Now that a lot of people have gotten their 15 Mustang's, just curious what octane rated unleaded gasoline you're running in your Pony car?? I haven't ordered mine yet (March I FINALLY get to order) but plan on running premium through it once it comes in.

 

87 in my V6.

 

BP 93 octane

Otherwise try to find at least 91.

I figure for the $.10 difference x 14-15gallons, its only an extra $1.50/tank and I need all the Hp I can get!

 

87 for daily use
93 for track days

 

91 is all I can find.

 

Diesel.

 

Normally 87 but I admit there is a significant power increase with 93, I can feel the difference. Will run more 93 now that gas prices are below $2.00.

 

93 - Usually Chevron.

 

I hear using diesel gives you immense torque gains on our 5.0s

 

Isnt this bad? I thought it takes a few thousand miles for the ECU to recalibrate for optimal burn?

 

Well it's a little more than that. I'd say $5 is a healthy benchmark. Where I live it's $2/gal vs $2.40/gal, so just over 6 bucks a tank difference, i.e. the cost of a cheeseburger.

 

I don't think so. It takes a while for the ECU to learn your driving habits and optimize engine control.
But for octane rating I though it just does closed-loop control on cam timing and A/F ratio and backs off when using 87 octane.

Does anyone know for sure?

 

I use 87 on my GT. It's an extra 60 cents for 93 in NJ. I don't think you'll see big performance gains from 93 if the car is all stock. One of these days I'll try 93 to see for myself. Mine is a DD and the only car I own so I'll keep it stock for reliability. In NJ car insurance is too much for an extra car, plus parking issues where I live.

 

I use 93 it actually seems to burn better and in all honestly last s longer than if I fill with 87 if I have to i just need to change the tune.

 

If I could buy 93 octane, I would. Just not available where I live.

 

Chevron is where I find it , it's too bad our gas here is so dirty, it's like every 6 months I have to pull my back seat to remove my fuel pump to clean the pick up sock , it gets so nasty, but after the car runs smooth & I go from say 300 kilometers a tank to like 400

 

My dealer sales guy seemed to be pretty knowledgeable about the 2015 Mustang. He actually owned a 2012 or 13 Mustang but had traded it in for an 2014 Edge. He told me it takes about a tank of gas for the ECU to pick up the octane rating change. I don't know if that's true or not but it sounds logical.

 

The GT and EcoBoost Mustang engines were designed and setup for 93-octane fuel. It is only through modern knock sensor and computer technology that the engineers made it possible to run 87-octane fuel, though this does not mean that you should run 87-octane fuel, only that you don't need to worry for those times that the correct octane fuel is not available.

As for Fuel Price, it doesn't matter if fuel costs $1.00 or $4.00 per gallon for the 87-octane cheap stuff. The cost differential between the low/high octane fuel has remained near constant, with 93-octane (for most city dwellers) costing approximately $0.30 to $0.40 more per gallon.

What's the real cost to run 93 vs 87 octane fuel? The difference is small enough that if you're concerned about 93-octane fueling breaking your budget then you bought the wrong car, and/or maybe you shouldn't have bought a new car at all.

If you drive high mileage like I do (24,000 miles per year), the cost is only $30.00 more per month or $360.00 per year to run 93-octane all year long.

 

Beautifully said.

 

Here, here!