87 or higher based on this?

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I have a 2018 Fusion Hybrid with 4k miles and the manual states the following:

Your vehicle is designed to operate on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87.
For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.


Thoughts? I never even considered filling it with 91 until I saw that today.
 
I've had owners manuals(wifes Lexus RX) that stated the same thing.
In some higher altitude states, there is octane that is 86 instead of 87. However, I have never gotten better fuel economy nor any noticeable performance gains by using higher octane 91 or 93.

Maybe, just maybe, if I paid quite close attention, I may notice a bit better throttle response but, not actual power of anything that I ever owned.

I did notice the difference in my SIL's BMW Z4 with higher octane compared to lesser octane fuel but, this 3.0i I6 is a different beast as I would think all high(er )performance cars would be.
 
Originally Posted By: gregk24
Is your engine knocking? If not I wouldn't worry about it.


This may sound stupid, but I don't know what that would sound like.
 
Originally Posted By: Unearthed
Originally Posted By: gregk24
Is your engine knocking? If not I wouldn't worry about it.


This may sound stupid, but I don't know what that would sound like.


http://bfy.tw/HRmE

quick search answers your question...
 
As altitude increases, less atmospheric pressure is available to fill the cylinders;

Less air = less power = less need for octane
 
Originally Posted By: Linctex
As altitude increases, less atmospheric pressure is available to fill the cylinders;

Less air = less power = less need for octane


True for non turbo vehicles.

However, the Ecoboost line of turbocharged engines absolutely will perform better on higher octane, regardless of altitude.
 
Both of my cars are "Premium Recommended" and run like [censored] on regular. I can usually tell within minutes.

I wouldn't even think of using 87 in them.
 
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Originally Posted By: Unearthed
I have a 2018 Fusion Hybrid with 4k miles and the manual states the following:

Your vehicle is designed to operate on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87.
For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.


Thoughts? I never even considered filling it with 91 until I saw that today.


How much of your driving, if any, is spent at WOT?

If the answer to that is 'very little' or 'hardly ever', then running the premium fuel/higher octane gasoline will be a waste of money for you.

If the answer to that question is 'all the time!' or 'every chance I get!', then your car's engine will make use of any extra octane the gas you buy contains. In that scenario, the extra money required for higher grades of gasoline will not be wasted.

Notice I stopped short of saying the extra cost would be worth it in that last statement. No one but you can say if a higher gasoline bill is going to be worth it even when you know the engine will make use of the higher octane fuel being purchased.

It's a catch-22 almost...just because your engine makes use of the higher octane gasoline during periodic passing events doesn't necessarily mean the extra cost is "worth it."

Or maybe it does; that's your call.

NOTE: not to throw sand onto the point I was trying to make here, but even if you make the decision to run the higher octane fuel, you will likely see inconsistent results with the gasoline based upon where you buy it. That has been my experience anyway. Not all premium fuels are created equal, and I have plenty of datalogs to back that claim up. Top Tier premium > non-Top Tier premium (as a general rule), and premium gasoline from a no-name place which looks a little shady is usually going to be the worst performing of them all. That's been my experience with gasoline and the varying octane ratings it comes it around here.
 
Originally Posted By: The_Nuke
Originally Posted By: Unearthed
I have a 2018 Fusion Hybrid with 4k miles and the manual states the following:

Your vehicle is designed to operate on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87.
For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.


Thoughts? I never even considered filling it with 91 until I saw that today.


How much of your driving, if any, is spent at WOT?

If the answer to that is 'very little' or 'hardly ever', then running the premium fuel/higher octane gasoline will be a waste of money for you.

If the answer to that question is 'all the time!' or 'every chance I get!', then your car's engine will make use of any extra octane the gas you buy contains. In that scenario, the extra money required for higher grades of gasoline will not be wasted.

Notice I stopped short of saying the extra cost would be worth it in that last statement. No one but you can say if a higher gasoline bill is going to be worth it even when you know the engine will make use of the higher octane fuel being purchased.

It's a catch-22 almost...just because your engine makes use of the higher octane gasoline during periodic passing events doesn't necessarily mean the extra cost is "worth it."

Or maybe it does; that's your call.

NOTE: not to throw sand onto the point I was trying to make here, but even if you make the decision to run the higher octane fuel, you will likely see inconsistent results with the gasoline based upon where you buy it. That has been my experience anyway. Not all premium fuels are created equal, and I have plenty of datalogs to back that claim up. Top Tier premium > non-Top Tier premium (as a general rule), and premium gasoline from a no-name place which looks a little shady is usually going to be the worst performing of them all. That's been my experience with gasoline and the varying octane ratings it comes it around here.


It is actually more important during light acceleration at highway speeds. Very lean burn/high heat. At WOT it runs very rich, so less likely to see damage then.
 
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My take is that your car will run fine in 87 but not optimally. Next time you fuel up fill it with premium. If you sense no discernible difference then you have your answer. My Mazda came with 87 from the dealer but when I refueled with Shell 91 I noticed a difference right off the bat. I’ve stuck with it since. There are also reports that running higher octane fuels helps to prevent or decrease fuel dilution. So far I haven’t noticed any but that is using my Mk 2 nose sensor and not a uoa.
 
My FXT's manual states that 93 is recommended, 91 is fine, and down to 87 will not damage anything but the car might not run very well.
When I was throwing weird CELs not long after I bought the car, the techs at the local dealer said I had no right to come whining to them about CELs if I didn't run SHELL 93 (had to be that brand!!!)...wonder what Subaru of America would have thought of that remark. The fix was some software tweak that had nothing to do with octane.
I almost always run 93, have also tried 94 in Canada and putting about 1/3 of a tank of 100 octane racing unleaded in with 93 just for fun. Had a couple of tanks of 91 when I just couldn't find 93 up in the NH mountains...the car has pretty much always felt the same.
I'd say have a little fun with it and try premium and silver to see what you think. I know light knocking can be quite harmless, but I sure wouldn't want to run gas that made my car do it. Modern knock control systems make most cars very forgiving of octane as far as actual damage occurring.
 
Originally Posted By: Char Baby

In some higher altitude states, there is octane that is 86 instead of 87. However, I have never gotten better fuel economy nor any noticeable performance gains by using higher octane 91 or 93.


I've seen 85 octane in mountain towns. The issue with filling up with lower octane at altitude is if you then go down the mountain to a lower altitude you could have an issue with detonation. IMO this is what Ford is trying to avoid. But if you're going to be in the mountains for a full tank or close to it, the lower number should be ok....note this is for NA engines only.

I have had 1 or 2 vehicles that seemed to run smoother on higher octane, but with no driving differences.


Originally Posted By: Cujet
Originally Posted By: Linctex
As altitude increases, less atmospheric pressure is available to fill the cylinders;

Less air = less power = less need for octane


True for non turbo vehicles.

However, the Ecoboost line of turbocharged engines absolutely will perform better on higher octane, regardless of altitude.


Exactly; with a turbo you want to maintain minimum octane at all times since even at higher altitudes you are still getting full sea level atmospheric pressure into the cylinders.
 
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It all depends on where you are? Your local atmospheric conditions (higher humidity?). How you drive, as in "in it at every on ramp"? Me, I'd rather slow down if I have to, than pull out in front of somebody at speed ... AND, it depends on how your 'puter handles timing?

If it pings lightly and occasionally, you are getting all you can from a fuel grade. If it never pings even going up a steep hill, you are not advanced enough to get all MPG the motor/fuel can ...

Try a tank and see what happens ... Take note of acceleration and hill climbing ability, etc. Then decide
smile.gif
 
Originally Posted By: Cujet
Originally Posted By: Linctex
As altitude increases, less atmospheric pressure is available to fill the cylinders;

Less air = less power = less need for octane


True for non turbo vehicles.

However, the Ecoboost line of turbocharged engines absolutely will perform better on higher octane, regardless of altitude.


The question is how much better will the EcoBoost engine perform with 93 vs 87 octane if you don't push it constantly in your everyday driving. And how much extra are you spending per gallon for 93 octane. The extra cost is easy for me to identify, it's usually at least $0.60 a gallon. That's about $11 per 19 gallons, not cheap if your not racing or the engine doesn't absolutely require it. Last year we drove to Key West from NJ in our new 2017 2.3 EB Explorer. I used 93 octane 90% of the time and mixed 89 octane in 10% of the time. We averaged ~24 mpg. This year we're going back down and and I'm going to use 87 octane and we'll see what the mpg averages. The only time I need extra power, whether the higher octane helped is unknown, is the mountains in VA and avoiding idiots on the road. The UOA's using 93/89 vs 87 octane didn't show any difference in fuel dilution or lower flash point.

Whimsey
 
Originally Posted By: mightymousetech


It is actually more important during light acceleration at highway speeds. Very lean burn/high heat. At WOT it runs very rich, so less likely to see damage then.


I am not familiar with the phrase 'light acceleration', is that a regional thing or something?

Based upon the context of the sentence, it sounds like it means 'to accelerate at less than WOT/100%'.

Is that right? No, that can't be right...going WOT but without the WO part is crazy...it's madness!!

No, no, no, I cannot stand for this...if we allow non-WOT acceleration to become 'a thing', then what is next?!?

Cats and dogs living in peace and harmony...black becomes white...up is suddenly down...left/right/middle/sideways....

AAAAAHHHHHH!!!!!!


No sir, anarchy shall not prevail in my world. All acceleration is to be done at maximum throttle or NOT to be done at all!

That's the rule, and the sooner we all learn to accept it and abide by it, the happier we will be!
 
Originally Posted By: mightymousetech
Originally Posted By: The_Nuke
Originally Posted By: Unearthed
I have a 2018 Fusion Hybrid with 4k miles and the manual states the following:

Your vehicle is designed to operate on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87.
Some fuel stations, particularly those in high altitude areas, offer fuels posted as regular unleaded gasoline with an octane rating below 87.
For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended. The performance gained by using premium fuel is most noticeable in hot weather.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage.


Thoughts? I never even considered filling it with 91 until I saw that today.


How much of your driving, if any, is spent at WOT?

If the answer to that is 'very little' or 'hardly ever', then running the premium fuel/higher octane gasoline will be a waste of money for you.

If the answer to that question is 'all the time!' or 'every chance I get!', then your car's engine will make use of any extra octane the gas you buy contains. In that scenario, the extra money required for higher grades of gasoline will not be wasted.

Notice I stopped short of saying the extra cost would be worth it in that last statement. No one but you can say if a higher gasoline bill is going to be worth it even when you know the engine will make use of the higher octane fuel being purchased.

It's a catch-22 almost...just because your engine makes use of the higher octane gasoline during periodic passing events doesn't necessarily mean the extra cost is "worth it."

Or maybe it does; that's your call.

NOTE: not to throw sand onto the point I was trying to make here, but even if you make the decision to run the higher octane fuel, you will likely see inconsistent results with the gasoline based upon where you buy it. That has been my experience anyway. Not all premium fuels are created equal, and I have plenty of datalogs to back that claim up. Top Tier premium > non-Top Tier premium (as a general rule), and premium gasoline from a no-name place which looks a little shady is usually going to be the worst performing of them all. That's been my experience with gasoline and the varying octane ratings it comes it around here.


It is actually more important during light acceleration at highway speeds. Very lean burn/high heat. At WOT it runs very rich, so less likely to see damage then.


This is interesting to me because this is a hybrid and driven pretty gingerly. The thing about WOT is I rarely get there because the battery will start to assist if I press the gas past a certain point. Occasionally I will hit a hill with low battery and have to give it more gas than usual to maintain speed.

To be honest I don't really care about the extra money if it gives some sort of benefit. I don't want to spend it though if I get absolutely nothing out of it. I'm coming from a car that required 91 so I'm sorta used to it. I was pretty psyched to get 8-10 more mpg AND drop from 91 to 87 though.
 
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