87 vs 89 vs 93 octane - my findings

[LokiWolf]

I don't doubt the EcoBoost produces more power with 93 but to what purpose? How many HP at 2000 rpm? Unless I'm drag racing Dodge Wildcats between stoplights on Hull Street Road that's the rpm the truck seems to cruise.

I find 93 makes no noticeable difference in normal driving or when towing my travel trailer. Including last month in the NC mountains with the camper behind.

As you know in Richmond 93 is always 60¢/gallon more than 87 regardless of the price of 87. $1.99 for 87, $2.69 for 93 a 30% increase in cost. When 87 was $3.00 93 was $3.60. Only 20% more cost but the same dollars. A typical 24 gallon fill is $14.40 extra for possible extra power I can't/don't use. I can get a 12-pack of beer for that.

-- Chuck

We get in to this every time.

I never mentioned the cost...it isn’t a factor to me...sorry. I bought an 8 passenger boat. I expect fill-ups to not be cheap. I used to drive a diesel 250 when it got close to $5 a gallon. Everything below that is just a win.

As far as the power, I guess Car & Driver’s numbers must be wrong. Seems like a big difference across the board to me...but OK.



I feel the difference, so did the wife. The MPG increase slightly lessens the hit of the cost.

It is tuned now, so 93 or E85 depending on the tune.

Bottom line, if you want to see the stock advertised power on an EB powered Expedition, you need to run 93, or at-least 91...if that is all you have.


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[JasonH]

It's strange that as you go up in altitude, the octane drops. Regular unleaded in Dallas, Texas is 87. Start traveling and in Amarillo, the regular unleaded is 86. Get up to Denver and it's 85. Altitude has something to do with it. That's why I don't worry about it. I run 85 in my '09 Expy EL with the 5.4 and it still runs like a scalded dog or a striped ape or whatever other comparison you name.

It's because the air is less dense, so the engine is at less risk of preignition because there is less air getting sucked into the cylinder. Turbos make up for some of the lower atmospheric pressure so it's still safer to run 87 minimum.

 

[JasonH]

I don't doubt the EcoBoost produces more power with 93 but to what purpose? How many HP at 2000 rpm? Unless I'm drag racing Dodge Wildcats between stoplights on Hull Street Road that's the rpm the truck seems to cruise.

I find 93 makes no noticeable difference in normal driving or when towing my travel trailer. Including last month in the NC mountains with the camper behind.

As you know in Richmond 93 is always 60¢/gallon more than 87 regardless of the price of 87. $1.99 for 87, $2.69 for 93 a 30% increase in cost. When 87 was $3.00 93 was $3.60. Only 20% more cost but the same dollars. A typical 24 gallon fill is $14.40 extra for possible extra power I can't/don't use. I can get a 12-pack of beer for that.

-- Chuck

It's noticeable, even at partial throttle. I only run 93 when towing but I wish it felt like that all the time. I found an e85 pump nearby so I might go with an upgraded fuel pump and e85 tune. Either that or an EV so I can floor it without fear of breaking anything or burning more dollars at the pump.

 

[LokiWolf]

It's noticeable, even at partial throttle. I only run 93 when towing but I wish it felt like that all the time. I found an e85 pump nearby so I might go with an upgraded fuel pump and e85 tune. Either that or an EV so I can floor it without fear of breaking anything or burning more dollars at the pump.

You can run a detuned E85 tune on the Stock pump...it rips!



MPG’s are less, but E85 costs less than 87...


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[JExpedition07]

We get in to this every time.

I never mentioned the cost...it isn’t a factor to me...sorry. I bought an 8 passenger boat. I expect fill-ups to not be cheap. I used to drive a diesel 250 when it got close to $5 a gallon. Everything below that is just a win.

As far as the power, I guess Car & Driver’s numbers must be wrong. Seems like a big difference across the board to me...but OK.



I feel the difference, so did the wife. The MPG increase slightly lessens the hit of the cost.

It is tuned now, so 93 or E85 depending on the tune.

Bottom line, if you want to see the stock advertised power on an EB powered Expedition, you need to run 93, or at-least 91...if that is all you have.


Sent from my iPhone using Tapatalk Pro

I agree with your logic Loki but something seems odd about those figures...not sure the source. I have a video of a stock 2007 5.4 3V Expedition on the dyno and it puts down 250 horsepower and 300 lb ft torque to the wheels in 2WD which translates to drivetrain losses of about 16% give or take from the crank ratings. 16% loss is in the average range. These figures show the gen 2 EcoBoost making more torque at the wheels than Fords flywheel rating which doesn’t make sense. Subtracting 16% assuming the same drivetrains you’d yield lower #’s.

 

[JExpedition07]

We get in to this every time.

I never mentioned the cost...it isn’t a factor to me...sorry. I bought an 8 passenger boat. I expect fill-ups to not be cheap. I used to drive a diesel 250 when it got close to $5 a gallon. Everything below that is just a win.

As far as the power, I guess Car & Driver’s numbers must be wrong. Seems like a big difference across the board to me...but OK.



I feel the difference, so did the wife. The MPG increase slightly lessens the hit of the cost.

It is tuned now, so 93 or E85 depending on the tune.

Bottom line, if you want to see the stock advertised power on an EB powered Expedition, you need to run 93, or at-least 91...if that is all you have.


Sent from my iPhone using Tapatalk Pro

OOPS, that’s the Raptor HO EcoBoost! My bad. Yes 475 lb ft out of 510 lb ft checks out much better lol!

 

[LokiWolf]

OOPS, that’s the Raptor HO EcoBoost! My bad.

Yeah, they used the Limited for their test which is as you said the HO motor. Same as the Navi.

Also here is the whole article for reference:

https://www.caranddriver.com/features/a28565486/honda-cr-v-vs-bmw-m5-ford-f-150-dodge-charger/

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[Expedition Dave]

I have a very well-tuned butt dyno. And I can tell just enough difference with 93 vs 87. I always run 87 (or 86 in Texas) until I get ready to tow, and then I run 93 just prior for a bit--to wake up whatever watches the octane. She is just a smidge quicker, especially at part throttle.

Under normal conditions, I'd rather save the $6-10 per tankful, until I think I need/should have it.

I do not know why they reduce octane as you get higher up in elevation. i know you make less power (is it 2 or 3% less per 1,000 feet for NA vehicles? I can't recall).

 

[JasonH]

I have a very well-tuned butt dyno. And I can tell just enough difference with 93 vs 87. I always run 87 (or 86 in Texas) until I get ready to tow, and then I run 93 just prior for a bit--to wake up whatever watches the octane. She is just a smidge quicker, especially at part throttle.

Under normal conditions, I'd rather save the $6-10 per tankful, until I think I need/should have it.

I do not know why they reduce octane as you get higher up in elevation. i know you make less power (is it 2 or 3% less per 1,000 feet for NA vehicles? I can't recall).

Less air in the cylinder at altitude because the air is less dense. Imagine a totem pole. At sea level you're on the bottom. As you go higher up, you have less weight bearing down on you from above. Lower air density means less risk of preignition under compression, so lower octane is ok.