Mixing regular and premium gas

[dn325ci]

I agree, pick one and stick with it.

You can of course use any.

But it takes the truck about 100 miles to fully adjust to the change, and it needs to experience the whole power band. For example, if you switch and then do 100 miles of exactly 65 MPH on cruise control without variable gradients, it will only "retune" for that condition and will need additional time to adjust to city stop n go driving.

Right. There is a hysteresis to it, and it takes some miles to fully settle in. 100 sounds high.

But "stick with it" has no scientific truth. You can cycle between 87 and 91/93 as much as you care to. In a modern engine there is no reliability or other benefit than the 10% performance gain/loss to staying with one or the other. There is no need or benefit to looking at it as a once in a lifetime forever and ever, amen kind of decision.

"Stick with it" as an engine oil strategy may have benefit, however.

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[The Real Maverick]

Right. There is a hysteresis to it, and it takes some miles to fully settle in. 100 sounds high.

But "stick with it" has no scientific truth. You can cycle between 87 and 91/93 as much as you care to. In a modern engine there is no reliability or other benefit than the 10% performance gain/loss to staying with one or the other. There is no need or benefit to looking at it as a once in a lifetime forever and ever, amen kind of decision.

"Stick with it" as an engine oil strategy may have benefit, however.

Just meant you will have substandard results for the first ~100 miles of a switch. Kind of counter-productive to switch often.

 

[dlhort1955]

I use 87 in my EB truck and 91 in my snowblower and lawnmower. The extra 91 at the end of the season goes in the EB and mixes with the 87. It is just gas.

 

[ryde4ever]

Ever hear of the very powerful placebo additive? The effects of placebo is guaranteed to give added horsepower and torque.ing berrer

I have heard it. But, I have also been driving, riding and working on cars and motorcycles for nearly 50 years. I can tell when an engine is running better. I am one of the first to tell people that if it says that a vehicle will run on 87 octane, don't waste your money on higher octane.
But many new vehicles adjust the knock sensor and timing based on what happens during combustion. It may run on 87 octane, but it may run better on 93. Computers do amazing things in engines today. But they are a pain when they break.

 

[dochawk]

For example, if you switch and then do 100 miles of exactly 65 MPH on cruise control without variable gradients, it will only "retune" for that condition and will need additional time to adjust to city stop n go driving.

That's not how modern adjusting engines work.

Sensors listen for pre-knock, and adjust timing before knock starts. (I have no idea how long boost adjustment takes). When ford increased the number of sensors, it supposedly obtained the ability to adjust cylinder by cylinder.

Adjustment time is in engine revolutions, not miles (at least when backing off to les aggressive). After backing up, it will slowly adjust to more aggressive until it finds what it algorithm defines as the upper end of "safe"

Therefore, E85 is only 70% ethanol at higher latitudes - the 30% gasoline is good for cold weather starting.

EUPTO85 ?

 

[colinl]

Sensors listen for pre-knock, and adjust timing before knock starts.

that is false. the knock sensor is a microphone and it's listening for detonation and pre-ignition and adjusting after they happen.

adjusting before is just following the fuel map.

 

[upnash]

When I use 87 unleaded I think the hybrid engine has a kind of a “growl” sound. I’m not saying it sounds like anything is wrong with the engine but just a slight growl sound. I often fill the tank with 87 unleaded and drive it til I’m down about 4 gallons then top it with 91 or 93 no ethanol recreational gas (whichever is available). The growl seems to disappear and I like how it seems to run. Don’t care how it’s blended or if it’s cheaper doing it another way, I hear it running quieter. Or if it’s just my imagination, in that case I imagine it running quieter and I like it

 

[SubtlySeismic]

I didn't realize how controversial this topic would be! People that think it's all a placebo effect will not be convinced by anecdotal evidence from all us randoms.

It would be nice to see a stock ecoboost maverick with 2 dyno runs on 87 and 93 octane gas for comparison. Anyone know if that has been done?

 

[Camdak]

I didn't realize how controversial this topic would be! People that think it's all a placebo effect will not be convinced by anecdotal evidence from all us randoms.

It would be nice to see a stock ecoboost maverick with 2 dyno runs on 87 and 93 octane gas for comparison. Anyone know if that has been done?

I think that’s a fantastic idea. Put this to bed once and for all!

 

[colinl]

It would be nice to see a stock ecoboost maverick with 2 dyno runs on 87 and 93 octane gas for comparison. Anyone know if that has been done?

Ford couldn't even be bothered to do it for the Maverick! (or any other 2.0 ecoboost model, that I have seen.)

But they did bother on the 2021 Bronco - it is actually rated on the specs with 87 and 93, and the 2.3 makes 25 more horsepower on premium.

 

[Meeka]

Ford couldn't even be bothered to do it for the Maverick! (or any other 2.0 ecoboost model, that I have seen.)

But they did bother on the 2021 Bronco - it is actually rated on the specs with 87 and 93, and the 2.3 makes 25 more,

Didn’t realize the 2.3 Bronco had 10.1 compression. Of course it will benefit from higher octane. But then again the 2.0 eco in our Mavs are 9.1 so a little higher octane would be beneficial.

 

[Meeka]

Screwed up on the above post again people, sorry, ‘puter illiterate!

 

[colinl]

Didn’t realize the 2.3 Bronco had 10.1 compression. Of course it will benefit from higher octane. But then again the 2.0 eco in our Mavs are 9.1 so a little higher octane would be beneficial.

so that's a very interesting thing you (respectfully) kind of stumbled onto.

22-24 Maverick exhibit is 9.3:1 with about 21 psi max boost. Bronco 2.3 is 10.0:1 with 17.5 psi max boost.

but then I look at the 25 Maverick ecoboost and whoa, it's 10.8:1 compression. I never noticed that before. I know it has both port and direct injection but now I'm wondering what else is different. same turbo or not, and what's the max boost?

the next 12 months will be interesting for people tweaking their 2025 Maverick ecoboost trucks.

 

[dn325ci]

j

I didn't realize how controversial this topic would be! People that think it's all a placebo effect will not be convinced by anecdotal evidence from all us randoms.

It would be nice to see a stock ecoboost maverick with 2 dyno runs on 87 and 93 octane gas for comparison. Anyone know if that has been done?

This has all been done by Cobb Tuning and probably others.

 

[colinl]

j

This has all been done by Cobb Tuning and probably others.

no their baseline is premium stock, not 87. I have not seen a 87 dyno plot.

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