What octane gas on compression ratio 11.8:1

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Tommiee

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My fillercap says use minimum RON98 during normal use and RON95 at emergency use ( top off asap with higher octane )

Got my Lupo Gti chiptuned a while ago, should i now use a even higher grade of octane?

Original 125hp from a 1.6 16v 4cylinder

Today 161.2hp at the fly ( 900 kilogram car :d)
 
Well, I think 98RON is the highest octane widely available so the tuner must have considered that. The engine has knock control so I wouldn't worry about that. You could ask from the place you got the tune?
 
Its going to depend on what the tuner says. More than likely the requirement is for the highest readily available octane, here in the States it's generally 91 R+M/2, sometimes they'll tune for 93 but in some states, 93 is not available.

The compression ratio is only a part of the equation. There are cars running 12:1 C/R using 87 R+M/2 (standard grade) here in the States.
 
Sometimes they tune some of the knock control out, if the knock sensor is known for false positives.

If you're going to play, pay. More than 100 hp per liter, N/A, is a little high strung.
 
So it's not neccesary to go higher than 98RON?

Experimented with ethanol for the higher octane, but it throws a CEL @ 20% E85 or more.

When i read it out with the ELM327 it gives lean mixture as a fault code..
 
Yea you need to tune for higher levels of e85 because it takes more fuel to air ratio. Sometimes bigger injectors are also required.

Basically the more Ethanol % you put in the more you need to use.. so this has to be accounted for in the tune.

Also I know nothing of that engine but anything over 10-15% ethanol can be troublesome unless the car is designed for e85 use.

If you have the ability to have multiple tunes you could get a e85 tune (if car is capable)
a highest available gas octane tune (98 ron for you?)
a factory/low octane tune.

Last time I had a tuned vehicle I ended up with
factory tune, low octane/economy tune, high octane performance tune (93 octane us formula)
 
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Originally Posted By: Tommiee
So it's not neccesary to go higher than 98RON?

Experimented with ethanol for the higher octane, but it throws a CEL @ 20% E85 or more.

When i read it out with the ELM327 it gives lean mixture as a fault code..


You really should contact the tuner to get their suggestion.
 
Were you dyno tuned? If so often the tuner will put the fuel type in the info box on the dyno print out. Best to stay with what the car was tuned with for sure. What fuel was in the car when you took it to be tuned? Most tuners would not change the fuel unless you told them to do so. Not here at least.

If for some reason (knock) they had to up the fuel quality, It would have been irresponsible of them not to inform you that you needed to run a specific grade or higher following the tune.
 
I don't know how hot it gets in your part of Holland, but you could add some xylene/tolulene to the 98 for a little margin of safety during the summer months.

But YES, like the others have stated I would check with the tuner to see what they say, and exactly WHAT they did to get that power density besides the higher static comp. ratio (timing advance, knock sensor de-activation, etc.).
wink.gif
 
Did some mods before the chiptuning.

Spaghetti exhaust manifold
Open cells catalic
Cold air intake with green filter

And the chiptuning
 
Got VAG-COM and started logging on timing advance.

Still pulls the timing around 4 degrees on RON98. when I mix 10% ethanol it goes back to 1 degree and when filling up in germany with ARAL Ultimate RON102 it goes completely to 0 degrees. I can definately feel the difference in pickup and overall drivability with the RON102. I live nearby the german border so it isn't a problem to get the ARAL 102. It costs just as much as RON95 here in holland..
 
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