Premium vs 87 stock tune?

[4V Mayhem]

It takes some time for the ECU to adjust...if you ask me. My GT had regular in it from the dealership. I ran that tank down as low as possible and filled up with 93. I didn't notice any difference. A week and a half later I filled up again with 93...noticed no difference. By the third time I filled up I had put it out of my mind. So I filled up with 93 and a couple days after that the car felt different. All in all it was a good month and a half and about 900 miles...as I don't put many miles on my GT. So don't expect immediate changes. By the time mine made any changes I had completely wrote it off, lol!!

Sponsored

 

[BmacIL]

The adaptive learn doesn't take that long. If anything changes, you'll notice a difference in 10-30 miles depending on driving conditions.

 

[Terminator2]

Interesting. I noticed the exact opposite with the gas here! 4 straight fill-ups with BP 93 (right by my house) and then I just happened to grab some Shell 93 on an empty tank a couple weeks ago. I wasn't expecting or looking for a difference but I noticed it very quickly.

Weird i thought it was a fluke but I've repeated it numerous times with the two stations near my house and the same results every time.

 

[BmacIL]

Weird i thought it was a fluke but I've repeated it numerous times with the two stations near my house and the same results every time.

I wouldn't think there would be that much difference in regional blends, but maybe?

 

[5.oh]

I figure I spent plenty of money for a "performance" car, why not put decent gas in it. I only run 91 or higher.

 

[dg108]

If the owner's manual suggests using premium for optimum towing performance then I would believe they are telling us it will perform better with premium.

 

[joleobee]

BP gas here has much better knock resistance than Shell. I actually notice a big difference on BP 93 vs Shell 93. My data logs reflect this as well.

Are all your BPs now Marathon gas stations?

 

[Derek@Lethal]

Are all your BPs now Marathon gas stations?

Soon they all will be. They have been doing the switch-a-roo here in S FL over the last year or so. All the old BP's around me that I can think of are now Marathons.

 

[4V Mayhem]

See the many different answers to one question? You'll notice that with every topic there will be many different answers some wildly opposite to others...because we're all experts who know everything about our car and other people's cars. The best thing to do is see for yourself. Try some good 93 octane gas from some of the top stations like Exxon, Mobil, Shell, etc. It'll be more expensive but a few tanks might end up costing an extra $25 altogether. If you don't notice anything after a good few miles, then wait a few more. Give it a few tanks if you still don't notice anything. If nothing still, then switch back to regular and see if any performance is lost. If nothing after that then I say do whatever you feel is better. 87 octane certainly won't harm your engine. So if there is no performance gains with 93 then save yourself some money and throw the cheap stuff in. But in any case, it could take a day, a week, a tank full, 2 tanks full, best way to know is to experiment.

 

[joleobee]

Soon they all will be. They have been doing the switch-a-roo here in S FL over the last year or so. All the old BP's around me that I can think of are now Marathons.

I hope the quality is just as good under Marathon.

 

[Jaehead]

Anyone have dyno figures of 87 vs 93 octane?

 

[BmacIL]

It's for the F-150, but you'll get an idea:
http://morepowertuning.com/images/MPT_Dyno_2011_F150_5.0.jpg

 

[4V Mayhem]

Anyone have dyno figures of 87 vs 93 octane?

Someone on another forum did that on a Coyote years ago and it was about 10-15 hp. I think it was a 2011. But for the S550 I was told the difference is less. I doubt that tho.

 

[jasonstang]

Someone on another forum did that on a Coyote years ago and it was about 10-15 hp. I think it was a 2011. But for the S550 I was told the difference is less. I doubt that tho.

I would say 3-4hp peak difference and 10-15hp difference mid range.
Again factory tune is very conservative at higher rpm. That's why a tune can give you 15-30hp at peak easily.

 

[Grintch]

You guys think Premium makes a diff with the stock tune on my 2015 GT? I am new the GT so sorry for all the dumb questions.

Seems like I saw a Ford estimate that 87 costs you 10hp in the GT, and 30hp for the EB.

I run 87 normally, then go to 93 for Autox or Track. But I can't say I notice the difference in power. I DO notice the difference in cost.

I have noticed a lot of the tuners, don't official support 87. I wish they would.

Sponsored