the cleaning benefits.

(I think that the grey import bit is a red herring: Its because the jap imports are highly tuned NA or turbo motors that have knock sensors so can adjust the timing to make the most of high octane fuel.)