95 RON in a MkII DX

[mmacneill123]

Folks, does anyone know the details of the ignition timing retardation required for making it absolutely safe to put 95 RON in a G-reg DX? Know i can use 98 RON without modification which is what i have been doing but getting a bit irritated at paying a 20p premium on the motorway (compared to being at home) at times for using it!

Cheers!

[Nate]

you may need to retard the timing slightly if it pinks

[mmacneill123]

Thanks Nate, it is just i used to have an official VW list of all the engines and all the adjustments when there was the big changeover of fuel. I can remember there was a significant difference in the timing even for the later DXs.

From the Golf GTi site i got this:

If your Mk1 Golf is a GTi, then using 95 RON unleaded will require the ignition timing to be adjusted as follows:

1.6 (EG) engine 6 deg +/- 1 deg ATDC
1.8 (DX) engine 0 deg +/- 1 deg BTDC

but i am not sure this applies to the later 1.8 Dx's ?

Mike

[bmseven]

VOLKSWAGEN index

Air-cooled: Fit hardened seats, higher spec (stainless) valves and new guides.

Golf GTI / Scirocco GTI 8-valve models: OK on unleaded; retard ignition timing on cars with engine codes EG (1.6,1976-82), EV (1.8,1984-87), DX (1982-89).

Golf GTI / Scirocco GTI 16-valve models: Use high-octane unleaded.

Taken from The Truth About Unleaded http://www.vea.qc.ca/vea/articles/unleaded.htm

More info here
http://www.honestjohn.co.uk/forum/post/ ... tm?t=11110

[mmacneill123]

That is interesting too but i do know there is a specific recommendation for just how much to retard out there somewhere!!!

[MikeH]

Every car is different, but back it off to about 1 or 2 degrees BTDC. I'd do it by trial and error... Actually no I wouldn't. I'd put 97 RON in it as a minimum, because there's no point buying a performance car, and then killing the performance with crap fuel, and retarded timing.

[mmacneill123]

Hi mate, thanks that is what i was looking for....did have a Scala that was adjusted for 95 and it was fine, never really noticed too much of a performance drop as i am actually quite a careful driver and would put better fuel in when at home, just motorway rip-offs at the minute, almost 20p difference for the Shell V-power compared to local prices.

Could have missed the boat anyway because i forgot to tell the mechanic to set the timing for unleaded but he might not have done the job yet!!!

[Nate]

i used to have an official VW list of all the engines and all the adjustments when there was the big changeover of fuel. I can remember there was a significant difference in the timing even for the later DXs.

you are possibly thinking of when 2* and 4* petrol was phased out in favour of unleaded. a rocco running normal unleaded that has had the timing advanced to just before it starts to pink will whoop one that is running on super expensive and set up by the book

[fonzooorooo]

My experiences: With my timing set up a-la Nate, (on an EX) I'm getting the same miles to the pound with super (at 130.9/l) that I used to get with regular unleaded. Just seems a bit smoother on the super.

[MikeH]

Hi mate, thanks that is what i was looking for....did have a Scala that was adjusted for 95 and it was fine, never really noticed too much of a performance drop as i am actually quite a careful driver and would put better fuel in when at home, just motorway rip-offs at the minute, almost 20p difference for the Shell V-power compared to local prices.

Could have missed the boat anyway because i forgot to tell the mechanic to set the timing for unleaded but he might not have done the job yet!!!

It does depend how you drive. If you're a 'spirited' driver you'll notice a big difference. Fuelling keeps the engine happy and running smoothly, but it's ignition advance that makes the big difference to power, once the engine has got enough fuel.

[mmacneill123]

Thanks MikeH, nice portfolio of vehicles there!