205 GTI 1.9 fuel

[mikey_p]

In the manual it says do not use 95 ron fuel, and to use 97 or higher ron. However I can pretty much gauruntee (I can never spell that word) that mine hasn't been run on high octane fuel all it's life.
How would this affect the engine?

I have already used a tank of Tesco 95, and the car felt responsive and fast enough, then I ran it empty and used a tank of Tesco 99, and I couldn't notice any difference, and if anything it felt slightly less torquey. What do you lot think on this matter?

Thanks

[Mikey G]

It will be ok, would only require a little ignition timing adjustment to ensure that you dont get pinking problems

[sleep envy]

mine runs really rough on 95 - it idles all over the place and has a massive flat spot at 3k rpm

on 97 and above it revs cleanly to the redline

[simes205]

If the timing is set up to run on 97 and you feed it 95 it will pink.
Tuning it to 95 will lose you some power but it won't pink.

[mikey_p]

simes205 said:

If the timing is set up to run on 97 and you feed it 95 it will pink.
Tuning it to 95 will lose you some power but it won't pink.

Whats this pinking problem? I've never heard the expresion before. If its the car starting to jolt forwards and back at very low speeds where the engine seems to be revving, then suffering a bit of engine braking then I'm getting that at the moment running 99. (but I think it's just an oversensitive accelerator pedal bouncing up and down that causes it)

[Mikey G]

mikey_p said:

simes205 said:

If the timing is set up to run on 97 and you feed it 95 it will pink.
Tuning it to 95 will lose you some power but it won't pink.

Whats this pinking problem? I've never heard the expresion before. If its the car starting to jolt forwards and back at very low speeds where the engine seems to be revving, then suffering a bit of engine braking then I'm getting that at the moment running 99. (but I think it's just an oversensitive accelerator pedal bouncing up and down that causes it)

It will be a light rattling/knocking sound from the engine, most noticable when the engine is under heavy load at low engine speeds.

[simes205]

mikey_p said:

simes205 said:

If the timing is set up to run on 97 and you feed it 95 it will pink.
Tuning it to 95 will lose you some power but it won't pink.

Whats this pinking problem? I've never heard the expresion before. If its the car starting to jolt forwards and back at very low speeds where the engine seems to be revving, then suffering a bit of engine braking then I'm getting that at the moment running 99. (but I think it's just an oversensitive accelerator pedal bouncing up and down that causes it)

Nope that's just the fuel cut off trait thing you get with the Jetronic set up. You learn to ride the clutch to combat it in traffic.
Running Motronic these days so I don't have that problem.

[mikey_p]

simes205 said:

mikey_p said:

simes205 said:

If the timing is set up to run on 97 and you feed it 95 it will pink.
Tuning it to 95 will lose you some power but it won't pink.

Whats this pinking problem? I've never heard the expresion before. If its the car starting to jolt forwards and back at very low speeds where the engine seems to be revving, then suffering a bit of engine braking then I'm getting that at the moment running 99. (but I think it's just an oversensitive accelerator pedal bouncing up and down that causes it)

Nope that's just the fuel cut off trait thing you get with the Jetronic set up. You learn to ride the clutch to combat it in traffic.
Running Motronic these days so I don't have that problem.

Hmmm....I'm not a fan of riding the clutch. But at least I know what causes it though. cheers. Certainly seems like a lot of stuff to learn about this car. But it's oh so worth it

[Rob_the_Sparky]

mikey_p said:

In the manual it says do not use 95 ron fuel, and to use 97 or higher ron. However I can pretty much gauruntee (I can never spell that word) that mine hasn't been run on high octane fuel all it's life.
How would this affect the engine?

I have already used a tank of Tesco 95, and the car felt responsive and fast enough, then I ran it empty and used a tank of Tesco 99, and I couldn't notice any difference, and if anything it felt slightly less torquey. What do you lot think on this matter?

Thanks

There is no point in swapping fuel without adjusting the ignition timing to suit. No ignition timing change and you will not benefit from the decent fuel.

If you are running on 95 RON without pinking then your ignition timing is retarded. You will be down on power and engine will feel a bit flat. You may also have poorer fuel consumption and sometimes idle can suffer.

Rob