My first Golf: Mk2 Gti 16v - What petrol do I use 95 or 98?

[ScottMk2Gti16v]

Hi, I've just bought my first Golf after some years wanting one!

It's a 1991 J-reg Gti 16v in near mint condition - nice old couple have run it for the last 7 years only doing 4000 miles a year and having it serviced/fixed with no cost spared.

However, the back box on the exhaust is slightly blown and needs replaced: Questions-
At low speeds at low revs it's being spluttery and losing power, you know the kind of judering it give. At High speeds it's no probs.  Starting from cold is worst, at the first junction it almost stalls then pulls away like a kangaroo.   Would this be a direct result of the exhaust being blown?

Also what petrol do I use in it? I've read a number of threads here all going on about 95, 98, 98 RON (whatever that is?) but am not sure about it. I note inside the petrol flap it's got a sticker in German that states 98 oktane min. or something like that.   I put in some 98 octane and not long after it started this spluttering, I've since put in some 95 and it seems a little better but not gone.

Questions is:
Is the problem mainly:
a) the exhaust
b) the fuel
c) combination of both
or
d) something more major?

Thanks for any help.

[rowlers]

they are meant to run on 98 (super unleaded) but apparently the timing can be retarded to run on 95.
I personally use 95, cos 98 makes no difference to mine at all. I've also read somewhere thought running on 95 continuously can blow the head gasket!!

but its up to you!

[ScottMk2Gti16v]

Does the timing retard (what does that mean?) automatically?

[knobby]

Surely when these cars were made 98 super Unleaded wasnt available so how was it surppose to run on this type of fuel.

??

Knobby.

[gti jim]

98 ron and blown cylinder heads must be a kentucky fried mouse 

[rubjonny]

You should run it on at least 97 ron petrol, as it says in the manual
It can be run on lower ron petrol in an emergency, but you are supposed to take it easy and top up with 97 ASAP.
Of course the timing can be adjusted to make it run fine on 95ron, but you loose performance.

The 16v does not automatically retard the ignition timing for 95 ron petrol, which is why you can't use it.  However the MK2 8v digifant can so 95ron petrol is not a problem. Not that this helps you in any way though 

[ScottMk2Gti16v]

Ok, so lets say my mk2 gti 16v has been run on 95 RON for the last 5 years and now I start filling it up with 98, how would the car react to that?   It does say to use 98 on the petrol cap.

[Gambit]

if your gonna start running 98 then just have the timing re-checked

also get the CO% set.

infact just read the 16v setup in the maintenance section

everything your describing is just a badly setup 16v!

[ScottMk2Gti16v]

The page you mention isn't working?   Just diverts to BT's homepage.  Any chance you can fix it or post the info here?

Cheers

[ScottMk2Gti16v]

PS - What is the CO% ?