[Devas]

Lately I'm getting a throttle cut off feeling at 3000RPM on 1st and 2nd gear. It resumes after feeling like I pressed on the brakes for about a second. If I slowly get to 3000RPM on 1st gear, its not there.

Could it be bad Ultra 94 gas? Too much ethanol in the current batch?

[lcg]

When I spoke with agents at cobb the first thing they asked me was if I was from canada. After confirming that, they suggested not to run 94 petro canada fuel because of the ethanol. Agent said shell 91 has more octane then 94 petro believe it or not. He also advised not to run aggressive map because of our fuel. I think if you run STP octane booster with shell 91 you'll probably be good with aggressive. Check your spark plugs too

[jonmaceng]

I had the cobb tune, and I always got better performance on shell 91 compared to ultra 94. Just my 2 cents

[Tzu]

I've always had better performance and tunability from PC 94. 10% E is fine, as stated in the user manual.

[MrPig]

Petro94 has better knock resistance, although my STI has been feeling slower the last two tanks. From what I gather, the new Esso 94 is ethanol free.

[dbworld4k]

AFAIK, only Shell 91 is ethanol free.

[Glowin]

I'm running same setup. My throttle doesn't feel like it's off around that point, but rather, it feels like a big kick happens.

I use Chevon 94, which clearly says on the pump, is ethanol free. Cobb told me the same thing (that our 94 gas is actually worse than 91) when I contacted them about a few timing drops I was seeing when I did logs.

I then got a bottle of Lucas Octane Booster (and you don't need the whole bottle for one tank either), and the corrections disappeared! (If you search, NOS and Torco are the only two other brands that people say work)

I never got a reply as to why that was when I posted it or asked Cobb, but I'll run it when I track my car to be safe, not every day though. Could be my intake valves, which I'll get done in the next few months, and see if it changes anything. My plugs only had 6,000 miles on them at the time of the logs.

You can check out my logs here: http://www.datazap.me/u/Glowin

[11SEC]

Isn't E85 based on ethanol?

[rockblock]

Originally Posted by jonmaceng

I had the cobb tune, and I always got better performance on shell 91 compared to ultra 94. Just my 2 cents

Did you also try Stage 1 Sport/Aggressive with these octanes?

[Glowin]

Originally Posted by rockblock

Did you also try Stage 1 Sport/Aggressive with these octanes?

Now that you have bumped a 2-year-old thread… I am curious if his findings were on the Sport map, or the Aggressive map.

I've been too lazy to test myself and do logs to check, but I can't imagine you could run the Aggressive maps on 91 Shell. Even the map notes from Cobb indicate that you need minimum 92 octane. So it's not really apples to apples comparison running Aggressive maps on the Chevron 94 octane vs. Sport maps on Shell 91 octane.

[marcvtec]

funny stuff here.
even though 94 from PC (may contain up to 10% ethanol) it is still 94 octane.
only difference is because of the ethanol the engine temps might be slightly higher because of the alcohol burn factor. It still has better knock resistance then 91 octane (no ethanol).
Case closed.

[fredcase]

Originally Posted by marcvtec

funny stuff here.
even though 94 from PC (may contain up to 10% ethanol) it is still 94 octane.
only difference is because of the ethanol the engine temps might be slightly higher because of the alcohol burn factor. It still has better knock resistance then 91 octane (no ethanol).
Case closed.

Although Canadian gas uses the same formula for pump octane ratings, ro+mo/2. The testing variables are different. Canadian 94, is not even the equivalent of american 91. The ethonal has little difference when less than 20%

I have taken countless logs trying to track down timing drops. Husky 94 has yielded the best results. I now run about 5 liters of e98 in every tank of husky 94 and i have 0 timing drops at 17psi with 8deg timing. Jb4 map 2 with race backend flash.

Op, dont run aggressive on canadian gas, cobb themselves said it, and if you notice mhd puts cad 94 in the same class as acn91 (arizona California nevada) witch is the lowest quality fuel in america.

[rockblock]

I felt smoother acceleration with Ultra94 as well as better fuel consumption...I was averaging 10.6 l/100km with stock map + 91 octane and now with Stage 1 Aggressive running Ultra94 I am averaging 10.1 (I do 70% highway & 30% city)...so even though I'm paying a few bucks more for the Ultra94, it balances off financially, but I also get a much smoother and exciting ride...

Also, not sure about the US vs CAD "better" octane myth (anyone take actual samples and sent to the lab ???), but as far as I'm concerned, there's no turning back ))

Here's a link with some of my extra findings

http://www.e90post.com/forums/showthread.php?t=1320388

[fredcase]

Originally Posted by rockblock

I felt smoother acceleration with Ultra94 as well as better fuel consumption...I was averaging 10.6 l/100km with stock map + 91 octane and now with Stage 1 Aggressive running Ultra94 I am averaging 10.1 (I do 70% highway & 30% city)...so even though I'm paying a few bucks more for the Ultra94, it balances off financially, but I also get a much smoother and exciting ride...

Also, not sure about the US vs CAD "better" octane myth (anyone take actual samples and sent to the lab ???), but as far as I'm concerned, there's no turning back ))

Here's a link with some of my extra findings

http://www.e90post.com/forums/showthread.php?t=1320388

Pull some logs, then zip down to the states for a couple tanks of thier 93. Night and day difference.

Glad the 94 is working for you. I suspect the n55 have a little less back pressure and are less sensitive to octane.

[rockblock]

Originally Posted by fredcase

Pull some logs, then zip down to the states for a couple tanks of thier 93. Night and day difference.

Glad the 94 is working for you. I suspect the n55 have a little less back pressure and are less sensitive to octane.

For sure, next time I'm down there will try...bottom line is that 94 works better than 91 right now with the Stage 1 Aggressive...also truth be told, when I had stock map on it, I did run a few 94 tanks and didn't notice any difference at all...so I'm really only seeing the benefits in St1Agr mode