DirtyVegasTT

So I am lucky enough to only get 91 here in Nevada. Seems from what I have read that 4.0T on even stock ECU will take advantage of 93 and create more power, not sure if this is true... but anyhow, has anyone tried to up the octane with an octane booster?

I ordered Torco Accelerator because it had good reviews online just to try it out. Maybe a small power bump can be had for some of us stuck with 91?

Jack88

Well, I can tell you I have never noticed any difference. It might make a minute difference at the track, but I promise you that you won't be able to tell. Not at all.

DirtyVegasTT

Great... lol

DirtyVegasTT

So for the last 2 tanks I have been using an octane booster, and my car runs AMAZING on dynamic Drive mode on 91 at 110 degree heat with AC on full.

I don't know if its the octane booster or if it is in my head, but after this I am no longer seriously considering any ECU or Piggy Back mods.

snagitseven

I'm pretty sure it's in your head. The difference between 91 and 93 octane is very small and would not be noticeable in daily driving even in Dynamic mode. More importantly, is this "booster" doing anything detrimental to your engine over time?

On different note, while the focus is on fuel efficiency and engine life vs. performance. it would be beneficial to use Top Tier fuel. Here's an important independent lab study by Consumer Reports (a convincing read):

Study: Top Tier Gasoline Worth the Extra Price - Consumer Reports

MP4.2+6.0

Seconding on this, at least from now very dated experience. I tried an octane booster several generations ago on a normally aspirated I-5. I had bumped compression via Euro pistons when knock sensors were still very basic. Caused me to think you might look at plugs both "before" and "after." The stuff I used back then--one of the big names at the time--had a red dye to it. Funny thing was over time, my plugs also got little speckles of stuff on them...also sort of red colored. Remaining cans gathered dust after that.

DirtyVegasTT

I totally understand how this would apply to NA and supercharged motors... but is it possible that the newer Turbo motors are looking at the grade of fuel differently. Plenty of dynos out there that show the difference between 91 and 93 on Turbo engines. I think I'm at 95.

the_duke

I know from back in the day playing with my Dodge Daytona turbo that you can push the boost up a few PSI with a couple more octane numbers. With modern cars it comes down to whether or not the ECU will push more timing and boost with better fuel. I wouldn't be surprised if the Audi system pushes a little more timing if not more boost based on what it sees from the knock sensors. In the old days we had manual boost controllers and very archaic ecu tuning.

Having said all that many octane boosters can leave deposits. Do some research and find one that doesn't. I know royal purple is good.

DirtyVegasTT

Alright... Someone else needs try this on their 4.0T.

Running on 95 Octane for the last few weeks has transformed this car from what it was on 91 even during the peak heat in Vegas that reaches past 110 degrees.

Jack88

pla·ce·bo ef·fect
noun
a beneficial effect, produced by a placebo drug or treatment, that cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment.

Unless, of course, you are running a tune specifically for the higher octane.