GTI fuel rating (95 RON)

[Hawaii-Five-O]

Can some of our lucky forum members check what fuel rating the new GTI is supposed to use? I think there should be a sticker on the inside of the fuel filler door (it is on my Scirocco which says 95 RON).

In the GTI PDF brochure it says the fuel grade to use is 95 RON (minimum). However, as it says minimum, does this mean the engine is variable and could benefit from using 98 RON?

[GolfTi]

95 on the filler cap.

I will try 97/98 on the next fill up to see if I notice any difference.

[barrym381]

best running them on v-power 

[Hawaii-Five-O]

Watch this and see if you change your mind on your octane rating
Stick with it, it's fascinating

http://www.youtube.com/watch?v=D9nhXNarFdg
(Link courtesy of p3asa)

[p3asa]

And remember there is a part 2 also 

It does make some interesting viewing though.

[Johnc41]

The guy on the video makes total sense and you are wasting your money with anything more than 95. I agree I run 5 gti's on 99 then tried them all on 95. Made no difference whatsoever to driving or mileage, it's a complete waste of money.

[Bill_the_Bear]

The new EA888 has variable cam timing and height.  From other things I've read I was lead to believe the higher octane fuels will have an effect on variable timing engines.  From the video I guess this might be because varying the cam timing will adjust the compression ratio at the point of ignition (and cam height adjusts the mixture?).  Can anyone confirm?

My main confusion is what is the mechanism the ECU uses to determine when to advance the timing?  In other words how does it detect/know that the fuel is different?  Presumably if your going to get better mpg then you need less fuel to be injected so how does the engine determine this?

Way back in my Chemistry A level I had to design a fuel which included maximising the octane while minimising the cost.  From what I recall it was a lot more complex than just adding mtbe or whatever it was he mentioned in the vid.  I'm wondering if in the US the fuel is not as complex.  The UK fuel 95 or 97/99 had maybe 5-10 different components IIRC.

[Bill_the_Bear]

The guy on the video makes total sense and you are wasting your money with anything more than 95. I agree I run 5 gti's on 99 then tried them all on 95. Made no difference whatsoever to driving or mileage, it's a complete waste of money.

Mk5 does not have variable timing.  Apples and oranges.

[Johnc41]

The guy on the video makes total sense and you are wasting your money with anything more than 95. I agree I run 5 gti's on 99 then tried them all on 95. Made no difference whatsoever to driving or mileage, it's a complete waste of money.

Mk5 does not have variable timing.  Apples and oranges.

I Had 4 mark 5 gti's and had them all remapped and the ed30 had over 300bhp and it made no difference whatsoever. It is complete and utter tosh.

[Johnc41]

I also tried the same with my mk6 gti before remap and after remap, I even used asda petrol and it made no difference with fuel consumption or driving.