Wow! what a smoothie! + advice on petrol?

[GaryM]

Optimax is in fact 98 ron and timing can be adjusted by using my Revo SPS3  

[richy]

Yes, Optimax is indeed 98 RON.

Pinking and Knocking are the same thing, and only happen with fuel that is too LOW octane, as golfvr6 rightly pointed out earlier.  

I think your ECU will 'learn' to advance the timing itself after a while.

[golfvr6]

All ECU's on modern cars will be able to deal with 98 RON fuel no problem, infact on most high performance engines the ECU is set to run on 98 RON.
The engine won't pink with 95 RON because the engine will have a couple of knock sensors on it, which automatically retard the timing at the point pinking occurs.
 

[richy]

I agree VR6.  The Mk4 manual says to use 95RON MINIMUM

[golfvr6]

Most high performance golfs usually say 98 ron recommended on the petrol cap  

[Dizzie]

I thought pinking was caused when your fuel has already combusted before the spark  

lower octane fuels will spontanously combused under compression. the higher the octane the longer you can leave the spark.

just what I read somewhere.

[kniterider]

hope you have fun in your new car matey!!!, just one word of advice make sure when your cambelt is changed you have the tensioner changed also, the twots when i bought mine last may only changed the belt, (at 69,500 miles) now on 80,000 and the tensioner has failed, causing total fookin meltdown!! lol,

Gaz

[nrgizerbunny]

I thought pinking was caused by the fuel igniting too early (ie the spark is too late?)

thats what it says in my haynes manual but it also says "refitting is the reverse of removal " which is an understatement most of the time!

have a nice day

sanj

[golfvr6]

The higher the octane of the fuel, the earlier you can ignite it.
Its to do with the higher octane the fuel, the better it burns.
With lower octane fuel a later spark is needed to prevent knocking. If the low octane fuel is ignited too early then it will not burn properly, so it needs to be compressed for a bit longer.

[richy]

sanj - car's looking sweet, mate