Fuel type and HP on a Stock ST?

[MeeLee]

It's probably debated to no end, but,

I wonder if there are any hard numbers available running different fuel types in a stock ST, and their performance difference.

Like,
Is there a difference running regular 87 fuel, vs E15 (88octane), vs mid grade 89octane, vs premium 91 octane?

Or does the car select one of two fuel maps like some cars do? (eg: 87 and 91)

Thanks!

 

[Dpro]

Car is designed to run on 91 minimum. Suggested by Ford to run it on that. I woild not even think of running mine on anything less i.e. 87 or 89 lol. If anythingi want more octane not less.
Man up you bought a performance car. Fuel it like a performance and get over the fact that gas is going to cost a bit more.

 

[the duke]

Car is designed to run on 91 minimum. Suggested by Ford to run it on that. I woild not even think of running mine on anything less i.e. 87 or 89 lol. If anythingi want more octane not less.
Man up you bought a performance car. Fuel it like a performance and get over the fact that gas is going to cost a bit more.

It can run on 87 just fine. The car has knock sensors and CPS sensors and will retard timing until it’s good. You can run 87 without any issue, however you will see less horsepower and likely mileage. I’d just run the highest grade you can find.

 

[redmoe]

From the manual:
Minimal octane is 87 and best power on 93:

 

[Ford ST]

If you have 93 I would run it. I get it it cost more but to get the advertised horsepower it needs 93.

Sent from my LG-LS997 using Tapatalk

 

[Dpro]

It can run on 87 just fine. The car has knock sensors and CPS sensors and will retard timing until it’s good. You can run 87 without any issue, however you will see less horsepower and likely mileage. I’d just run the highest grade you can find.

It might run on 87 fine. You can do what you want. I am well aware of the fact the ECU will retard timing accordingly, that does not mean its ideal or well advised.

Look guys you’re nitpicking here. Fact is in Califonria 91 is the highest Octane we have and in the manual I got with my 2018 it recommends 91 Octane.

I personally feel when someone is asking about Octane its best to run the best premium you have available for the reason of better performance with our cars.

I also feel its a disservice to tell someone they can run 87 just because the manual mentions its capable of it. That is far from ideal and in an emergency situation one might not have an option.

You fricken bought a Turbocharged performance vehicle treat it like that! 87 octane gas is not doing that. Nor will you see optimum performance. Lol

This is my opinion and if you can’t accept it you can take it up in private message.

 

[redmoe]

It might run on 87 fine. You can do what you want. I am well aware of the fact the ECU will retard timing accordingly, that does not mean its ideal or well advises.

Look guys your nitpicking here. Fact is in Califonria 91 is the highest Octane we have and in the manual I got with my 2018 it recommends 91 Octane.

I personally feel when someone is asking about Octane its best to run the best premium you have available for the reason of better performance with our cars.

I also feel its a disservice to tell someone they can run 87 just because the manual mentions its capable of it. That is far from idea amd in an emergency situation one might not have an option.

You fricken bought a Turbocharged performance vehicle treat it like that! 87 octane gas is not doing that. Nor will you see optimum performance. Lol

This is my opinion and if you can’t accept it you can take it up in private message.

I don’t think there is an issue with your opinion. Most folks on here will opt to run the highest octane available.

The OP was looking for information on what the difference would be in performance based on different octane fuels. Just like some folks may want to “waste” their money on mods that have little gain (exhaust/intakes) others may want to sacrifice performance for fuel cost. In the end this is still an inexpensive car that some folks may be stretching their budget to purchase and may only be able to afford premium fuel for the occasional fun drive.

 

[Jerickson88]

Run what you want. Just realize mileage and performance may be the sacrifice, but you won’t hurt your car, otherwise Ford wouldn’t offer a warranty to support their manuals claims for fuel requirements

I have no idea what the dealer put in the car when they did the courtesy fill up, but it was fun either way. I’m exclusive on 93 now, because of the AP3.

 

[alexrex20]

 

[stascom]

Is there a difference running regular 87 fuel, vs E15 (88octane), vs mid grade 89octane, vs premium 91 octane?

It's a turboed car... of course, there is. Don't know what mechanisms it uses to adjust ECU maps but it absolutely reduces timing with low-octane fuels.

 

[LaserWhisperer]

Anyone ever fill up with diesel??

 

[TyphoonFiST]

Anyone ever fill up with diesel??

Errrr....

 

[Jerickson88]

It's a turboed car... of course, there is. Don't know what mechanisms it uses to adjust ECU maps but it absolutely reduces timing with low-octane fuels.

As long as the ecu and the rest of the car can adjust for the octane, there is no issue. Now if it cannot compensate by retarding timing, that’s when we have issues.

 

[SirThomas88]

People, the OP's question is very specific. does anyone have any hard NUMBERS of the HP difference between running the different fuels

Sent from my iPhone using Tapatalk

 

[Jerickson88]

People, the OP's question is very specific. does anyone have any hard NUMBERS of the HP difference between running the different fuels


Sent from my iPhone using Tapatalk

It is an interesting thought. It would be interesting if there was an 87 slot on the OtS maps for that once in a blue moon where the station is out of premium and midgrade. I’ve seen it happen. Like an 87 Econ map.

 

[Quisp]

Some reference.

Map Peak Gains Largest Gains
Stage1 91*
+2% HP / +19% TQ

+4% HP / +23% TQ
Stage1 93
+2% HP / +21% TQ

+5% HP / +26% TQ



Stage2 91
+7% HP / +22% TQ

+12% HP / +27% TQ
Stage2 93 +9% HP / +24% TQ +14% HP / +29% TQ



Stage3 91 +13% HP / +33% TQ +21% HP / +39% TQ
Stage3 93 +15% HP / +35% TQ +23% HP / +41% TQ

 

[worker88]

This should give you an idea.

https://youtu.be/oYsZFu3pmIA

I also think one of the European owner manuals has the power information per octane listed a little more specific than the US version.

 

[XR650R]

Anyone ever fill up with diesel??

I did! The difference in power was explosive!

 

[LaserWhisperer]

I did! The difference in power was explosive!

Light trolling is fun

 

[MeeLee]

This should give you an idea.

https://youtu.be/oYsZFu3pmIA

I also think one of the European owner manuals has the power information per octane listed a little more specific than the US version.

Thank you!
This post was helpful!

It appears that the difference is only a few percent between 91 and 87.
87 octane => 160-170HP
91 octane => 170-180HP
I suppose that's to the wheel.

It's something, but not really that amazing.

I wish the person of the youtube video had the opportunity to try out some Ethanol blends too.