EcoBoost on premium vs regular

[StevenCaylor]

For those of you with the 4 cylinder EcoBoost engines, have you noticed much of a difference in acceleration or fuel economy when running premium vs regular. My sister just bought a new EcoBoost Edge. She loves it so far.

[jcthorne]

Slight difference in performance with the 2.0EB in our Escape. Minor at best. No real change in fuel economy but it could be that I was using the throttle more when I had the premium in the tank.

[ldd]

I use 91 octane (that's "premium" by California standards) in my Focus ST. Reports from fellow owners suggest about 1-2 mpg improvement, which more or less equals the price difference. For the same dollars per mile, I'll take the premium. Not really noticeable in terms of daily driving, but the difference does show up on dyno charts starting at about 3500 RPM and becoming quite noticeable across the peak power band.

 

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Edited April 22, 2013 by ldd

[elhnet2000]

I am in CA and have used both 87 and 91. I don't really feel a performance difference either. For the price of gas out here, I don't see the need to make the extra spend.

[Bob Rosadini]

I was alternating between 89 and 93 in my SHO. Then decided that a steady diet of 93 gave me a bit more MPG-nothing scientifc-

[Gator06]

In Florida, we have 87, 89, and 93 at most pumps. I've been wondering if 89 is a viable compromise between additional performance and cost. Is there any advantage to running 89 to get some of the benefit of additional power/mpg at a cheaper price than 93? I'm not sure how the ECU operates on these engines. I seem to recall reading it basically has two mappings, one for regular and one for premium, but I can't seem to find the source of that anymore so I could be wrong. If thats true, then 89 would be a waste if it wasn't enough octane to trigger the "premium" mapping. However, if its truly variable, there could be some benefit of using midgrade. Any thoughts/experiences?

[akirby]

Not worth it. Premium isn't usually worth it either. Not enough of a benefit to outweigh the additional cost.

[GaryG]

In Florida, we have 87, 89, and 93 at most pumps. I've been wondering if 89 is a viable compromise between additional performance and cost. Is there any advantage to running 89 to get some of the benefit of additional power/mpg at a cheaper price than 93? I'm not sure how the ECU operates on these engines. I seem to recall reading it basically has two mappings, one for regular and one for premium, but I can't seem to find the source of that anymore so I could be wrong. If thats true, then 89 would be a waste if it wasn't enough octane to trigger the "premium" mapping. However, if its truly variable, there could be some benefit of using midgrade. Any thoughts/experiences?

 

Form what I read in Ford Powertrain Control/Emissions Diagnosis Manuals, there are short term fuel trim and long term fuel trim maps. It is important to stay with the same grade fuel because the short term fuel trim become long term maps in the KAM (keep alive memory) stored in the PCM. There is a factory default memory stored in the PCM that will reset if the battery is disconnected for more than five minutes. The corrections made to the default settings are tables that are referenced by engine speed and load. Learning the corrections in KAM improves both open and closed loop air/fuel ratio control. Short term fuel values are not retained after the engine is turned off.

 

Advantages:

 

short term fuel trim does not have to generate new corrections each time the engine goes into closed loop.

 

long term fuel trim corrections can be used both while in open and closed loop modes

 

There is a separate long term fuel trim value that is used for each RPM/load point of engine operation. Long term fuel trim corrections may change depending on the operating conditions of the engine (RPM and load), ambient air temperature, and fuel quality (% alcohol or oxygenates).

 

Choose the fuel grade recommended in your owners manual but if the manual says a higher octane will improve performance, ask yourself if you need more performance. Higher octane has additives to reduce the burn rate of the fuel to prevent engine knock. The PCM uses the knock sensor to retard spark timing to prevent knock also. If you are concerned about getting better MPG with higher octane fuel, ask yourself do I need the added performance according to what the manual says with a higher cost. Driving techniques can improve MPG much more than a higher octane fuel, so let the PCM just retard the timing and save at the pump. IMO, if I can run 87 octane, I will use 87 octane. I would not buy a car myself if the engine required high octane gas at today's prices.

 

Chose what octane you want, but stick with it so your long term fuel trim corrections stay consistent for the best MPG. Changing fuel octane or % of ethanol can reduce MPG until long term fuel trims have corrected.

[Gator06]

Form what I read in Ford Powertrain Control/Emissions Diagnosis Manuals, there are short term fuel trim and long term fuel trim maps. It is important to stay with the same grade fuel because the short term fuel trim become long term maps in the KAM (keep alive memory) stored in the PCM. There is a factory default memory stored in the PCM that will reset if the battery is disconnected for more than five minutes. The corrections made to the default settings are tables that are referenced by engine speed and load. Learning the corrections in KAM improves both open and closed loop air/fuel ratio control. Short term fuel values are not retained after the engine is turned off.

 

Advantages:

 

short term fuel trim does not have to generate new corrections each time the engine goes into closed loop.

 

long term fuel trim corrections can be used both while in open and closed loop modes

 

There is a separate long term fuel trim value that is used for each RPM/load point of engine operation. Long term fuel trim corrections may change depending on the operating conditions of the engine (RPM and load), ambient air temperature, and fuel quality (% alcohol or oxygenates).

 

Choose the fuel grade recommended in your owners manual but if the manual says a higher octane will improve performance, ask yourself if you need more performance. Higher octane has additives to reduce the burn rate of the fuel to prevent engine knock. The PCM uses the knock sensor to retard spark timing to prevent knock also. If you are concerned about getting better MPG with higher octane fuel, ask yourself do I need the added performance according to what the manual says with a higher cost. Driving techniques can improve MPG much more than a higher octane fuel, so let the PCM just retard the timing and save at the pump. IMO, if I can run 87 octane, I will use 87 octane. I would not buy a car myself if the engine required high octane gas at today's prices.

 

Chose what octane you want, but stick with it so your long term fuel trim corrections stay consistent for the best MPG. Changing fuel octane or % of ethanol can reduce MPG until long term fuel trims have corrected.

 

Great info, thanks! I think I'll use 87 once my new 2.0 Escape arrives, unless I plan on towing or carrying other heavy loads.

[GaryG]

Great info, thanks! I think I'll use 87 once my new 2.0 Escape arrives, unless I plan on towing or carrying other heavy loads.

 

Anytime Gator, do you still have your FEH?

 

I saw my neighbor towing his 17' boat with his new 1.6L Escape, so they must make a hitch for the new design Escape. I don't think the 2.0L EB Escape will have any trouble towing even with 87 octane.