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circatee

Standard or Premium petrol for your ST?

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Not sure if I specifically asked this question, on this forum previously. 

But, for your ST, as a daily driver, do you use Standard or Premium petrol?

 

Thanks all

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Probably best for me to follow the manual, 91 or higher. And, 93 if looking to maximize the 335hp... 

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for ecoboosts, 93 is highly recommended for those looking for power or those who mash the wawa pedal on a frequent basis.  more octane = more available timing advance.

 

the real gains come after you put on an aftermarket tune.  mostly because the factory tune runs pig rich to protect the engine, so the tuners can lean it out without detriment.  but also because transmission shifting behavior is improved, faster and crisper.

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Premium only.

I have sams club so I'm paying 3.05 a gallon right now. Other gas stations in the area are charging 3.64. I pay for my sams membership in just a couple of fillups lol 

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add me to the 91 octane club. i didn't buy the ST to hobble it with low octane gas.

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I run 93 only. I always have tons of stop and shop gas reward points so I generally only pay $35-40 per tank. 

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I only have 91 where I live. I have to add a good octane booster to get close to 93 but it does certainly help. I am right now going to run an unleaded 108 race fuel with my 91. Should be equilvilant to around 98 to 100. Tune going in now and will test and data log.

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I use 91 octane when available because of the tune I put in... but I'm pretty much disappointed with the tune's results though... If I knew, I wouldn't have bought the tuner, it's not worth it.

Claude.

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On 10/4/2021 at 12:10 PM, 2FAST4U said:

I use 91 octane when available because of the tune I put in... but I'm pretty much disappointed with the tune's results though... If I knew, I wouldn't have bought the tuner, it's not worth it.

Claude.

 

I will be honest too, the 91 octane tune is pointless in my opinion. I am not having a lot of luck with the 93+ tune either. Or maybe I expect too much?

 

Right now from my previous tests, this is what I have gotten with the Dragy:

 

Stock tune, 91 octane with octane booster, 80' F at night at the strip 5300' altitude, basic 20 min cool down - 14.37ET @ 95mph

91 tune, 91 octane with octane booster, 78' at night on a Mexico street 5800' altitude, basic 20 min cool down - 14.42ET @97mph

93+ tune 1st ver,  91 octane mixed around 60/40 with 108 race fuel, 60' at night on a Mexico street 5800' altitude, 30 min cool down w/ water spray of intercooler(ambient temp when run starts) - 14.06ET @99mph

93+ tune 2nd ver (2'), 91 oct mixed around 60/40 with 108 race fuel, 60' at night on a Mexico street 5800' altitude, 30 min cool down w/ water spray of intercooler(ambient temp when run starts) - 13.99ET @99.30mph

 

I am going to the strip tomorrow and will be running a stronger blend of 108. Should be more like race fuel 70/30 with pump plus it will be like mid 70s and sunny. The reason I want a higher ratio is because I had an odd run where KR knocked a ton of timing out which killed power a lot in the midrange. Same night same conditions, etc. Tuner thinks octane is probably not where I think it is. How did I get a good run then a bad run? Data logs showed conditions actually slightly better on the run where timing pulled, Something does not make sense. I need to really study the logs to see if I am missing something.

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