Octane Ratings

[Frenchy]

@Nopalito has run 85 in his Ranger since he bought it new.

And it probably runs like shit

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[Frenchy]

Interesting. I've always used just regular 87 octane unleaded.

I played around with 91 octane, but noticed no difference whatsoever. (Possibly an increase of 1-2 mpg, but that within the placebo effect.)

Currently, 91 is running about 50-60 cents/gallon more than regular, so why spend that extra money if you don't see any noticeable benefit?

It depends on how you did the so called playing around. If you did one tank with mostly 91 and the rest 87, then you didn't see the full benefit. This is especially true if you went right back to 87. I recommend have a few full tanks of 91 and up in a row. Also drive it reasonably and you will see the increase. I saw an average of 1-2 on my 2019 when I had it and it felt a bit smoother vs 87.

 

[Nopalito]

And it probably runs like shit

I haven’t logged into R5G for probably 2 years.
No problems running 85 for the vast majority of the miles on my truck. It runs better on 85 than using 86 E15.

I also thought you sold your Ranger a long time ago

 

[Frenchy]

I haven’t logged into R5G for probably 2 years.
No problems running 85 for the vast majority of the miles on my truck. It runs better on 85 than using 86 E15.

I also thought you sold your Ranger a long time ago

I didn't sell mine. It got totaled......... For reasons this Forum will never let me live down(they were pretty ruthless about it to).........

Also I know your truck isn't getting good performance due to running lower than manufacturer recommend fuel. It has to do with knock and pinging. The higher the octane, the more resistance to knock and pinging due to not igniting the fuel as easily (due to pre-ignition). When I first got my Ranger in October of 2019 I was using 87 even up in Leadville. About a month or two later I switched to 91 and I noticed the difference(nothing neck breaking). The truck was running smoother and had better power delivery. Even the MPG went up by roughly 2. Of course tuning it later helped as well, but that was for other reasons

 

[Nopalito]

I guess being retired so long that I've never remember seeing this rating.

85 octanes? I can't remember seeing that option at the pumps.

How can turbo cars handle this? Heck my wife's car we used mid-grade (89). Ranger does (91).

On an article I read they call mid-grade (87)???

I use almost 85 exclusively in Colorado and I haven’t had any issues in 74,000 miles. I have tried the E15 blended 86 octane but my truck does not like it & it’s not worth the hassle 10c less.

 

[AzScorpion]

What mechanisms are available to the Executive Branch that a President can use to artificially lower gas prices? I’ve always anecdotally heard sayings such as this, but never heard the mechanics behind it.

I never said the president does it.

Just look back and almost every year right around election time the price seems to go down. Coincidence, I doubt it. There's always a way to manipulate numbers and prices especially for the short term depending on who's in office and what (and how much) their donors are willing to do. I'll leave it at that.

 

[Colo_Ranger]

Interesting. I've always used just regular 87 octane unleaded.

I played around with 91 octane, but noticed no difference whatsoever. (Possibly an increase of 1-2 mpg, but that within the placebo effect.)

Currently, 91 is running about 50-60 cents/gallon more than regular, so why spend that extra money if you don't see any noticeable benefit?

Same, I use 87.

87 at sea level is 85 at elevation. You're running low grade the same as we would up here. Mid ggrade is a scam, since the blend is like 80/20 (low/premium). You'd save money by filling up your own low/premium blend.

 

[Joeiconic]

I’m tuned and run 93 here in Georgia. Close to $5 a gallon currently.

 

[Nopalito]

The 85 vs 87 argument is one of my absolute favorites to have. Like Colo_Ranger said, 85 at 4,000ft+ is the same as 87 at 400ft in elevation. Not everyone lives in a flat & low elevation city.
Mid grade is for sure a scam and just use premium if you need the extra octane points.

 

[Titchadesh]

Not arguing here, just checking my understanding because I thought the old "higher altitude means you can safely use lower octane" logic doesn't translate as cleanly to modern engines as it did to old carbureted naturally aspirated engines.

Altitude lowers an engine's octane requirement primarily by lowering cylinder pressure. A turbocharger partially restores that cylinder pressure. Our Rangers' turbocharged engines can compensate for altitude by increasing boost, so a turbo engine may still generate substantial cylinder pressure at 4,000–5,000 feet.

I think saying that 85 at high elevation is technically equivalent to 87 at low elevation needs more elaboration.

Ford disagrees with that conclusion and even specifically call out to not use lower octane in higher elevations in the owner's manual. I don't think they do that to perpetuate a "mid-grade scam," but more likely because they understand that the ECU's knock control system can only do so much.

 

[Titchadesh]

I never said the president does it.

Just look back and almost every year right around election time the price seems to go down. Coincidence, I doubt it. There's always a way to manipulate numbers and prices especially for the short term depending on who's in office and what (and how much) their donors are willing to do. I'll leave it at that.

Don't leave it at that, I'm trying to learn! I am still trying to solve the mystery about how politicians can artificially lower gas prices right before an election. Maybe we can just add it to the mystery of Adam Smith's "The Invisible Hand" metaphor for supply and demand haha

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